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Quantitative assessment of resource-use efficient cropping systems: A case study for Ansai in the Loess Plateau of China
Abstract
Severe soil erosion and food security problems are the most important issues in the Loess Plateau of northern China, which are closely related to the over-cultivation and poor management of marginal land resources. Alleviation of these unsustainability problems requires, among many other things, alternative and innovative cropping systems. This paper describes the identification of such cropping systems and their quantitative evaluation. It uses an operationalized approach based on production ecological concepts, and the application of the simulation model EPIC for the case of Ansai County in the Loess Plateau. Based on four criteria, i.e. suitable land units, crop rotations, production situations, and agro-techniques for water and soil conservation, we identified 548 cropping systems. The yield potentials and efficiencies in terms of soil and nutrient conservation were quantitatively evaluated for each of the cropping systems. The results indicated that the low productivity, and serious soil and water losses in current cropping systems may be greatly alleviated by increasing nutrient inputs and use of soil conservation measures, such as growing crops in rotations with alfalfa, using crop residues as mulch, and furrow-ridging tillage. For most crops, the current yield may be at least doubled by good soil and crop management with appropriate inputs. The study suggests a range of crop rotations that satisfy food production, soil and water conservation and economic objectives to different extent. The results of this study can serve two purposes. First, they may help setting an agenda for empirical and experimental research aimed at the testing and improving of cropping systems, and second, the cropping systems can be input for an integrated land use study that weighs objectives at regional scale and reveals potential and strategic land use options.
... Soil loss in the Loess Plateau accounts for more than 90% of the total sediments entering the Yellow River (Chen et al., 2007). About 70% of the total area is affected by soil erosion, and 40% of agricultural lands suffer annual losses of more than 50 ton/ha (Lu et al., 2003). ...
... Xu et al. (2010) posit that gains in household income, program efficiency, and welfare will occur if farmers are given greater autonomy about what fields, if any, to include in a program like GfG. Specifically, Lu et al. (2003) and Dogliotti et al. (2004) present solid evidence that conservation cropping in the Plateau can effectively reduce soil erosion while also maintaining agricultural production because agricultural systems, land types, and cropping techniques vary across the steeply sloping lands. Furthermore, a 2005 World Bank project reports that farmers' incomes rose dramatically and erosion was reduced when farmers were introduced to sustainable farming practices (World Bank, 2005). ...
... While each method has advantages, abatement cost curves reflect the polluter pays principle and present lower costs in comparison to expensive surveying methods required for contingent valuation (Molinos-Senante et al., 2010). Since agricultural systems and fields in the Loess Plateau are heterogeneous (Lu et al., 2003), so are the field-level costs of avoided soil erosion damage within the system. A multitude of factors contribute to soil erosion propensity and soil erosion tolerance on individual fields or individual watersheds , leading to heterogeneous on-farm costs at the field level. ...
... Section 3 contains a description of the Loess Plateau study area and the simulation data, created from the Environmental Policy Integrated Climate (EPIC) model (Gassman et al., 2005; Williams et al., 2006). This simulation is conducted on more than 2000 different cropping-system variations that are based upon Lu's original work (2000) and a subsequent publication that uses approximately 500 of these cropping systems (Lu et al., 2003). The sustainability measurements evaluate different combinations of crop rotations, production situations, terracing techniques, tillage techniques, crop residue management techniques, mechanization levels, and land units. ...
... This section describes how different conservation techniques are aggregated into a linear regression to derive the marginal impacts of crop type, cropping technique or land type on SV and SE. The following simple linear regression is formulated based upon data collected by Lu et al. (2003) in order to analyze which cropping practices and conservation techniques enhance or deplete sustainability: Y i ¼ β 0 þ β 1 ROT i þ β 2 RES i þ β 3 CONT i þ β 4 PRO i þ β 5 MEC i þ β 6 TER i þ β 7 SLP i þ ε i ð14Þ where the dependent variable Y i is the SV or SE of the ith cropping system, calculated from the SV approach. Different cropping practices, land units and conservation techniques (shown in Table 2 ...
... It is characterized by steep sloping lands, which are marginally suitable for cropping. The rate of soil loss is generally more than 50 t/ha in the hilly area (Lu et al., 2003). As noted in the introduction, although land use changes may be extreme, the focus of this paper is to investigate how to balance environmental objectives with continued crop production. ...
China's Loess Plateau is a highly distressed region where intensive crop production has been undermined by high soil erosion rates that threaten the long-term livelihood of its inhabitants. Regional policy goals aim to balance economic performance with the sustainable use of natural resources. From a practical perspective, challenges arise when measuring sustainability levels that mix multiple dimensions, scales, and benchmarks. This study addresses these challenges by comparing the sustainability of agricultural systems across varied crops, land types, and cropping techniques in China's Loess Plateau. Sustainability levels for each system are compared to benchmarks using data envelopment analysis, which is then used to calculate a sustainable value (SV). The SV approach provides a monetary measure of sustainability that includes economic, environmental and social dimensions. Results demonstrate that the most sustainable agricultural systems in the Loess Plateau involve machine intensive cropping systems, a corn–soybean–corn rotation, mulching, furrows ridging, and bench terracing.
... Food self-sufficiency was a condition for each optimization, in which one objective variable was optimized while other objectives were used as constraints with specified target values or as a non-binding variable. Floodplains, existing terraces, gently sloping, moderately sloping, steeply sloping, very steeply sloping (see Table 3) Yield level 3 Attainable irrigated yield with ample supply of nutrients and water, attainable rainfed yield with ample supply of nutrients but no irrigation, and N-limited yield with limited or without external N use for rotations without or with alfalfa, and no irrigation Mechanization level 2 Semi-mechanized with use of power-driven traction and herbicides, and non-mechanized with hand labor, animal traction and manual weeding (non-use of machinery and herbicides) Agro-technical measure 4 Contoured tillage with crop residue removed, furrow-ridging tillage with crop residue removed, contoured with crop residues left on-field, and furrow-ridging tillage with crop residues left on-field Terracing type 2 Level bench terracing with the slope land fully terraced, and spaced terracing with the slope land partly terraced a Detailed descriptions are given in Lu (2000) and Lu et al. (2003Lu et al. ( , 2004. b A: alfalfa; # 3 (or 4 or 5) stands for the number of growing years of alfalfa; wht: winter wheat, mlt: millet, soy: soybean, pota: autumn potato, and pots: summer potato. ...
... Quantification of the production activities was based on a target-oriented approach (Van Ittersum and Rabbinge, 1997;Hengsdijk and Van Ittersum, 2002), in which target outputs were set first, and then the required inputs such as nutrients, capital and labor to realize them were calculated. A quantitative land evaluation was conducted using the EPIC model (Sharpley and William, 1990) to quantify interactions between yields, soil loss and effects of various agro-techniques and land conditions (land units), and the results have been preliminarily validated with empirical and experimental data from Ansai and the Loess Plateau (Lu, 2000;Lu et al., 2003). Target yields, soil loss and water requirements of the cropping activities were directly derived from the EPIC-simulated results, taking into account unavoidable yield reductions due to climatic hazards (hail, frost and rainstorms), soil-borne diseases and pests, and crop management imperfections (fertilizers, weeding, biocides and irrigation may not always be timely and evenly applied), as well as land loss due to the building of terraces or hillside ditches to drain overland runoff. ...
... The defined production activities are futureorientated and generally have better resource use efficiency of nutrients, labor, water and land than the current production systems. They are, however, not unrealistic or infeasible since their input-output coefficients were similar to those found in experiments and pilot farms, as far as data were available for alternative production activities (Lu et al., 2003). Table 3 gives summery results of major input-output coefficients for all cropping activities on each of the land units. ...
Ansai is a county characterized by hilly loess relief that experiences all problems typical to the Loess Plateau of northern China, such as population pressure, soil loss, over-use of marginal lands, and poverty and food insecurity problems. Alleviation of these problems needs an integrated consideration of different objectives. To learn about the potentials and limitations of agricultural development and conflicts between objectives, this study conducted a systematic and trade-off analysis of different policy objectives, based on a land use optimization model (linear programming) integrating biophysical, agro-technical and socio-economic information. The results can serve two purposes, i.e., to reveal the solution space for each of the objectives and to analyze trade-off relationships between pairs of objectives. The information also forms the basis for further scenario analysis in which several objectives are considered simultaneously.
... Next, future-oriented production activities were defined that meet different objectives related to environmental protection, productivity , employment and income, taking into account land suitability and feasibility of agro-technologies and socio-economic conditions (Section 3.2). In the quantitative land evaluation, suitability of different physical environments (land units) was quantified for various land use systems under potential, water-limited and N-limited production situations (Lu et al., 2003). The quantitative information in combination with literature data and expert knowledge was then used for determination of the input–output coefficients of production activities (Section 3.3). ...
... Since this explorative land use study focused on food security and soil conservation , cropping activities were defined in detail, using a similar procedure as described by Hengsdijk and Van Ittersum (2002). Six design criteria were selected for the identification of cropping activities (Table 1), and four of the criteria were described by Lu et al. (2003), including the suitable land units, crop rotations, yield levelsTable 1 Design criteria and their variants for identification of cropping activities (production situations) and agro-techniques for water and soil conservation. Here, a description is only given of the remaining two criteria, mechanization levels and terracing options. ...
... Production activities were quantified using a 'target-oriented approach' (Van Ittersum and Rabbinge, 1997 ), in which the set of minimum inputs to realize a production target was calculated by assuming use of the 'best technical means'. Basic information for quantifying the production activities was obtained from results of the quantitative land evaluation (Lu, 2000; Lu et al., 2003) using the EPIC model (Mitchell et al., 1998) and from literature and expert knowledge. Target yields of cropping activities were based on the potential, water-limited and nutrient-limited yields simulated with EPIC, taking into account unavoidable yieldreductions due to climatic hazards (hail, frost and rainstorms), soil-borne diseases and pests (due to narrow rotations and particular cropping sequences), and crop management imperfections (fertilizers, weeding, biocides and irrigation may not always be timely and evenly applied).Table 2 presents summarized results of target yields for each of the eight crops, and the yields achieved in experiments and on relatively well-managed farms for comparison. ...
Soil loss, food insecurity, population pressure and low income of the rural population are interrelated problems in the Loess Plateau of northern China, and result in a spiral of unsustainability. This paper examines Ansai County as a case study to explore strategic land use options that may meet well-defined goals of regional development, using a systems approach that integrated the fragmented and empirical information on the biophysical, agronomic and socio-economic conditions. We used production ecological principles, simulation modeling and multiple goal linear programming as integrative tools. Four scenarios were explored, representing major directions of agricultural development in the region and views of national and local stakeholders, farmers and environmentalists. The results indicate that soil conservation, food self-sufficiency and income for the rural population can be substantially improved by efficient resource use and appropriate inputs. In the long-term, terracing and use of crop rotations with alfalfa may be the best options for soil conservation. The large rural population and the lack of off-farm employment opportunities could be the most important factors affecting rural development in Ansai. This study contributes to the understanding of regional problems and agricultural development potentials, and shows agro-technical possibilities for alleviating the unsustainability problems in this fragile and poorly endowed region. To promote actual development towards the identified options, on-farm innovation and appropriate policy measures are needed. The explored land use options enable a much more targeted innovation and development of policies.
... It covers 210.7 km 2 (0.1%) of the Loess Hills region, interlaced with hills, ravines, and plains, along with an average gully density of approximately 4.7 km km-2 (Xu, Tang, Zhang, & Yang, 2009). The soils, consisting of 60% to 70% silt, less than 15% clay, and less than 30% sand, have a high CaCO 3 content (approximately 9% to 14%) and a pH value above 8.0 (Lu, Van Ittersum, & Rabbinge, 2003). Annual precipitation ranges from 296.6 to 645.0 mm (mean 505.3 mm); annual temperatures vary from −23.6°C to 36.8°C (mean 8.8°C). ...
... Annual precipitation ranges from 296.6 to 645.0 mm (mean 505.3 mm); annual temperatures vary from −23.6°C to 36.8°C (mean 8.8°C). The rainy season is from July to September, accounting for nearly 74% of the total annual rainfall (Lu et al., 2003;Lu et al., 2004). The average household size is 4.3, with farming being the primary economic activity for 64.4% of the population (Ansai Statistical Bureau, 1999. ...
Payments for ecosystem services (PES) are often used as a tool for arresting land degradation and desertification. Nevertheless, deeper investigation of farm household systems (FHSs) changes during PES projects is rather limited. It is important to understand how various FHSs evolve with the divergent resource allocation strategies aiming at livelihood security in response to the PES scheme. Taking the Grain for Green Project (GGP) in China as an example, the intended and unintended consequences of a PES scheme on land management and conservation are analysed. Using principal component analysis and cluster analysis, FHSs types are identified, while composite indices regarding environmental, economic and food security are created to assess the livelihood security of each type. This is followed by a cost‐benefit analysis that investigates the multidimensional costs and benefits of FHSs types, as well as a regression analysis to explore the determinants of the livelihood security. The results show that seven distinct FHSs types evolved under the GGP PES scheme, with significant differences in livelihood security components. The strategy of setting aside the optimal share of land for ecosystem services, such as erosion reduction, and then compensating the economic loss with permanent and market‐oriented farming activities (greenhouse horticulture and orchards) can establish a positive link between economic development and environmental protection. Findings indicate that careful consideration of market, institutional, and policy interventions for supporting FHSs reorganisation under PES schemes are needed to align the environmental goals with food and economic security goals of farm households, ensuring sustainability of the benefits while limiting the unintended consequences.
... Most studies suggested that the EPIC model can calculate annual yield for an average yield of winter wheat under different irrigation and fertilization management systems [23,24], while numeral researchers report that EPIC models can simulate medium and average yield of winter wheat over a long period, but fail to reflect the changes of winter wheat yield between different years [18,19]. Results of EPIC model validation and application show that the EPIC model can simulate winter wheat yield in normal rainfall years in China [17,23,25]. Related research showed that the EPIC model has good adaptability for simulating crop yield and soil water change, not only on the Loess Plateau [17,23], but also at the North Plain of China [26][27][28]. ...
... This study shows that the EPIC model simulated soil water content well in 0-2.0 m soil, with an RRMSE value of 6.0-14.0%. A few related studies indicate that the EPIC model did not simulate soil water well in very dry and wet seasons [25,27]. Shallow soil water content, affected by precipitation and crop consumption, are particularly vulnerable to the effects of precipitation on dry land. ...
Understanding the influences of rainfall and temperature on soil water and the grain production of winter wheat (Triticum aestivum L.), is of great importance to ensure the sustainability of food production on the Loess Plateau of China. Based on calibration and evaluation, the Environmental Policy Integrated Climate (EPIC) model was employed to determine the response of soil water and winter wheat to rainfall and temperature changing over the last 30 years in different regions. Results showed that (1) the EPIC model simulated soil water content well in 0–2 m soil, with a relative root mean square error (RRMSE) value of 6.0~14.0%, and the mean value of R2 was 0.824, which was similar to the value of ME (0.815); (2) rainfall decreased 13.6–24.9% more from 2001 to 2010 than it did during 1961–2000, while its minimum and maximum temperature increased 1.00–1.55 °C and 0.30–0.84 °C respectively, in comparison with 1961–2000; (3) both the increase of maximum temperature and the decrease of rainfall were harmful to the production of winter wheat. Contrarily, the increase of minimum temperature was beneficial to the production of winter wheat on the Loess Plateau of China. Furthermore, due to rainfall decreasing, the winter wheat yield of Luochuan, Changwu, Yuncheng, and Yan’an decreased by 8.5%, 7.6%, 11.7%, and 12.3%, respectively. Because of the rising of the maximum temperature, winter wheat yield decreased 6.4%, 6.8%, 7.2%, and −3.0%, respectively. On the other hand, the increase of the minimum temperature raised the winter wheat yield of 8.8%, 10.2%, 1.5%, and 12.0%, respectively. Climate change, either precipitation reduction or temperature increase, decreased soil water in the dry land winter wheat field. Therefore, more water-saving technologies are needed to adapt to climate change, to store and use water sources more effectively in semi-arid regions. Though precipitation reduction and maximum temperature increase produced negative impacts on winter wheat yield, the uptrend in minimum temperature is better for increasing the winter wheat yield, which can be used by farmers and governments to adapt to climate change, by adjusting planting time properly.
... Ansai has typical characteristics of a semi-arid climate, such as annual precipitation ranging from 296.6 mm to 645.0 mm (mean 505.3 mm) and annual temperatures varying from À23.6°C to 36.8°C (mean 8.8°C). The rainy season is from July to September that accounts for nearly 74% of the total annual rainfall, and there is a small decline of 5%-10% from the south to north (Lu, Van Ittersum, & Rabbinge, 2003;Lu et al., 2004). The soils consist of 60%-70% silt and less than 15% clay and 30% sand and have a high content of CaCO 3 (approximately 9%-14%) and pH value above 8.0 (Lu et al., 2003). ...
... The rainy season is from July to September that accounts for nearly 74% of the total annual rainfall, and there is a small decline of 5%-10% from the south to north (Lu, Van Ittersum, & Rabbinge, 2003;Lu et al., 2004). The soils consist of 60%-70% silt and less than 15% clay and 30% sand and have a high content of CaCO 3 (approximately 9%-14%) and pH value above 8.0 (Lu et al., 2003). ...
Smallholder agriculture contributes to the rural economy of China’s Loess Plateau, and the Grain for Green project (GGP) is a land retirement policy causing land use change in smallholder agricultural systems (SASs). The article attempts to identify whether the GGP have positive or negative impacts on SAS in Ansai County, China’s Loess Plateau. Using official statistics from 1998 to 2009, we first revealed a SAS transformation toward specialized grain and potato production, intensive horticulture and orchards after 1998. Using survey data collected in 2010, a structural equation model (SEM) was developed to confirm the causal effects of the GGP on SAS in 2009 (the 3rd year after farmland retirement). Results showed that the GGP promoted the transformation of SAS and the improvement of household livelihood. Moreover, the GGP intervention of converting farmland and paying compensation gave opportunities to improve land use patterns and household livelihood but also provoked the loss of farmland and labor in SAS. For the sustainability of SAS in long term, commercial agriculture and farmers’ engagement and related skills might be enhanced along with continuing the prohibition of annual cropping and grazing on converted land.
... Hills, gullies and plains are interlaced, with an average gully density of 4.7 km/km 2 (Xu et al., 2009). The soils contain 60%-70% silt, around 15% clay and 30% sand, a high content of CaCO 3 (approximately 9%-14%) and pH value above 8.0 (Lu et al., 2003). The area has a semi-arid climate where annual precipitation ranges from 296.6 mm to 645.0 mm (mean 505.3 mm) and annual temperature varies from −23.6 • C to 36.8 • C (with a mean level of 8.8 • C) (Lu et al., 2003;Lu et al., 2004). ...
... The soils contain 60%-70% silt, around 15% clay and 30% sand, a high content of CaCO 3 (approximately 9%-14%) and pH value above 8.0 (Lu et al., 2003). The area has a semi-arid climate where annual precipitation ranges from 296.6 mm to 645.0 mm (mean 505.3 mm) and annual temperature varies from −23.6 • C to 36.8 • C (with a mean level of 8.8 • C) (Lu et al., 2003;Lu et al., 2004). The rainy season is from July to September, accounting for nearly 74% of total annual rainfall. ...
The article describes how economic resilience of farming households can be measured using a composite indicator of revealed adaptive actions, and investigates how capabilities of farm households to recombine human, financial, natural and physical capitals are linked to observed economic resilience to land set-aside interventions. The land set-aside intervention known as the Grain for Green Project (GGP), which has been altering livelihoods of farming households in China's Loess Hills since 1999, is taken as a case study. Household surveys were conducted in three V-shaped valleys and three riparian areas in Yanhe Township in northwestern China in an effort to measure household resilience and explore its' relationship to forms of capital. A composite index of adaptive strategies that can reorganize livelihood activities under land set-aside intervention into a new economic equilibrium is crafted using an objective weighting scheme based on principal component analysis. Subsequently, a multiple regression model was utilized to examine the relationship between the composite resilience index and various indicators related to human, social, financial, natural and physical capitals. The results reveal the latent structure and internal correlations of adaptive strategies, and present quantitative evidence about the relationship between livelihood capitals and household economic resilience. The analysis shows that household resilience deteriorates when the ratio of GGP land to cultivated farmland goes above a threshold level, and revealed that interventions targeting various forms of capitals can enhance the economic resilience for households to conservation efforts.
... The township covers 210.7 square kilometres (0.1%) of China's Loess Hills, which is a semi-arid area interlaced with hills, ravines and plains, and with an average gully density of 4.7 km/km 2 [27]. Annual precipitation ranges from 296.6 mm to 645.0 mm (mean 505.3 mm) with a short season from July to September; annual temperature varies from´23.6˝C to 36.8˝C (mean 8.8˝C) [5,28]. Additionally, 64.4% of the population take up farming as their primary economic activity [29], on land with soils containing 60% to 70% silt, around 15% clay and 30% sand [28]. ...
... Annual precipitation ranges from 296.6 mm to 645.0 mm (mean 505.3 mm) with a short season from July to September; annual temperature varies from´23.6˝C to 36.8˝C (mean 8.8˝C) [5,28]. Additionally, 64.4% of the population take up farming as their primary economic activity [29], on land with soils containing 60% to 70% silt, around 15% clay and 30% sand [28]. Per capita arable land is approximately 0.1 ha, which is close to the average area in China [30]; 44.3% of the arable land is used for open-field crops (e.g., potato, soybean, millet, corn, oilseed rape and sorghum), 30% for orchard crops (e.g., apples), 4.1% for horticulture crops (e.g., chilli, cabbage, cucumber, eggplant and carrot), and 0.6% for melons (e.g., watermelon and honey melon). ...
This article analyzes agricultural sustainability in the context of land degradation, rural poverty and social inequality, taking China's Loess Hills as an example. The analysis attempts to understand the multi-dimensionality of sustainability at the farm level and its relationship with physical-socio-economic-infrastructural-technological framework conditions in the context of the land set-aside program viz. the Grain for Green Project (GGP). We developed composite indices of sustainability and its environmental, economic and social dimensions using a principal component analysis (PCA)-based weighting scheme. Regression analyses were conducted to examine the relationship between the estimated sustainability indicators and the variables representing framework conditions of knowledge, demographics, resource endowment and production techniques. The stated analysis was conducted on a dataset collected by means of household surveys in 2014 in valleys and flood plain areas in Yanhe Township. Findings reveal hidden correlations among the indicators of environmental, economic, and social pillars of sustainability. The ratio of land under the conservation program to actual farmland emerged as a key determinant of overall agricultural sustainability and its social dimension, which reaches the maximum when the ratio is around 0.56 and 0.64, respectively. The results also show that there is need to balance off-farm and on-farm income diversification as well as highlight the role of women in ensuring the sustainability of farming households. The core achievement of the article is the definition of the thresholds for the land set-aside program and the identification of major determinants of agricultural sustainability in the rural Chinese context in particular and in rural farming communities in general.
... The township covers 210.7 square kilometres (0.1%) of China's Loess Hills, which is a semi-arid area interlaced with hills, ravines and plains, and with an average gully density of 4.7 km/km 2 [27]. Annual precipitation ranges from 296.6 mm to 645.0 mm (mean 505.3 mm) with a short season from July to September; annual temperature varies from´23.6˝C to 36.8˝C (mean 8.8˝C) [5,28]. Additionally, 64.4% of the population take up farming as their primary economic activity [29], on land with soils containing 60% to 70% silt, around 15% clay and 30% sand [28]. ...
... Annual precipitation ranges from 296.6 mm to 645.0 mm (mean 505.3 mm) with a short season from July to September; annual temperature varies from´23.6˝C to 36.8˝C (mean 8.8˝C) [5,28]. Additionally, 64.4% of the population take up farming as their primary economic activity [29], on land with soils containing 60% to 70% silt, around 15% clay and 30% sand [28]. Per capita arable land is approximately 0.1 ha, which is close to the average area in China [30]; 44.3% of the arable land is used for open-field crops (e.g., potato, soybean, millet, corn, oilseed rape and sorghum), 30% for orchard crops (e.g., apples), 4.1% for horticulture crops (e.g., chilli, cabbage, cucumber, eggplant and carrot), and 0.6% for melons (e.g., watermelon and honey melon). ...
This article analyzes agricultural sustainability in the context of land degradation, rural poverty and social inequality, taking China’s Loess Hills as an example. The analysis attempts to understand the multi-dimensionality of sustainability at the farm level and its relationship with physical-socio-economic-infrastructural-technological framework conditions in the context of the land set-aside program viz. the Grain for Green Project (GGP). We developed composite indices of sustainability and its environmental, economic and social dimensions using a principal component analysis (PCA)-based weighting scheme. Regression analyses were conducted to examine the relationship between the estimated sustainability indicators and the variables representing framework conditions of knowledge, demographics, resource endowment and production techniques. The stated analysis was conducted on a dataset collected by means of household surveys in 2014 in valleys and flood plain areas in Yanhe Township. Findings reveal hidden correlations among the indicators of environmental, economic, and social pillars of sustainability. The ratio of land under the conservation program to actual farmland emerged as a key determinant of overall agricultural sustainability and its social dimension, which reaches the maximum when the ratio is around 0.56 and 0.64, respectively. The results also show that there is need to balance off-farm and on-farm income diversification as well as highlight the role of women in ensuring the sustainability of farming households. The core achievement of the article is the definition of the thresholds for the land set-aside program and the identification of major determinants of agricultural sustainability in the rural Chinese context in particular and in rural farming communities in general.
... Farms in these two regions vary in their crop and livestock enterprises, and in the productivity of those enterprises. Working in eastern Gansu, Lu et al. (2003) indicated that ca. 30% of the arable area might be needed for subsistence grain production, close to the value (31%) obtained in the Dingxi survey, but lower than the 49% in the Qingyang farmer survey. ...
... One option for farmers to increase income is through increases in productivity. Although wheat yields in this region may be similar to comparable areas of the world (Sadras and Angus, 2006), there is good evidence that improved practices in the region can increase grain yields above those currently obtained (Huang et al., 2003;Lu et al., 2003). In Qingyang this is likely to result in considerable increases in farm income. ...
Gansu Province in north western China contains a large portion of China's rural poor. Within this province we compared extant farming systems in lower and higher rainfall areas of the Loess Plateau. The farming systems were dominated by subsistence winter wheat production in the higher rainfall more productive area (Qingyang), and subsistence spring wheat in the lower rainfall less productive area (Dingxi). Once household grain production is satisfied, remaining land is allocated to cash crop and livestock enterprises. Similar farm sizes (ca. 1 ha) in both areas meant that farmers in the more productive Qingyang area were easily able to meet household food needs and produce more cash income from sale of produce. They have reinvested this into their farms and are now developing new enterprises, particularly livestock and co-operative trading arrangements. This has allowed many of these farmers to move away from subsistence grain production, such that 72% of household income is now derived from sale of farm produce. However, many farmers in Qingyang indicated a lack of technical agronomic support and limited access to reliable markets as barriers to diversification. In Dingxi, many farmers struggle to grow sufficient grain for household use and generate very little cash income, often insufficient to provide basic needs such as education. Potatoes, pea and oilseeds are the most common cash crops here, but livestock enterprises are poorly developed. In this area only 28% of household income is generated on farm, and young males often leave the farm to work in larger cities, leaving farming decisions to the elderly, women, and children, who are left behind to manage the farm. High illiteracy rates in this group reduce assimilation of new information. Farmers in Dingxi indicated that restricted access to capital, lack of technical agronomic support and little access to trading markets were serious impediments to the development of more profitable enterprises.
... During testing, observations can be used to improve the estimation of parameters and new problems encountered contribute to changing assumptions made, thus initiating a new phase of designing and evaluation of alternatives. Other authors have developed tools to design and quantitatively evaluate land use systems (e.g., De Koning et al., 1995; Barbier and Bergeron, 1999; Hengsdijk et al., 1999; Lu et al., 2003 ). These tools are generally called Ôtechnical coefficient generatorsÕ (TCGs). ...
... Differently to Barbier and Bergeron (1999) and Hengsdijk et al. (1999) , in our approach we calculated technical coefficients at crop rotation scale, explicitly considering interactions among crops. Compared to De Koning et al. (1995) and Lu et al. (2003), we identified and quantified all possible rotations and not just an arbitrary selection. Other unique aspects of our approach are the quantification of soil erosion, rate of change of soil organic matter, nutrients balance and the environmental impact of pesticides, and it potential use as stand alone tool, even for the evaluation of options at farm scale. ...
Rapid changes in the social and economic environment in which agriculture is developing, together with the deterioration of the natural resource base threatens sustainability of farm systems in many areas of the world. For vegetable farms in South Uruguay, survival in the long term depends upon the development of production systems able to reduce soil erosion, maintain or improve physical and biological soil fertility, and increase farmer’s income to socially acceptable levels. We propose a model-based explorative land use study to support the re-orientation of vegetable production systems in South Uruguay. In this paper we present a new method to quantitatively integrate agricultural, environmental and socio-economic aspects of agricultural land use based on explicit design objectives. We describe the method followed to design and evaluate a wide variety of land use activities for Canelón Grande (South Uruguay) and we illustrate the usefulness of this approach in an ex-ante evaluation of new farming systems using data from 25 farms in this region. Land use activities resulted from systematic combination of crops and inter-crop activities into crop rotations, different crop management techniques (i.e., mechanisation, irrigation and crop protection) and animal production. We identified and quantified all possible rotations and estimated inputs and outputs at crop rotation scale, explicitly considering interactions among crops. Relevant inputs and outputs (i.e., soil erosion, balance of soil organic matter and nutrients, environmental impact of pesticides, labour and machinery requirements, and economic performance) of each land use activity were quantified using different quantitative methods and following the target-oriented approach. By applying the methodology presented in this paper we were able to design and evaluate 336,128 land use activities suitable for the different soil types in Canelón Grande and for farms with different availability of resources, i.e., land, labour, soil quality, capital and water for irrigation. After theoretical evaluation, a large subset of these land use activities showed promise for reducing soil erosion, maintaining soil organic matter content of the soil and increasing farmer’s income, allowing improvement of current farming systems in the region and providing a widely diverse set of strategic options for farmers in the region to choose from. This method can be used as a stand-alone tool to explore options at the field and farm scale or to generate input for optimisation models to explore options at the farm or regional scale.
... After achieving food sustenance for families, crop intensification/diversification becomes a mainstay for commercial agriculture. To reduce pressure on water resources, better-quality rainfed lands could be brought under either limited or unlimited irrigation during the post-rainy season (Lu 2003). The traditional farming systems are self-contained and show resilience to aberrant weather conditions, but are low yielders. ...
Arid and semi-arid regions cover more than 50% of the total geographical area in India which is highly populated, water-limited with warm drylands. There is an expectation that the area of drylands will expand under several scenarios of climate change. Maintaining food and nutritional security in this growing rural population of 265 million is a mammoth challenge in the near future. This task can be taken by diversifying the existing scarce resources in a sustainable manner as well as systematic land use management. Indian agriculture sector is dominated by marginal and small farm holdings. Production intensification or land diversification are the keys to agricultural sustainability. After achieving food sustenance for the family, crop intensification/ diversification becomes the mainstay for commercial agriculture. The traditional farming systems are self-contained and show resilience to aberrant weather conditions but yield poorly. An optimization of land usage into cropping, horticulture, livestock, forestry with an objective of food and nutritional security along with profitability holds the key for the future course of sustainable agriculture.
... Though both NL-L and L-L systems occupied the land nearly 63% of time in a year, maximum benefit-cost-ratio was observed with L-L system (4.0) followed by NL-L system (3.7) and lastly the rainfed L-F (2.9) with a rider on availability of irrigation water (Lu et al. 2003). ...
... Annual 369 precipitation ranges from 296.6 to 645.0 mm (mean 370 505.3 mm); annual temperatures vary from -23.6 to 371 36.8°C (mean 8.8°C) (Lu et al. 2003;Lu et al. 2004 The survey was conducted between February and May 398 2014 using a semi-structured questionnaire designed for 399 information on GGP PES, household demographics, the 400 availability and utilization of agro-ecological and socio-401 economic resources, and levels of household income and 402 consumption in 2013. We followed a three-stage stratified 403 sampling procedure. ...
In spite of positive expectations for environmental protection, payments for ecosystem services (PES) can bring about unintended disturbances to rural livelihoods. Based on resilience thinking, this article investigates livelihood resilience building at farm level through the interaction between farm adaptation and disturbances induced by China’s Grain for Green project (GGP). Cluster analysis was conducted to investigate the complexity and diversity of farm adaptation; the crafting of composite indexes was designed to value resilience through disturbance, sensitivity, and adaptability; regression analyses linked the resilience indexes and farm adaptation with access to resources. The results show three adaptation typologies (i.e. reclamation of retired lands, contractive farming, and expansive farming) with distinct land use structures and resilience scores, and highlight the need to improving farmers’ access and endowment of tangible (e.g. farming facilities) and intangible resources (e.g. skill training) for resilience-building practices in light of the GGP. The findings imply that policy interventions combining environmental restrictions with widening resource access to support alternative livelihoods can offset the unintended effects and amplify the success of PES programmes.
... Though both NL-L and L-L systems occupied the land nearly 63% of time in a year, maximum benefit-cost-ratio was observed with L-L system (4.0) followed by NL-L system (3.7) and lastly the rainfed L-F (2.9) with a rider on availability of irrigation water ( Lu et al. 2003). ...
Soil degradation in semi-arid regions is alarming due to changed climate impacting the rainfall patterns and temperature affecting soil physico-biological properties adversely. In India, cattle shed bedding technology (CSBT) using crop residues is cheaper, easy-to-use residue recycling method for small holders in semi-arid regions. The present research work was carried out with a specific objective of soil improvement leading to resilience of land use system using indigenously available fortified crop residue for enhanced crop and cropping system yields under both rainy and post rainy conditions in semi-arid tropics of India. Thus, a study was conducted for 2 years (2013–2014 and 2014–2015) in the farmers fields with treatments having various fortifications like bedding material with groundnut shell and its manure, compost over existing practice among farmers on rainfed groundnut-fallow (L-F), castor-groundnut (NL-L) and groundnut–groundnut (L–L) oilseed based cropping systems. These systems were evaluated for soil quality parameters, productivity, fertility, soil moisture retention, compaction, crop land utilization and economics. In different cropping systems, use of fortified groundnut shell @ 16.3–22.6 t ha⁻¹ year⁻¹ was able to recoup the soil nutrient losses (183.0 kg N, 6.1 kg P, 227.0 kg K and 0.3 kg OC ha⁻¹ year⁻¹) closely followed by compost and distantly by inorganics application with additional benefit of enhanced crop yields by 20.2–33.1% during subsequent rainy and 20.0–25.0% during post-rainy season, improved available water content (10.7–20.3%) and increased irrigation interval by 3–5 days in NL-L and L–L system. Hence, the principle of fortifying crop residues through CSBT could be utilized globally in similar agro-ecological regions for addressing soil degradation and effective crop residue utilization for small and marginal landholders farmers.
... Land use/cover changes cause conflicts in the value of the regional ecosystem services [36]. Reclaiming grasslands to farmland might increase the value of the ecosystem in the supply of agricultural products, but it might decrease its value in maintaining water and soil regulation and supporting services [37]. Agricultural working land plays an important role in conserving water sources and regulating climate, however, the surrounding ecosystems would compete with crops for water, sunlight, nutrients, and pollination, and would impact their functions in production [38]. ...
The purpose of this article is to analyze the effects of multifunctional rural land use (MRLU) on residents’ wellbeing. A questionnaire survey on 805 rural residents in 64 villages of the Xinzhou District of Wuhan city in China, and estimators of OLS, ordered logit, and ordered probit were employed. The Shannon’s H index and Simpson’s Reciprocal Index are used to measure MRLU and the life satisfaction approach is used to measure wellbeing. An inverted-U pattern is observed in the relationship between MRLU and wellbeing, and another finding of the study is the threshold of MRLU. The article contributes to the literature by integrating MRLU into wellbeing analysis from a spatial-separated form, and deepens the relationship between MRLU and the residents’ wellbeing. MRLU is characterized by differences and a moderation, which can provide a reference for profiling rural land use planning and for designing land-use policy, and for prompting rural sustainable development.
... The difference between potential and actual yields is referred to as the yield gap (Van lttersum and Rabbinge, 1997;Van Ittersum et al., 2013). This can also be expressed as the ratio of actual yield to potential yield, which illustrates how successful growers are in making best use of their environment and available resources to attain high yields (Lu et al., 2003). Actual:potential LUE ratios exceeded 60% for most regions (Table 4). ...
... More work must be done to provide evidence to farmers and policy makers to use the limited land and water more efficiently and to produce more food. For example, targetoriented analysis can be conducted for different land use criteria, e.g. to maximize grain production or economic profit, or to minimize environmental impact or labour input (van Ittersum et al., 1998;Lu et al., 2003;Lu et al., 2004;Dogliotti et al., 2005). Furthermore, land use analysis can be conducted in the regions where wheat-maize intercropping is feasible but not being used, to assess the potential increase in grain production if all or partly the current sole wheat and sole maize land is used for wheat-maize intercropping. ...
... Scientists attempted to use conservation tillage practices, rainfall harvesting and mulching technologies to improve water use and increase yield (Su et al., 2007;Wang et al., 2009). Rotation and intercropping were also conducted to raise the production (Lu et al., 2003;Xu et al., 2008). However, systematic and scientific forage management methods are still lacking, and forage options are very limited. ...
... The difference between potential and actual yields is referred to as the yield gap (Van lttersum and Rabbinge, 1997;Van Ittersum et al., 2013). This can also be expressed as the ratio of actual yield to potential yield, which illustrates how successful growers are in making best use of their environment and available resources to attain high yields (Lu et al., 2003). Actual:potential LUE ratios exceeded 60% for most regions (Table 4). ...
... The soil pH is more than 8.0 with a high content of CaCO 3 (mostly 9-14%) over the whole soil depth. In the floodplains, the soils have a relatively coarser texture, higher soil fertility and lower content of CaCO 3 (Lu et al., 2003). The zonal vegetation is forest-shrub-steppe, due to long-term human activities, most of the natural vegetation has been removed. ...
... Simulation models may not provide as precise an answer as field experiments, but they are much less costly and can procure satisfactory results as long as the input values and the processes modelled are typical of the field conditions. Simulation models have been used in the Loess Plateau to define alternative agricultural practices (Wu et al. 1996;Lu et al. 2003), but it seems that none have been validated. ...
The Erosion and Productivity Impact Calculator (EPIC) has been used to determine the effect of different cropping systems and management practices on soil productivity in the Loess Plateau of China. However, its crop growth and soil water balance submodels have not been verified in this region. The objective of the present study was to evaluate the ability of EPIC to estimate soil water content (94) were used to optimize the four most sensitive parameters of the EPIC crop yield submodel, whereas data from 1994 to 2004 were used for validation. For both crops, there were no significant differences between measured and estimated long-term means of the three variables (P=0·05) for either the calibration or validation periods. EPIC estimated all three variables with a small relative root mean square error (RRMSE), i.e. the ratio of root mean square error to the mean value. For wheat and maize, the calibration period resulted in respective RRMSE values of 0·112 and 0·100 for , 0·129 and 0·135 for ET, and 0·169 and 0·149 for Y, for wheat and maize, respectively. The performance of EPIC in estimating annual values of , ET and Y, respectively, for wheat, and 60, 70 and 67% for maize. The EPIC-estimated long-term average values of the three variables were not significantly different from measured values for winter wheat and maize during the calibration and validation periods. It can therefore be used in the gully region of the Loess Plateau to define alternative cropping systems and management practices.
... EPIC is a simulation model validated and widely used in the USA and in many other countries in the world (Gassman et al., 2005). It has also been tested and used in China for simulating yield and water consumption of different crops (Lu et al., 2003; Liu, 2007; Wang and Li, 2009), wind erosion (Wang et al., 2002), soil organic carbon dynamics (Li et al., 2003; Thomson et al., 2006) and the effects of climate change on crop yields (Chavas et al., 2009). EPIC consists of nine sub-models to simulate major biophysical processes including plant growth and crop yield, nutrient cycling, soil temperature, hydrology, water and wind erosion, and crop and soil management (Williams et al., 1990). ...
The North China Plain (NCP) is the most important wheat production area in China, producing about two-thirds of China's total wheat output. To meet the associated increase in China's food demand with the expected growth in its already large population of 1.3 billion and diet changes, wheat production in the NCP needs to increase. Because of the farmland reduction due to urbanization, strategies for increasing wheat production in the NCP should be targeted at increasing current yields. To identify options for increasing wheat yields, we analyzed the yield potentials and yield gaps using the EPIC (Environment Policy Integrated Climate) model, Kriging interpolation techniques, GIS and average farm yields at county level. As most (ca. 82%) of the winter wheat in the NCP is irrigated, it is justified to use potential yield as the benchmark of the yield gap assessment. Wheat potential yields simulated with EPIC using daily weather data from 1960 to 2007 at 43 representative sites varied from 6.6 to 9.1 t ha−1 in the NCP, generally increasing from north to south associated with decreasing low temperature stress. Based on the county-level data (2004–2007), the actual wheat yield varied between 2.4 and 7.7 t ha−1, while the yield gap was between 0.6 and 5.3 t ha−1 (7–69% of the potential yield) across the NCP and decreased with increase of actual yields (R2 = 0.82). For the entire region, the weighted average actual yield was 5.7 t ha−1, while the yield gap was 2.7 t ha−1 or 32% of the potential yield. Using 80% of the potential yield as an exploitable level, the average actual wheat yield in the NCP could be increased by 1.0 t ha−1 or 18%. The results provide an indication of the possibilities to increase wheat yields in the NCP.
... Annual precipitation in the region ranges from 200 to 750 mm, with 70% falling between June and September, often in the form of heavy thunderstorms (Li, 2000). This has increased the severity of soil erosion, as indicated by a rate of soil loss that is generally more than 50 t ha −1 in hilly areas (Lu et al., 2003). Since the beginning of the 20th century, and particularly during the last several decades, the human population has increased significantly, leading to a rapid decline in arable land in the region. ...
Reconfiguration of hillside fields into terraces is a key technique for water and soil conservation in mountainous regions. In this study, the effects of adding manure on soil water status and crop yields in newly-built terraces in 7 growing seasons on the semi-arid Loess Plateau of China were evaluated. Experimental treatments including CK (control treatment with no fertilizer), NP (nitrogen and phosphorus), M (manure), and MNP (manure, nitrogen and phosphorus) were employed with a field pea-spring wheat-potato cropping system. Manure groups are better able to conserve soil water, average soil water content in the 0–100 cm soil profile in the 5 years prior to sowing was over 42.2 mm in the MNP group than in the NP group, and 23.2 mm higher in the M group than in the CK group. After 7 years, soil water in the upper 200 cm of soil in the MNP and M groups was kept in balance, while significant soil water depletion reached the 140 cm soil layer in the CK and NP groups when compared to their values before sowing in 2004. Manure management significantly increased soil water stable macro-aggregates (>0.25 mm) compared to groups without manure in the 0–20 and 20–40 cm soil layers. Average yield over the 7 years was higher in the MNP group than in the CK, NP and M groups by 212%, 54% and 82%, respectively, and average water use efficiency (WUE) was higher by 207%, 51% and 77%, respectively. In the long run, treatment with inorganic fertilizer (NP) alone may not be sufficient to maintain high yields due to soil water depletion year after year. Farmers should be encouraged to apply manure to maintain the sustainability of agro-ecosystems in newly-built terraces in semi-arid areas.
... Arable cultivation on slope-lands accounts for 50% of total cropland of the Loess Plateau region and up to 70% in the Loess hilly areas (Tang et al., 1998). Cultivation of slope-lands is associated with serious soil and water loss (Shi & Shao, 2000), with a rate of soil loss of over 50 t Á ha À1 Á a À1 (Lu et al., 2003). Lower reaches of the Yellow River Basin receive sediment load of around 1.6 billion tons per annum and most of this sediment originates from the Loess Plateau (Ritsema, 2003). ...
Vegetation succession depends on the availability of suitable propagules in the soils, and an understanding of soil seed banks is important for effective vegetation restoration of abandoned croplands. Aims of this study were to identify characteristics of soil seed bank, relationship with standing vegetation, and potential significance of soil seed bank for vegetation restoration in abandoned croplands on the hilly-gullied Loess Plateau. Results of field survey, germination, and correspondence analysis showed that density of soil seed bank ranged from almost 900 through almost 6470 seeds m at 0–5 cm depth and almost 120 through almost 2470 seeds m at 5–10 cm depth, with species richness of 7–14. Early successional species dominated soil seed bank, while later successional species occurred only at low densities. Similarity between soil seed bank and standing vegetation was low (with an average of 0.261). Most important variables contributing to the variation of the standing vegetaion included soil water, extractable P, soil seed bank density, and aspect. Soil seed bank alone explained 32% of vegetation community variation. Potential for vegetation restoration from soil seed banks is limited, and it is recommended to transplant some later successional species into abandoned croplands to accelerate succession.
... Arable cultivation on slope lands accounts for 50% of the total cropland of the Loess Plateau region and up to 70% of cropland in the Loess hilly areas (Tang et al. 1998). Cultivation of slope lands is associated with serious soil and water loss (Shi & Shao 2000), with a rate of soil loss of more than 50 t/ha (Lu et al. 2003). The lower reaches of the Yellow River basin receives a sediment load of around 1.6 billion tons per annum, and most of this sediment originates from the Loess Plateau (Ritsema 2003). ...
In the Loess Plateau, China, arable cultivation of slope lands is common and associated with serious soil erosion. Planting trees or grass may control erosion, but planted species may consume more soil water and can threaten long-term ecosystem sustainability. Natural vegetation succession is an alternative ecological solution to restore degraded land, but there is a time cost, given that the establishment of natural vegetation, adequate to prevent soil erosion, is a longer process than planting. The aims of this study were to identify the environmental factors controlling the type of vegetation established on abandoned cropland and to identify candidate species that might be sown soon after abandonment to accelerate vegetation succession and establishment of natural vegetation to prevent soil erosion. A field survey of thirty-three 2 × 2–m plots was carried out in July 2003, recording age since abandonment, vegetation cover, and frequency of species together with major environmental and soil variables. Data were analyzed using correspondence analysis, classification tree analysis, and species response curves. Four vegetation types were identified and the data analysis confirmed the importance of time since abandonment, total P, and soil water in controlling the type of vegetation established. Among the dominant species in the three late-successional vegetation types, the most appropriate candidates for accelerating and directing vegetation succession were King Ranch bluestem (Bothriochloa ischaemum) and Lespedeza davurica (Leguminosae). These species possess combinations of the following characteristics: tolerance of low water and nutrient availability, fibrous root system and strong lateral vegetative spread, and a persistent seed bank.
... Considering the actual agricultural situation in China (Lin, 1998;Lüth and Preusse, 2007) -production as well as markets -intercropping as a well-adapted cropping system in this country is an option to solve the massive environmental problems caused by high use of fossilenergy-based inputs and a non-resource-preserving agriculture. Hence, a traditional cropping system could turn out to be a modern one (Lu et al., 2003;Zhen et al., 2005). ...
Intercropping has a 1000-year old history in Chinese agriculture and is still widespread in modern Chinese agriculture. Nowadays,
agricultural systems in China are stigmatized to exhaust high levels of input factors like N fertilizer or irrigation water
and to contribute severely to environmental problems like desertification, river eutrophication, soil degradation and greenhouse
effect. In this context, monocropping systems have to be revised and may not be the best performing systems any more, considering
sustainability, income security and nutritional diversity in rural areas. Therefore, intercropping systems offer alternatives
for a more sustainable agriculture with reduced input and stabilized yield. Especially in the last decade this cropping system
has been rediscovered by scientific research. Studies showed increased yield of maize and wheat intercropped with legumes:
chickpea facilitates P uptake by associated wheat, maize intercropped with peanut improves iron nutrition and faba bean enhances
N uptake when intercropped with maize. China’s intercropping area is the largest in the world. Nevertheless, there are only
few international studies dealing with intercropping distribution, patterns and crops. Most studies deal with nutrient-use
efficiency and availability. This study is a first approach to gain an overview of intercropping history, basic factors about
interspecific facilitation and competition and distribution of Chinese intercropping systems. Finally, four intercropping
regions can be distinguished and are explicitly described with their intercropping intensity, potential and conditions.
KeywordsArable crops-China-Intercropping-Sustainable agriculture
... Arable farming, with poor soil and crop manage- ment, has been widely practiced in this area, resulting in serious soil degradation and erosion. The rate of soil loss is generally more than 50 t/ha in upland areas ( Lu et al., 2003). Since 1990s, crop yields in the semiarid Loess Plateau have greatly increased due to the use of new technology, including a g r i c u l t u r a l w a t e r m a n a g e m e n t 9 5 ( 2 0 0 8 ) 1 9 0 -1 9 8 a r t i c l e i n f o ...
The alfalfa pastureland in the semiarid Loess Plateau region of Northwest China usually has dry soil layers. A field experiment was conducted from October 2000 to October 2004 to examine soil water recovery and crop productivity on a 9-year-old alfalfa pasture. This experiment included six treatments: alfalfa pasture for 10–14 years, a conventional farming system without prior alfalfa planting, and four alfalfa–crop rotation treatments. For the rotation treatments, after 9 years of alfalfa selected crops were planted from 2001 to 2004 in the following sequence: (1) millet, spring wheat, potatoes, peas; (2) millet, corn, corn, spring wheat; (3) millet, potatoes, spring wheat, corn; (4) millet, fallow, peas, potatoes. The results showed that dry soil layers occurred in alfalfa pasture. We then plowed the alfalfa pasture and planted different crops. The soil water gradually increased during crop growth in the experimental period. The degree of soil water recovery in the four alfalfa–crop rotation treatments was derived from comparison with the soil water in the conventional system. After 4 years, the soil water recovery from the alfalfa–crop rotation systems at 0–500 cm soil depth was 90.5%, 89.8%, 92.2% and 96.7%, respectively. Soil total N content and soil respiration rate were high in the alfalfa–crop rotation systems. The yields of spring wheat in 2002, peas in 2003 and potatoes in 2004 in the alfalfa–crop rotation systems were not significantly different from yields in the conventional system. In the alfalfa–crop rotation systems, the yields of spring wheat and peas were greatly influenced by rainfall and were lowest in the dry year of 2004; the yields of corn and potatoes had a direct relationship with water use and were lowest in 2003. In summary, soil water in dry soil layers can recover, and crop yields in the alfalfa–crop systems were equal to those of the conventional system.
... A quarter of the sediment load was deposited in the channel and the riverbed is continuously aggrading, leading to the formation of a perched river with its riverbed elevated 3-10 m above the neighbouring plains (Li and Finlayson, 1993), and creating potential flooding disasters along the lower reaches of the Yellow River Basin. The cultivated slope land, which accounts for up to 70% of arable land in the loess hilly and gully areas (Tang et al., 1998), is a major factor associated with serious soil and water loss (Shi and Shao, 2000), with the rate of soil loss exceeding 50 t ha −1 year −1 (Lu et al., 2003). In places on the Loess Plateau, where human activity has completely destroyed the original vegetation, conversion to natural vegetation could be the best strategy for eco-environmental rehabilitation (Zheng, 2006;Li and Shao, 2006). ...
A study was conducted in the forest-steppe region of the Loess Plateau to provide insight into the factors affecting the process of vegetation establishment, and to provide recommendations for the selection of indigenous species in order to speed up the succession process and to allow the establishment of vegetation more resistant to soil erosion. Four distinctive vegetation types were identified, and their distribution was affected not only by the time since abandonment but also by other environmental factors, mainly soil water and total P in the upper soil layers. One of the vegetation types, dominated by Artemisia scoparia, formed the early successional stage after abandonment while the other three types formed later successional stages with their distribution determined by the soil water content and total P. It can be concluded that the selection of appropriate species for introduction to accelerate succession should be determined by the local conditions and especially the total P concentration and soil water content.
... Humans currently face serious environmental challenges at global and local scales, and ecological security has become equally important with military security, economic security, political security and national security, etc. in recent years (Andersen and Lorch, 1998;Hormuth, 1999;Glenn et al., 1999;Kullenberg, 2002;Ianchovichina et al., 2001;Duffy et al., 2001;Albers and Goldbach, 2000;Brummett and Williams, 2000;Luijten et al., 2001;Shi et al., 2005;Soffer, 2000;Farmer, 2005;Bonheur and Lane, 2002;Moseley, 2001;Singh, 2000;Lu et al., 2003). At present, most assessing methods of ecological security are to choose biological and physical and chemic characteristics which are sensitive to the changes of ecological environment as indicators and monitor their reflection changes to ecological environment so as to judge whether ecology is security or not (Yang and Lu, 2002;Godoy et al., 2001;Pantelimon, 1999;Xiao et al., 2002;Zuo et al., 2002;Guan, 1998). ...
This article is an elementary exploration and practice of applying the theory and method of ecological footprint to assess regional ecological security. The ecological footprint from 1986 to 2002 and ecological security of three regions of Shaanxi Province of China were calculated and analyzed based on the theory of ecological footprint. Furthermore, the concept and model of ecological footprint pressure index (EFPI) as well as the grade system of regional ecological security was put forward based on ecological footprint so as to analyze the regional ecological security, and some measures to slow down the growth of the ecological footprint and maintain the regional ecological security were put forward at last. The following results were obtained. (1) It is feasible to analyze regional ecological security based on EFPI, which can reflect the degree of ecological security from two respects of carrying capacity and pressure. (2) Among 16 years from 1986 to 2002, the per capita ecological capacity in three regions appears to be a reducing tendency, the per capita ecological footprint shows an increasing tendency, the south of Shaanxi Province (SSP) is 12.02 times of the north of Shaanxi Province (NSP) in the per capita ecological surplus. The per capita ecological deficit appears in the middle of Shaanxi Province (MSP). (3) Based on ecological footprint, ecological capacity from 1986 to 2002 in the three regions, the average EFPI in the three regions were calculated, the EFPI of NSP is 0.8653, MSP is 1.1291 and SSP is 0.2103. According to the ecological security grade system measured off by EFPI and the average EFPI in the three regions, and considering the pressure human imposed on nature, the sequencing of the security degrees of three major regions is: SSP > NSP > MSP.
... Cavero et al., 1998;Chung et al., 1999;Izaurralde et al., 2003;Legler et al., 1999), Canada (e.g. Puurveen et al., 1997;Roloff et al., 1998), Italy (Rinaldi, 2001), Argentina (Bernardos et al., 2001), Great Britain (Boardman and Favis-Mortlock, 1993), India (Priya and Shibasaki, 2001), and China (Lu et al., 2003). ...
Increasing atmospheric greenhouse gas concentrations are expected to induce significant climate change over the next century and beyond, but the impacts on society remain highly uncertain. This work examines potential climate change impacts on the productivity of five major crops in eastern China: canola, corn, potato, rice, and winter wheat. In addition to determining domain-wide trends, the objective is to identify vulnerable and emergent regions under future climate conditions, defined as having a greater than 10% decrease and increase in productivity, respectively. Data from the ICTP RegCM3 regional climate model for baseline (1961–1990) and future (2071–2100) periods under A2 scenario conditions are used as input for the EPIC agro-ecosystem simulation model in the domain [30°N, 108°E] to [42°N, 123°E]. Simulations are performed with and without the enhanced CO2-fertilization effect. Results indicate that aggregate potential productivity (i.e. if the crop is grown everywhere) increases 6.5% for rice, 8.3% for canola, 18.6% for corn, 22.9% for potato, and 24.9% for winter wheat, although with significant spatial variability for each crop. However, without the enhanced CO2-fertilization effect, potential productivity declines in all cases ranging from 2.5 to 12%. Interannual yield variability remains constant or declines in all cases except rice. Climate variables are found to be more significant drivers of simulated yield changes than changes in soil properties, except in the case of potato production in the northwest where the effects of wind erosion are more significant. Overall, in the future period corn and winter wheat benefit significantly in the North China Plain, rice remains dominant in the southeast and emerges in the northeast, potato and corn yields become viable in the northwest, and potato yields suffer in the southwest with no other crop emerging as a clear beneficiary from among those simulated in this study.
... They found a high variation of yield for single years (r = 0.63 for wheat, 0.71 for maize and 0.25 for sunflower), but a satisfying calculation of the long-term trend and a good agreement for singular erosion events like the dust storms in the years from 1930 to 1940. In a similar study Lu et al. (2003) tried successfully to find efficient cropping systems in the Loess Plateau in China. A recent study from West Africa (Adejuwon, 2004) has compared yield of rice, sorghum and maize with the results from EPIC simulations. ...
Land-use is a key factor in hydrological modelling. It controls not only parameters such as evaporation and runoff from catchments, but also erosion and water quality. This review summarizes the different approaches to integrate land-use in mesoscale catchment models and simulation projects. After a short overview of the basic possibilities to include land-use in hydrologic models, we discuss the implementation of land-use in selected models. The main part of the paper deals with different approaches to link land-use and water cycle. The papers which have been analysed in our review are classified into three categories: analysis of consequences of land-use changes on water cycle, scenarios with a fixed land-use and optimization of land-use according to economic or ecologic criteria. We finish with an outlook on the technical development of integrated modelling.
... Examples of EPIC applications include plot-or field-level assessments of sediment, nutrient, and/or pesticide 1 Formerly Texas Agriculture Experiment Station. 2 Originally known as the Erosion Productivity Impact Calculator. loss as a function of different cropping or management systems (Jackson et al., 1994; Chung et al., 2002; Lu et al., 2003; Wang et al., 2006b), field-level crop yield, nitrogen cycling, or soil carbon sequestration evaluations (Williams et al., 1989; Cabelguenne et al., 1990; Cavero et al., 1999; Wang et al., 2005; Izaurralde et al., 2006), regional-level assessments of nitrogen leaching, soil carbon sequestration, or other environmental indicators (Wu and Babcock, 1999; Cepuder and Shukla, 2002; Gaiser et al., 2008) including interfaces with economic analyses (Feng et al. 2005;), and global assessments of crop yield as a function of climate change, land use change, or water management (Tan and Shibaski, 2003; Liu et al., 2007). SWAT applications range from hydrologic and/or pollutant loss validation studies (Arnold et al., 2000; Saleh et al., 2000; Jha et al., 2007; Reungsang et al., 2007; Green and van Griensven, 2008; Stehr et al., 2008), to hydrologic assessments of climate change, reservoir, wetland, or tile drainage effects, or land use change across a variety of watershed scales (Jha et al., 2006; Gosain et al., 2006; Green et al., 2006; Wu and Johnston, 2007; Jones et al., 2008; Wang et al., 2008e; Cao et al., 2008), to best management practice (BMP), land use, and other scenario analyses on pollutant losses (Nelson et al., 2005; Secchi et al., 2007; Volk et al., 2008; Ghebremichael et al., 2008; Parajuli et al., 2008), to hydrologic balance, climate change or other analyses of huge river basins or water resource systems at the national, subcontinent, or entire continent scale (Arnold et al., 1999; Thomson et al., 2003; Schuol et al., 2008a,b). ...
The Agricultural Policy Environmental eXtender (APEX) model was developed by the Blacklands Research and Extension Center in Temple, Texas. APEX is a flexible and dynamic tool that is capable of simulating a wide array of management practices, cropping systems, and other land use across a broad range of agricultural landscapes, including whole farms and small watersheds. The model can be configured for novel land management strategies, such as filter strip impacts on pollutant losses from upslope cropfields, intensive rotational grazing scenarios depicting movement of cows between paddocks, vegetated grassed waterways in combination with filter strip impacts, and land application of manure removal from livestock feedlots or waste storage ponds. A description of the APEX model is provided, including an overview of all the major components in the model. Applications of the model are then reviewed, starting with livestock manure and other management scenarios performed for Livestock and the Environment: A National Pilot Project (NPP), and then continuing with feedlot, pesticide, forestry, buffer strip, conservation practice, and other management or land use scenarios performed at the plot, field, watershed, or regional scale. The application descriptions include a summary of calibration and/or validation results obtained for the different NPP assessments as well as for other APEX simulation studies. Available APEX Geographic Information System–based or Windows-based interfaces are also described, as are forthcoming future improvements and additional research needs for the model.
... Generally, the water balance has been roughly calculated on the basis of mass balance, ignoring runoff or deep percolation because of the difficulties associated with measuring these variables (Yunusa et al., 1994;Sharma et al., 1998;Huang et al., 2005). Several studies in the Loess Plateau have been more concerned with the effects of soil management and cropping systems on crop yield and water use efficiency than on the complete water balance (Li et al., 2000;Lu et al., 2003;Fan et al., 2005;Huang et al., 2005). Therefore, quantitative analyses of the partitioning of water balance components under various soil management practices are needed. ...
Water is the most limited factor for crop production in dryland farming. In the work underlying this thesis soil hydraulic properties and water balance under various soil management regimes in the Chinese Loess Plateau were evaluated in laboratory studies, field experiments and simulations. Several methods for measuring soil hydraulic properties were also tested. The study was carried out at three sites on the Loess Plateau: Mizhi in the northern part, Heyang in the southeast and Yangling at the southern edge of the plateau.
The saturated hydraulic conductivity of the loess soil at these sites was similar. However, the unsaturated hydraulic conductivity, K(), of the soil was higher at the northern site (Mizhi) than at the southern sites (Heyang and Yangling), and soil water retention showed the opposite pattern. Laboratory studies demonstrated that soil compaction significantly influenced soil hydraulic properties, reducing the saturated hydraulic conductivity and altering the shape of the soil water retention curves at two of the sites (Mizhi and Heyang). At the Yangling site long-term application of organic manure increased water retention in the low tension range and decreased the unsaturated hydraulic conductivity, K(), at relatively high water contents in the surface layer (0-5 cm). However, it did not affect the saturated hydraulic conductivity. These, and other, effects of soil management practices on the soils’ hydraulic properties alter the partitioning of the water balance. To assess these effects in a winter wheat system, an integrated ecosystem model was calibrated using the results of a three-year field experiment, and a long-term (45-year) simulation was run to evaluate the sustainability of wheat production under various soil management regimes. The simulations showed that mulching optimized the partitioning of the water balance components, decreasing soil evaporation and increasing both transpiration and deep percolation, leading to increased wheat yields and WUE. Furthermore, mulching significantly improved the quantity and frequency of deep percolation, which should enhance the groundwater recharge potential. Incorporating mulching into the winter wheat-summer fallow system could be a sustainable management strategy for the Loess Plateau. Increasing the organic matter content of the soil could be another beneficial approach, if sufficient resources were available. Soil compaction caused the most unfavourable partitioning of water balance, leading to the lowest yield and WUE of all the treatments. Considering all of the factors involved, the duration of bare fallow should not be less than 30 days to maximise the benefits of producing green manure or fodder without significantly reducing the wheat yield and WUE.
... Model based land use studies have been proposed and used to support strategic thinking during the design of new farming systems in different regions of the world (Rossing et al., 1997;Zander and Kächele, 1999;Ten Berge et al., 2000;Lu et al., 2003;Mazzeto and Bonnera, 2003;Castelán-Ortega et al., 2003;Keating et al., 2003;Van Ittersum et al., 2003;Pacini et al., 2003). This type of studies may contribute to cropping or farming systems development by presenting a quantified set of alternatives that result from different priorities for sustainability objectives, thus revealing consequences of following different development pathways. ...
In different parts of the world, there is an urgent need for redesigning and innovating farming systems. Such a process may be supported by model-based explorations that enable ex-ante evaluation of a broad range of alternatives. Since a variety of viable patterns of farm development exists related to farm resource endowment and farmer's strategy, model-based explorations should be able to capture the existing variation in resource endowment and strategies in order to have impact on strategic farm management. In this paper, we present an overview of the model-based explorative method based on the MILP model Farm Images, applied to explore options for sustainable development of vegetable farms in Canelón Grande, Uruguay. The method is used to gain insight into the impact of current farm resource endowment on the possibilities for sustainable development and on the resource use efficiency at farm scale. We maximized farm income for 128 different farm types in an environment-oriented scenario and in an income-oriented scenario. Farm types were defined by combining 4 farm sizes, 2 labor endowments, 4 irrigation endowments, 2 soil quality combinations and 2 mechanization levels. The results demonstrate a strong impact of farm resource endowment on possibilities for sustainable development, as well as synergy between labor, land and irrigated area on resource-use efficiency at farm scale. Farms with 10ha of land or less, representing 47% of the farms in the Canelón Grande region, could only achieve a family income higher than the average income of Uruguayan families when the irrigated area was ca. 40% of the farm area. The achievement of environmental targets was less costly in terms of income on farms with a low rather than high labor availability per unit area and on farms with irrigation facilities.
Human activity and climate change are degrading the environmentally fragile Loess Plateau in dry and semiarid regions. Land deterioration threatens human and ecological existence. To prevent additional land degradation and ensure the ecological development and quality of arable land in the region, China launched “Grain for Green” in the late 1990s. This effort greatly boosted Loess Plateau vegetation. However, land degradation is complex, and so we must also examine natural and social variables to prevent additional degradation. Thus, this study presents a comprehensive index system to quantify land degradation on the Loess Plateau and uses machine learning to anticipate high‐risk locations. The project improved land degradation, and the spatial distribution of degradation risk is high in the northern and low in the eastern and southern regions of the Plateau. Gross Domestic Product and population density are the main drivers of land degradation. Industrialization and urbanization have raised the risk of land degradation, which now accounts for 1%–2% of the area. This study emphasizes sustainable land management in the Loess Plateau, a critical area for sustainable development in China. The integrated assessment indicator system and random forest modeling machine learning help grasp the current status and future preventive measures. The outcome of this study advances the Loess Plateau land degradation research and sustainable land management. The research findings possess significant scientific reference value in terms of mitigating and managing land degradation in environmentally vulnerable regions worldwide.
Terraces are a popular and widely-distributed engineered agricultural landscape in mountainous regions. In this study, the effects of adding manure on soil organic C (SOC) sequestration, soil aggregate distribution, C/N ratio and activities of enzyme were evaluated in newly-built terraces over 7 growing seasons from 2004 to 2010 on the semi-arid Loess Plateau of China.
New cropping alternatives are explored in response to the drawbacks of the Green Revolution. Alternative practices use the ecological regulations of agroecosystems, and strengthen and manage agricultural biodiversity. Multi-species cropping systems are good models to seek innovative solutions. Indeed the combination of crops, ranging from simplest forms to complex multi-stage associations, such as agroforests, have allowed many populations to maintain their production conditions, while at the same time overcoming severe shocks such as droughts, epidemics or changes in market prices. An empirical agroecology has thus been created mainly using traditional knowledge. We present the following benefits provided by the ecosystem services of mixed cropping: (1) yields are often higher than in monocultures, (2) the amount of mineral and organic fertilizers is decreased two times, (3) mixed cropping is an effective alternative to pesticides, (4) water and energy is saved, (5) soil quality is preserved, and (6) worktime is better managed. A true agroecological engineering approach, linking scientific and empirical knowledge can thus be designed.
Ecological security defined as the creation of a condition where the physical surroundings of a community provide for the needs of its inhabitants without diminishing its natural stock, which is important for regional security and social stability. In recent years, land use patterns in the Changbai Mountain region have changed significantly with intensive human activities, and consequently led to increasing problems in regional ecological security. Based on the Pressure-State-Impact-Response (PSIR) model and the mathematical method of catastrophe progression supported by geographical information system (GIS), the ecological security situation of the study area under land use and cover change (LUCC) was evaluated. The results indicated that the ecological security in Changbai Mountain region varied nonlinearly, which got better from 1990 to 2000 but became worse from 2000 to 2007, the ecological security levels in Changbai Mountain region were mainly medium and medium to low during the past 17 years, with higher values of Ecological Security Index (ESI) in the central region and lower values in the east and west, the ecological security situation was more serious in the settlements and river valleys, where the LUCC was most remarkable.
The management of water and nutrients in farming systems that incorporate alternating phases of lucerne pasture with annual grain crops posses additional challenges to rotations with annual crops only. Strategies for balancing water and nutrient resources within and across rotations will be governed by local soil, climatic, skill and economic constraints. On the Loess Plateau in China, farmers have been encouraged to grow lucerne (Medicago sativa) to reduce soil erosion and improve soil fertility on cropping lands but with little supporting information on how to incorporate lucerne within subsistence cropping systems. Lucerne–wheat rotation experiments were established at two locations in Gansu Province and examined the yield of lucerne and wheat along with changes in soil water and nitrogen (N). Lucerne proved to be well adapted to the high water holding capacity soils and summer dominant rainfall environment of the region with annual production of around 12 t ha−1 at the higher rainfall site (Qingyang). An old (30 years), sparse stand of lucerne growing in the drier location (Dingxi) was much less productive, being dependent on incident rainfall. Apparent water use efficiency (WUE) of lucerne over individual harvest periods ranged from 4 to 56 kg ha−1 mm−1 at Qingyang. Lucerne was able to dry the soil to the crop lower limit (CLL) to depths of 3 m and there was clear evidence that lucerne roots were extracting water below this depth.
This paper describes the current situation of China’s land use and land use changes, major driving forces, and their impacts
on the environment, through a review on land use studies in the past decades in China.
Crop potential productivity is a key index of scientifically appraising crop production and land population-supporting capacity.
This study firstly simulated the potential and waterlimited yield of summer maize in the Beijing-Tianjin-Hebei (BTH) region
using WOFOST model with meteorological data of 40 years, and then analyzed yield gaps between the actual and potential yield
based on statistical data at county level. The potential and water-limited yield of summer maize in the BTH region is 6854–8789
kg/hm2 and 6434–8741 kg/hm2, and the weighted average for whole region is 7861 kg/hm2 and 7185 kg/hm2, respectively. The simulated yields gradually decrease from northeast to southwest with changes in climatic conditions particularly
temperature and precipitation. Annual variation of potential yield is higher in the central and southern parts than the northeastern
part. Compared to potential yield, the water-limited yield has higher coefficient of variation (CV), because of precipitation
effects. The actual yield of summer maize was 2537–8730 kg/hm2, regionally averaged at 5582 kg/hm2, about 70% of the potential yield, implying that the region has room to increase the yield by improving crop management and
irrigation systems.
KeywordsWOFOST–summer maize–yield potential–yield gap–the Beijing-Tianjin-Hebei region
This paper confirmed AHP as the evaluation basic method, set up a universal evaluation index system of mineral-resource enterprises
ecological safety. This index system consisted of twenty indexes, it contained three aspect of environment pressure and quality
and resources environment protection ability, so the scientificity and integrity of index system were ensured. Based on the
characteristic, level and relevant standard of every evaluation index, evaluation criterion and the relevant grade were established.
An application example was giving showing the feasibility and effectiveness of the proposed approach. After empirical analysis,
pointed out that evaluating the ecological environment safety of mine-enterprise is not only necessary but also the base of
building ecological safety alarming mechanism. Meanwhile, it is the decision base of executing the sustainable development
strategy in mine-enterprise.
Adjusting cropping systems in order to increase their efficiency is a global issue. High yield and sustainability are the catchphrases of production in the 21st century, and agricultural production has to solve the balancing act between ecology and economy. Therefore, the requests for farmers, consultants and researchers are rising, and production modes are changing. Nevertheless, solutions have to be detected spatially explicit and locally adapted and accepted in order to be implemented successfully. Taking the North China Plain as an example, the productivity of arable land needs to be further increased by applying strategies to reduce or avoid negative environmental effects. Further yield increases are not possible by increasing input factors like N-fertilizer or irrigation water as N-fertilizer rates are extremely high and irrigation water is limited. However, yield increases might be possible by developing improved cropping strategies operated by cropping designs. Taking modeling and simulation tools into account back up the acceleration of research attainments and the understanding of cropping systems. The present thesis embraces the designing and modeling of such a potential cropping system, to wit strip intercropping. Thus, the main goals of the study were to analyze, design, evaluate, and in the end model intercropping. Intercropping systems are complex systems which strongly need to be designed and evaluated carefully in order to fulfill the premises of ecological and economical efficiency as well as sustainability. Multi-level interactions have to be weighted and taken into regard for evaluating datasets applicative for modeling and simulating intercropping. The main results of the study indicated, that traditional cropping systems like intercropping are widespread in China, where approximately one third of arable land is under intercropping. Reviewing cereal intercropping systems in China, the four agro-ecological regions Northeast and North, the Northwest, the Yellow-Huai River Valley and the Southwest could be classified, distinguished and described. Intercropping offers a great variation of species combination, benefits as well as challenges for cropping systems design and farmers. Carefully balanced between facilitation and competition, intercropping bears the potential of increased yield and yield stability, income security, resource use efficiency and biodiversity. Intercropping gives evidence about traditional cropping systems with the potential for future production systems under the paradigm of sustainability. Further, results from conducted field experiments indicated that border effects are the key component of intercropping performance. Nevertheless, analyzing strip intercropping statistically has peculiarities as they lack in randomization because the cropping system imposes alternating strips. Thus, spatial variability and its effect on yield were regarded differently within a geo-statistical analysis. In addition to the geo-statistical analysis, the crop growth modeling approach paid tribute to monocropping effects as well as to field border effects occurring in strip intercropping systems. Further on a model-based approach was tested to quantify multi-level interactions with special regard to changing microclimatic conditions and to optimize intercropping systems from an agronomical point of view. In comparison to other interspecific competition modeling approaches, a shading algorithm was evaluated and implemented into the process-oriented crop growth model DSSAT in order to simulate competition for solar radiation. More common in modeling mixed intercropping, a modified Beers law subroutine has been used instead, e.g. in APSIM. APSIM and DSSAT were compared by modeling the conducted field trials. As a result, the Beers law approach was not capable to model strip intercropping. In contrast, the modeling with a changed DSSAT model showed that applying a simple shading algorithm that estimated the proportion of shading in comparison to the monocropping situation and in dependency from neighboring plant height seems to be a promising approach. The results indicated that competition for solar radiation in those systems is a driving force for crop productivity but neither the most dominant nor the one and only. Resource distribution and allocation in space and time seems to be more important than the total amount of resources. Those effects have to be taken into account when simulating interspecific competition. Definiert als der Anbau von zwei oder mehr Feldfrüchten auf der gleichen Fläche und innerhalb der gleichen oder einer sich überlappenden Vegetationsperiode, bietet Intercropping eine große Bandbreite an Kombinationsmöglichkeiten von Feldfrüchten, verbunden mit vorteilhaften und nachhaltigen Effekten für die jeweiligen Kulturarten. Intercropping ist aber gleichzeitig eine Herausforderung für jeden Landwirt und stellt hohe Ansprüche an die Gestaltung des jeweiligen Produktions- oder Anbausystems. Intercropping ist in China weit verbreitet. Schätzungen zufolge wird Intercropping auf rund einem Drittel der gesamten Anbaufläche praktiziert. Intercropping gilt als ein Anbausystem, welches bei geringerem Betriebsmitteleinsatz höhere Erträge oder Gewinne erzielt, verglichen mit den ausgedehnten Monocropping Systemen moderner Agrar-Industriebetriebe. Damit belegt Intercropping, dass in traditionellen Anbausystemen ein Potential für zukünftige und nachhaltige Produktionssysteme schlummert. Um diesen Paradigmen und um politischen, sozialen und ökonomischen Prämissen gerecht zu werden, muss die Agrarforschung Lösungen und Strategien für angepasste Produktionssysteme bereitstellen und das in immer kürzeren Zeitspannen. Der Einsatz von computergestützten Pflanzenwachstumsmodellen, mit deren Hilfe komplexe Anbausysteme regional und überregional, sowie über längere Zeiträume hinweg simuliert und analysierte werden können, hat sich dabei als wertvoll erwiesen. Wie Intercropping Systeme gestaltet werden müssen und welche Probleme dabei auftauchen, welche Datengrundlage für eine Modellierung benötigt wird und welche systemimmanenten Interaktionen berücksichtig werden müssen, sind Gegenstand der vorliegenden Dissertation. Allerdings gestaltet sich die statistische Auswertung von speziell Strip Intercropping als schwierig, da Intercropping-Versuche aufgrund der zwangsläufig streifenförmigen Anordnung nicht randomisiert werden können. Intercropping bedarf also einer räumlichen Betrachtungsweise, um ertragsrelevante Effekte adäquat abzuschätzen und statistisch abzusichern. Deshalb wurden die Versuche geostatistisch ausgewertet und mehrere räumliche Modelle evaluiert und getestet, um die Modellgüte zu verbessern. Nicht nur die statistische Auswertung von Intercropping ist diffizil, auch die Datengrundlage von Intercropping in China ist lückenhaft. Im Vergleich zu anderen Ländern wie beispielsweise Indien oder Teilen Afrikas, wo Intercropping gängige Praxis ist, scheint die Dokumentation und Erforschung von Intercropping Systemen in China Nachholbedarf zu haben. In einer Literaturstudie wurde deshalb ein erster Versuch unternommen, China in agro-klimatische Regionen hinsichtlich ihres Potentials und ihrer Verbreitung von Getreide betonten Intercropping Systemen einzuteilen. In einer zweiten Literaturstudie wurde dargestellt, welche Modelle für Intercropping bereits evaluiert, kalibriert und validiert wurden. Exemplarisch für ein prozess-orientiertes Pflanzenwachstumsmodell, welches multiple Anbausysteme und deren Konkurrenz um Sonnenlicht mithilfe des Beer-Lambertschen Gesetzes simuliert, wurde APSIM gewählt. Dieser in der Forschung recht gängige Ansatz wurde mit dem in der vorliegenden Dissertation evaluierten, getesteten und in DSSAT implementierten Beschattungs-Algorithmus verglichen. Mit dem DSSAT Modell war es bislang nicht möglich, Intercropping zu simulieren. Es zeigte sich, dass es mit einem modifizierten Beer-Lambertschen Gesetz nicht möglich war, Strip Intercropping adäquat zu simulieren. Unter der Voraussetzung, dass es im Strip Intercropping einen Gewinner und einen Verlierer gibt, das heißt, dass eine Kulturart mehr Sonnenlicht erhält als im Monocropping und eine andere dafür weniger, ist der Beer-Lambertsche Ansatz viel versprechend und verwendbar. Die Kompensationsfähigkeit einer Fruchtart kann jedoch nicht simuliert werden, ebenso keine Ertragssteigerung der im System dominanten Fruchtart. Im Gegensatz dazu zeigte sich, dass der Beschattungs-Algorithmus, der in DSSAT integriert wurde, beide Systeme Intercropping und Monocropping simulieren konnte. Allerdings wurde in diesem Ansatz zusätzlich berücksichtig und getestet, dass Konkurrenz um solare Einstrahlung nicht die einzig bestimmende ist. Der Beschattungs-Algorithmus konnte zwar einen Teil des Ertragszuwachses im Intercropping erklären beziehungsweise simulieren, allerdings erst unter Berücksichtigung mikroklimatischer Effekte. Der Allokation von Pflanzenwachstumsfaktoren in Raum und Zeit kommt in Intercropping Systemen eine größere Rolle zu als deren absolute Höhe oder Menge. Solche Effekte müssen berücksichtig werden, um die Modellierung von Strip Intercropping weiterhin zu verbessern und Strip Intercropping Systeme zu optimieren.
Poor vegetation cover is generally considered to be a major factor causing soil erosion on the Loess Plateau in China. It has been argued that tree planting restoration is ineffective, and natural re-vegetation is an alternative ecological solution for restoring abandoned cropland and controlling soil erosion. The aims of this study were to investigate the characteristics of soil seed banks and to assess the natural restoration potential of abandoned cropland in the hilly-gullied Loess Plateau. The soil seed bank was identified by the germination method with the soil samples, which were collected at four sampling times (April, August, and October 2005 and August 2006) from 12 plots abandoned 3-30 years prior to sampling. The seed bank densities of all of the samples in the 0-10 cm soil layer varied from 1,067 ± 225 to 14,967 ± 1,606 seeds m(-2). Fifty-one species (24 annual and 27 perennial species) belonging to 18 families were identified, and 39% of these species belonged to the families Compositae and Gramineae. The pioneer species Artemisia scoparia dominated the seed bank, with an average seed density of 3,722 seeds m(-2), and accounted for 74.4% of the seeds in the bank. The local dominant species (such as Lespedeza davurica, Artemisia gmelinii, Bothriochloa ischaemun and Stipa bungeana) of the later succession stages also existed at densities varying from 17 to 1, 383 seeds m(-2). The combination of soil seed bank characteristics, reproductive traits of the species, the specific landscape conditions indicates that the potential to restoring the abandoned croplands in the hilly-gullied Loess Plateau via natural re-vegetation could be substantial.
A generic methodology is presented for exploration of sustainable land use options at the regional level by quantifying trade-offs between socioeconomic and biophysical sustainability objectives. The methodology is called SOLUS (Sustainable Options for Land USe), and was developed over a ten year period of investigation in the Northern Atlantic Zone of Costa Rica. SOLUS includes a linear programming model, technical coefficient generators for livestock and cropping activities and a geographic information system. The linear programming model maximizes regional economic surplus subject to a flexible number of resource and sustainability constraints. Economic sustainability indicators are economic surplus and labor employment, and biophysical ones include soil N, P and K balances, pesticide use and its environmental impact, nutrient losses and a proxy for trace gas emissions. The capabilities of the methodology are illustrated for the Northern Atlantic Zone of Costa Rica. Though ample scope exists for reducing environmental effects and introducing sustainable production systems separately, pursuing both objectives simultaneously, considerably reduces economic surplus and agricultural employment. Agricultural area can be decreased and forested area increased without severely affecting the regional economic surplus.
The management of sustainable, lower-input agroecosystems needs to be more sophisticated than high-input systems. This subject is introduced by describing: types and characteristics of multiple cropping, and its potential for US and European agriculture; minimum (conservation) tillage practices and associated problems; agroforestry and the types of possible agroforestry systems, mentioning the tree species commonly grown in alley cropping systems as microclimate modifiers, soil nutrient concentrators, windbreaks and firewood providers, as well as its potential for US and European agriculture; and integrating plant and animal systems. -J.W.Cooper
Scientific planning for soil and water conservation requires knowledge of the relations between those factors that cause loss of soil and water and those that help to reduce such losses. The soil loss prediction procedure presented in this handbook provides specific guidelines which are needed for selecting the control practices best suited to the particular needs of each site. The procedure is founded on an empirical soil loss equation that is believed to be applicable wherever numerical values of it factors are available. KEYWORDS: TROPAG textbar Miscellaneous subjects textbar Climatology textbar Land Conservation and Management textbar USA (Mainland).
In land use plans, fertilizer recommendations are indispensable to avoid soil nutrient depletion or soil water pollution. Nutrient relations of five cereals have been evaluated on the basis of a literature review with the aim of arriving at such fertilizer recommendations at regional level. Nutrients considered were nitrogen, phosphorus and potassium for millet, sorghum, maize, rice and wheat. The relevant nutrient relations are fertilizer nutrient application to nutrient uptake, and nutrient uptake to crop yield. In addition, post-anthesis nutrient uptake is considered. Subsequently, obtained results are used in simulation modelling exercises to calculate the time required to attain an equilibrium nutrient balance and to investigate the effect of erosion control and straw recycling. Although fertilizer requirements could be assessed for each of the five cereals, monitoring of nutrient supply from natural sources remains necessary. Moreover, research on fertilizer use should focus on improvement of fertilizer recoveries and multiperiod models for both N and P uptakes by crops to allow quantitative land use planning where the time scale is included.
This paper describes a formalized approach to identify and engineer future-oriented land use systems. Such land use systems can be used to explore options for strategic decision making with respect to land use policy and to do ex-ante assessment of land use alternatives to be further tested or developed in experimental settings. The so-called goal-oriented approach consists of three steps: (1) goal-oriented identification and design of land use systems; (2) quantification of biophysical production possibilities; and (3) defining the optimal mix of inputs, i.e. the production technique, required to realize production possibilities. The goal-oriented identification and design depends on the land-related objectives of a system under study, whereas plant, animal and environmental characteristics determine biophysical production possibilities. Characteristics of the production technique determine the realization of production possibilities. General guidelines are given to structure the specification and number of alternatives to be explored and to apply agro-ecological principles required for quantification of future-oriented land use systems. Concepts of the approach are illustrated with data from the northern Atlantic zone of Costa Rica and the Sudano–Sahelian zone of Mali. Finally, suggestions are given for the application of the approach at spatial and temporal scales exceeding the field level and time horizon of 1 year.
To support the different phases of a policy making process aimed at changing land use, distinct types of land use studies are required. This paper focuses on exploratory land use studies and their role in the phase of formulating strategic policy objectives. Exploratory land use studies contribute to a transparent discussion on policy objectives by showing ultimate technical possibilities and consequences of imposing different priorities to agro-technical, food security, socio-economic and environmental objectives. A methodology is presented in which science-driven technical information is confronted with value-driven objectives under given values of exogenous variables (e.g. regarding population growth and requirements for agricultural produce). Land use scenarios are generated showing consequences of different priorities for objectives by using natural resources and technical possibilities in different ways. Applications of such an approach are given for the global, regional and farm level, each addressing specific questions and target groups. The paper focuses on the type of results these studies produce and their role in the societal and political debate on strategic land use policy and planning. It is concluded that if exploratory land use studies are carried out in true interaction with target groups, they may well contribute to the debate and learning on sustainable land use options and a purposeful identification of effective policy instruments in a next phase of the policy making process.
A generic methodology is presented for exploration of sustainable land use options at the regional level by quantifying trade-offs between socio-economic and biophysical sustainability objectives. The methodology is called SOLUS (Sustainable Options for Land USe), and was developed over a ten year period of investigation in the Northern Atlantic Zone of Costa Rica. SOLUS includes a linear programming model, technical coefficient generators for livestock and cropping activities and a geographic information system. The linear programming model maximizes regional economic surplus subject to a flexible number of resource and sustainability constraints. Economic sustainability indicators are economic surplus and labor employment, and biophysical ones include soil N, P and K balances, pesticide use and its environmental impact, nutrient losses and a proxy for trace gas emissions. The capabilities of the methodology are illustrated for the Northern Atlantic Zone of Costa Rica. Though ample scope exists for reducing environmental effects and introducing sustainable production systems separately, pursuing both objectives simultaneously, considerably reduces economic surplus and agricultural employment. Agricultural area can be decreased and forested area increased without severely affecting the regional economic surplus.
Serious soil loss, food insecurity, population pressure, and low income of the rural population are interrelated, and consequently result in a spiral of unsustainability in the Loess Plateau, China. This thesis takes Ansai County in the Loess Plateau of China as a case study, to explore strategic land use options that may break the unsustainability spiral and meet goals of regional development. A systems analysis approach has been applied, in which fragmented and empirical information of the biophysical and agronomic conditions is integrated with well-adapted production ecological principles and other knowledge sources.With respect to the land use problems and regional development objectives, alternative production activities (systems) have been identified and quantified using a 'target-oriented approach' and the concept of 'best technical means', and based on information obtained from a quantitative land evaluation (based on the EPIC model), experimental data, literature and expert knowledge. Production activities have been quantified for cropping, fruit, grassland and firewood production systems, and animal husbandry. Production techniques emphasize soil conservation, productivity, use efficiency or low emission of chemicals. The quantified production activities, resource constraints, and socio-economic and environmental objectives have been incorporated into a multiple goal linear programming model that is used to optimize land use allocation, evaluate trade-offs among objectives and evaluate policy scenarios.The results reveal that the goals of food security and soil conservation in Ansai can be easily achieved from a biophysical and agro-technical point of view. Current slope cultivation and the resulting serious soil loss can be greatly reduced, while still guaranteeing food security for the rural population (in 2020). The soil loss control is, to a large extent, in line with the goals of increasing crop productivity and labor productivity (net agricultural return per laborer). In the long term, terracing and crop rotations with alfalfa could be the best options for soil conservation and also for agricultural production. The large rural labor force can be used for terrace construction. Alfalfa can fix nitrogen, and thus greatly reduce the demand for fertilizer N, and also improve soil fertility.The large rural population and the lack of off-farm employment opportunities could be the most important factor affecting rural development in Ansai. This is evident from the trade-off results, i.e., increasing the total employment in agriculture leads to an apparent adverse effect on many other objectives. However, there is a potential for maintaining high agricultural employment at a reasonable income level. The current low net return due to the very limited external inputs and poor crop and soil management can be substantially improved by efficient resource use and appropriate inputs.This research work contributes to the understanding of regional problems and agricultural development potentials. The results show agro-technical possibilities for breaking the spiral of unsustainability in this very fragile and poorly endowed region. Soil conservation, food security, employment and income for the rural population can be greatly enhanced by appropriate land use and agro-techniques. To promote actual development towards the identified options, appropriate policy measures aimed at improving the land tenure system and controlling population growth must be developed and implemented. The explored land use options enable a much more targeted policy development. In addition, the study can contribute to the formulation of a research agenda for research at field, crop and animal level.
A manual for prototyping Integrated and Ecological Arable Farming Systems (I/EAFS) in interaction with pilot farms is presented. It concerns a comprehensive and consistent approach of 5 steps. Step 1 is establishing a hierarchy of objectives considering the shortcomings of current farming systems in the region. Step 2 is transforming the objectives in a set of multi-objective parameters, to quantify them and establishing a set of multi-objective farming methods to achieve them. Step 3 is designing a theoretical prototype by linking parameters to farming methods and designing the methods in this context until they are ready for initial testing. Step 4 is laying out the prototype on at least 10 pilot farms in appropriate variants and testing and improving the prototype (variants) until the objectives, as quantified in the set of parameters, have been achieved (after repeated layout). Step 5 is disseminating the prototype (variants) to other farms with gradual shift in supervision from researchers to extensionists. This 5 steps method of prototyping has been elaborated and tested by a European network of more than 20 research teams, sponsored by the European Union (AIR-concerted action). The teams express their achievements in a consistent set of 6 parts of an identity card of their prototype. The 6 parts of the EAFS-prototype of the author's team are presented to illustrate the method of prototyping. Part 6 presents the state of the art. It shows that the results desired have progressively been achieved, which may be considered as the best proof of the effectiveness of prototyping.
Definitions and concepts of production ecology are presented as a basis for development of alternative production technologies characterized by their input-output combinations. With these concepts the relative importance of several growth factors and inputs is investigated to explain actual yield levels and resource-use efficiencies. Differences between potential and actual levels are analyzed to open ways for improved production technologies. The basis of the analysis is knowledge of basic physical, chemical, physiological and ecological processes at soil, field and crop level. New production technologies and their input-output combinations can be used in studies aimed at the exploration of options for sustainable agricultural production systems and land use. The concepts allow a systematic analysis and quantification of input-output combinations and clearly discriminate between bio-physical possibilities and socio-economic constraints and objectives. They help in defining objectives and means for agricultural production and land use, and may be valuable as aids to communication between various disciplines involved in studying the possibility and feasibility of future production technologies and land use options. The concepts production level, physical environment, target-oriented approach, production technique, production activity, and production orientation are applied to identify new technologies and production systems at various levels of scale, each requiring different types of information. In this paper some examples of applications are given at field, farm and at regional level.
In the industrialized countries dramatic decreases in the number of people employed in agriculture have been made possible by a rise in soil and labour productivity. There is scope for these to improve further, particularly in developing countries. Potential yields are determined by the characteristics of the crop, local temperature and sunlight. Because the availability of nutrients and that of water are limiting for at least part of the growing season in most agricultural lands, attainable yields are lower than potential yields. Proper management of nutrient inputs, such that optimum use is made of each, can reduce this gap without causing negative environmental side-effects. Actual yields are lower than attainable yields because of growth-reducing factors, such as pests, diseases and weeds. For sustainable agriculture these should be controlled mainly by biological measures. There are many possibilities for this, thus biocides may be used as a last resort not as preventive insurance. Potential yields of rice and sugarcane can reach 30,000 kg ha-1 per year of consumable organic matter, sufficient to feed 120 people. Such yields cannot be achieved on all agricultural land, but it is estimated that world food production could support a population of 80 thousand million, if they were all vegetarian and required only 1500 m2 for non-food-related purposes. The green revolutions that occurred in the Western industrialized countries in the late 1940s and early 1950s and in Asia in the late 1960s and early 1970s need to be followed by a similar increase in agricultural productivity in Africa and West Asia to feed their rapidly growing populations. Better use of fertilizers and good water management require well-educated farmers with the financial means to implement long-term strategies. If these developments are managed properly, food production for the ever-increasing human population can be guaranteed and the burden on the environment and natural habitats reduced, enabling the development of sustainable agricultural systems.
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