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Mean RLD (root length density; filled circles, full line) to 100 cm depth for winter oilseed rape in 40 experiments across the UK from 2004 to 2013, compared with published reference values from Barraclough (1989; open circles, dashed line). The cRLD of 1 cm cm –3 for wheat is
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Root length density (RLD) was measured to 1 m depth for 17 commercial crops of winter wheat (Triticum aestivum) and 40 crops of winter oilseed rape [Brassica napus; oilseed rape (OSR)] grown in the UK between 2004 and 2013. Taking the critical RLD (cRLD) for water capture as 1cm cm(-3), RLDs appeared inadequate for full water capture on average bel...
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... 2 and 4) demonstrate a very wide range, from 2.8 km m -2 to 26.7 km m -2 . The mean total root length for the 40 crops was 26.7 km m -2 . The low- est estimated percentage of roots in the top 0.5 m was 61% and the greatest was 96%. The RLDs in each of all horizons (including extrapolated vales for some horizons at 21 sites) are summarized in Fig. 2. There were more roots in the top- soil for OSR than for winter wheat, with average RLDs of 2.66 cm cm -3 and 1.69 cm cm -3 in the 0-20 and 20-40 soil horizons. RLD decreased down the soil profile, with aver- age RLDs of 0.68, 0.63, and 0.55 cm cm -3 in the lowest three horizons. As for wheat, the rate of decrease in the amount of ...
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... soil horizons. RLD decreased down the soil profile, with aver- age RLDs of 0.68, 0.63, and 0.55 cm cm -3 in the lowest three horizons. As for wheat, the rate of decrease in the amount of roots in the lower horizons was less than that between the two upper horizons. The maximum RLD in the topsoil of 7.43 cm cm -3 was much greater than the average (Fig. 2), and maxima in the 40-60 and 60-80 cm soil horizons were very similar at 1.95 cm cm -3 and 1.89 cm cm -3 , respectively. The minimum RLD in the topsoil was 0.55 cm cm -3 , with 0.07 cm cm -3 in the 80-100 cm soil horizon, so was less than the minimum RLD for wheat. Barraclough et al. (1989) reported an RLD of 7.97 cm cm -3 for OSR in ...
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... are limited data available on rooting in OSR, and no published cRLD for OSR. If the same cRLD of 1 cm cm -3 as for wheat is assumed, Fig. 2 indicates that average root intensity for winter OSR became inadequate below ~0.4 m soil depth. There was sufficient rooting in the top two soil horizons; however, in the lower horizons the average RLD was around half of the critical value. The minimum measured RLDs were adequately rooted in the 0-0.2 m soil horizon, but this was not ...
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... wheat and OSR crops are grown on the same land, it might be expected that RLDs for wheat and OSR would be similarly small. However, the topsoil RLDs for OSR (Fig. 2) were larger than those for wheat (Fig. 1), the largest of these being consistent with the reference values. Whether this difference is due to different topsoil cultivations for the two species or to inherent interspecific differences is unclear. However, the OSR RLDs for the lower soil horizons were similarly small as those for wheat ...
Citations
... A narrower nodal root angle at elongation correlating with yield only after an OSR precrop suggests that the root systems benefit from going deeper after this precrop, but not wheat. OSR crops tend to have shallower rooting systems, thus depleting more resources on the surface 58 . A deeper rooting system at an early stage may allow for access to untapped nutrients after an OSR precrop, but this would not be the case after a wheat precrop as the roots would go to similar levels and thus areas within reach at this stage would be equally depleted. ...
Roots play a pivotal role in the adaption of a plant to its environment, with different root traits adapting the plant to different stresses. The environment affects the Root System Architecture (RSA), but the genetic factors determine to what extent, and whether stress brought about by extreme environmental conditions is detrimental to a specific crop. This study aimed to identify differences in winter wheat RSA caused by cultivation region and practice, in the form of preceding crop (precrop), and to identify if modern cultivars used in Sweden differ in their reaction to these environments. This was undertaken using high-throughput phenotyping to assess the RSA. Clear differences in the RSA were observed between the Swedish cultivation regions, precrop treatments, and interaction of these conditions with each other and the genetics. Julius showed a large difference between cultivars, with 9.3–17.1% fewer and 12–20% narrower seminal roots. Standardized yield decreased when grown after wheat, 23% less compared to oilseed rape (OSR), and when grown in the Southern region, 14% less than the Central region. Additionally, correlations were shown between the root number, angle, and grain yield, with different root types being correlated depending on the precrop. Cultivars on the Swedish market show differences that can be adapted to the region-precrop combinations. The differences in precrop effect on RSA between regions show global implications and a need for further assessment. Correlations between RSA and yield, based on root-type × precrop, indicate different needs of the RSA depending on the management practices and show the potential for improving crop yield through targeting genotypic and environmental conditions in a holistic manner. Understanding this RSA variance, and the mechanisms of conditional response, will allow targeted cultivar breeding for specific environments, increasing plant health and food security.
... It was maintained at levels above 84% and 79% in the two treatments subjected to water deficit. Maintaining optimal hydration of plants under water deficit is ensured mainly by water absorption efficiency [35,36]. Thus, the morpho-anatomical remodeling of roots occurring under water deficit plays a major role in this strategy [37,38]. ...
The productivity of durum wheat in Mediterranean regions is greatly reduced by water deficits that vary in intensity and time of occurrence. The development of more tolerant cultivars is the main solution for fighting these stresses, but this requires prior study of their mechanisms. The involvement of the root system in drought avoidance is of major importance. It is in this context that the present work attempts to establish the impact of morpho-anatomical remodeling of seminal roots on dehydration avoidance at the javelina stage in five durum wheat genotypes grown under three water regimes, 100%, 60% and 30% of field capacity (FC). In the last two treatments, which were applied by stopping irrigation, moisture was concentrated mainly in the depths of the substrate cylinders and was accompanied by greater root elongation compared with the control. The elongation reached rates of 20 and 22% in the ACSAD 1231 genotype and 12 and 13% in the Waha genotype, in the 60% FC and 30% FC treatments respectively. The seminal roots anatomy was also modified by water deficit in all genotypes but to different degrees. The diameter of vessels in the late metaxylem vessels was reduced, reaching 17.3 and 48.2% in the Waha genotype in the 60% FC and 30% FC treatments, respectively. The water deficit also increased the number of vessels in the early metaxylem, while reducing the diameter of its conducting vessels. ACSAD 1361 and Langlois genotypes stood out with the highest rates of diameter reduction. The morpho-anatomical transformations of the roots contributed effectively to the plants’ absorption of water and, consequently, to the maintenance of a fairly high relative water content, approaching 80%.
... Based on the response of crop plants to low P deficiency, it was found that in the group of plants with fibrous root systems, such as cereals, the morphological type of adaptation dominates. In contrast, legumes show a dominant physiological type of adaptation, involving the secretion of protons and organic acids into the rhizosphere [66]. In the case of cruciferous plants, three interacting types of adaptation should probably be considered. ...
Phosphorus resources, both in phosphate rocks and in the soil, are limited. However, effective food production is not possible without the use of P fertilizers. Recognizing and eliminating or at least ameliorating factors (hot spots) that interfere with the uptake and use of phosphorus (P) by crop plants is of key importance for effective use of both P and nitrogen (N) on the farm. Plants have developed many adaptation mechanisms to their environment, i.e., soil low in available phosphorus. The most important ones include the secretion of organic compounds into the rhizosphere and the association of plant roots with microorganisms. A classic example is mycorrhiza. These mechanisms can be used by the farmer to sequentially select plants in the crop rotation. The uptake of inorganic P (Pi) by plants from the soil is reduced by environmental (temperature and water) and soil factors (low content of available phosphorus, soil acidity, soil compaction). These factors are responsible for the growth and size of the root system. Mitigating these negative effects improves the efficiency of phosphorus uptake from the soil. The second group of critical factors, limiting both root growth and availability of phosphorus, can be effectively controlled using simple measures (for example, lime). Knowing this, the farmer must first control the level of soil fertility in the plant’s effective rooting zone and not only in the topsoil. Secondly, the farmer must multiply the productivity of applied mineral fertilizers used through targeted recycling: crop rotation, crop residues, and manure.
... Cumulative root length distribution was similar between the genotype groups, indicated by the comparable regression coefficients (Fig. 6). A large part of the roots was found in the topsoil, which is comparable to values reported by White et al. (2015). They found between 61 % and 96 % of wheat roots in the upper 50 cm at different locations, whereas 81-85 % of the root length was found in the upper 50 cm in our study. ...
... The growth of root system in the soil layer is crucial for soil water absorption (Guan et al., 2015;Feng et al., 2023). The larger RLD in the soil layers, the more soil water was absorbed by roots to satisfy the needs of plant growth at the late growth stage, which is conducive to achieving the higher grain yield (White et al., 2015). In the present study, the larger and deeper RLD was obtained with ISM, which implied that the ability to capture the deeper soil water and utilization efficiency of stored soil water under ISM was the highest. ...
The increasing costs of agricultural production and environmental concerns reinforce the need to reduce resource inputs. Improvements in nitrogen (N) use efficiency (NUE) and water productivity (WP) are critical for sustainable agriculture. We aimed to optimize management strategy to increase wheat grain yield, promote N balance, and improve NUE and WP. A 3-year experiment was conducted with four integrated treatments: conventional practice treatment (CP); improvement of conventional practice treatment (ICP); high-yield management treatment (HY), which aimed for maximizing grain yield regardless of resource inputs cost; and integrated soil and crop system management treatment (ISM), which aimed for testing an optimal combination of sowing date, seeding rate, and fertilization and irrigation management. The average grain yield for ISM was 95.86% of that for HY and was 5.99% and 21.72% higher than that for ICP and CP, respectively. ISM promoted N balance as relatively higher aboveground N uptake, lower inorganic N residue, and lowest inorganic N loss. The average NUE for ISM was 4.15% lower than that for ICP and was remarkably higher than that for HY and CP by 26.36% and 52.37%, respectively. The increased soil water consumption under ISM was mainly due to its increased root length density. Along with a high level of grain yield, ISM obtained a relatively adequate water supply due to the effective use of soil water storage, thereby increasing the average WP by 3.63%–38.10% in comparison with other integrated management treatments. These results demonstrated that optimized management strategy (appropriately delaying sowing date, increasing seeding rate, and optimizing fertilization and irrigation management) used under ISM could promote N balance and improve WP while increasing grain yield and NUE in winter wheat. Therefore, ISM can be considered a recommendable management strategy in the target region.
... Barraclough (1989) reported that the average root length density (RLD) of oilseed rape in the top 20 cm of soil is 8 cm cm -3 , and only 0.35 cm cm -3 at 60-180 cm of soil. In another study, the root length of oilseed rape in the top 40 cm of soil accounted for 70% of the total root length in the total 100 cm of soil (White et al., 2015). The 0-30 cm soil layer root of oilseed rape was sampled in the studies of Gu et al., (2016Gu et al., ( , 2019 and Arifuzzaman et al. (2019). ...
Oilseed rape (Brassica napus L.) is the most important temperate oil crop globally. Maintenance of soil phosphate (Pi) availability, through the application of Pi fertilizers and manures, is needed to maintain seed yield of oilseed rape. Over-application of the Pi fertilizers results in Pi accumulation in agricultural soils and adjacent ecosystems , where it can drive eutrophication in freshwater and coastal systems. In this study, two years of field experiments were conducted to explore the optimal Pi fertilizer application rate for four oilseed rape cultivars and the potential of nature-based solutions including Pi solubilizing bacteria (PSB) and rooting agent (RA) to reduce Pi fertilizer application rates for oilseed rape. The seed yields of cultivars Shengguang 168 (SG168) and Huayouza 9 (HYZ9) were significantly higher than those of cultivars Zhongyouza 19 (ZYZ19) and Zhongshuang 11 (ZS11) across all Pi application rates. In comparison with Farmers' fertilizer practice (P 26.2 , 26.2 kg P ha-1), Pi fertilizers could be reduced by more than 25% for the four cultivars, and be reduced by as much as 50% for SG168. The shoot dry weight and seed yield of ZS11 with the addition of RA at P 21.0 (21.0 kg P ha-1) in Expt. 2-1 and P 15.7 (15.7 kg P ha-1) in Expt. 2-2 showed no significant difference to that of P 26.2 at the ripening stage, but were significantly higher than that of P 21.0 and that of P 15.7 , respectively. At P 0 (0 kg P ha-1), addition of PSB significantly increased the shoot dry weight and seed yield of ZS11 at the ripening stage. However, at P 21.0 in Expt. 2-1 or at P 15.7 in Expt. 2-2, addition of PSB had no effect on shoot dry weight and seed yield of ZS11. These results highlighted the feasibility and potential to reduce the application rate and improve the use efficiency of Pi fertilizers in oilseed rape using nature-based solutions.
... Our results indicated that wheat roots were mainly concentrated in the 0-20 cm soil layer (Fig. 5 & 6), which is in line with Wang et al., 2014. Previous studies have shown that N applications promote wheat root growth, while excessive N application restrains root growth (White et al., 2015;Chen et al., 2020). Similarly, our results showed that both the RWD and RLD were much lower in the N240 treatment compared to that under the N180 and N120 treatments (Fig. 5 & 6). ...
The optimization of nitrogen (N) fertilization has become an ever more important global challenge with the aim of achieving high crop yields and high N use efficiency (NUE) with low environmental risks. The North China Plain (NCP) is China’s most important wheat (Triticum aestivum Linn.) production region, and a global hotspot for N fertilizer use. How much nitrogen can be saved compared to the farmers’ level that would not influence wheat yield, and lead to high NUE with low N surplus? It is still challenging as there are not enough evidences from the long-term experiments. Thus, continuous detailed observations from an ongoing long-term experiment in the NCP since 2010 with five N rates, namely 0 (N0), 60 (N60), 120 (N120), 180 (N180) and 240 (N240) kg N ha-1, were included in the study. Our results indicated that stable high wheat yield cannot be achieved without enough N inputs from the long-term, because of severely depleted N pool in the N0 and N60 treatments seriously influenced root growth and wheat development thus damaged wheat yield. Though highest wheat yield was obtained in the N240 treatment, the high N rate caused lowest NUE and largest N surplus with high soil mineral N (SMN) with the mean value of 143 kg N ha-1 at the 0-60 cm layer at harvest. Besides, both root weight density (RWD) and root length density (RLD) were much lower in the N240 treatment compared to that in the N180 treatment. Our integrative analyses clearly indicate that the optimal N application for achieving high yield, high NUE and low environmental risks in wheat production was 180 kg N ha-1 based on long-term observations. Our results should be beneficial for promoting sustainable wheat production in the NCP and similar regions with wheat-based double cropping over the world.
... Improvement of the harvest index (HI) is the greatest effect of the Green revolution, as it finally led to higher grain yields of cereals, including rice [54]. However, the exposition of dwarf genes has also caused a reduction in the root system size of wheat varieties, which is significantly smaller than that of the classic ones [55,56]. As a consequence, the semi-dwarf or dwarf growth mode of modern cereals varieties result in the higher yield, provided that the supply of nutrients (especially Nf) is high, and that the plants are strongly protected against pathogens [54,57]. ...
The Soil Fertility Clock (SFC) concept is based on the assumption that the critical content (range) of essential nutrients in the soil is adapted to the requirements of the most sensitive plant in the cropping sequence (CS). This provides a key way to effectively control the productivity of fertilizer nitrogen (Nf). The production goals of a farm are set for the maximum crop yield, which is defined by the environmental conditions of the production process. This target can be achieved, provided that the efficiency of Nf approaches 1.0. Nitrogen (in fact, nitrate) is the determining yield-forming factor, but only when it is balanced with the supply of other nutrients (nitrogen-supporting nutrients; N-SNs). The condition for achieving this level of Nf efficiency is the effectiveness of other production factors, including N-SNs, which should be set at ≤1.0. A key source of N-SNs for a plant is the soil zone occupied by the roots. N-SNs should be applied in order to restore their content in the topsoil to the level required by the most sensitive crop in a given CS. Other plants in the CS provide the timeframe for active controlling the distance of the N-SNs from their critical range.
... An apparent paradox for both traits of RSA is that the greatest RLD values in the topsoil, regardless of the crop, decline exponentially with depth [67]. Current studies on winter wheat and winter oilseed rape have shown that the critical RLD of 1 cm cm −3 was 32 and 45 cm, respectively [80]. These data indicate that there is no competition between roots for NO 3 -N below this depth. ...
Fertilizer Use Efficiency (FUE) is a measure of the potential of an applied fertilizer to increase its impact on the uptake and utilization of nitrogen (N) present in the soil/plant system. The productivity of N depends on the supply of those nutrients in a well-defined stage of yield formation that are decisive for its uptake and utilization. Traditionally, plant nutritional status is evaluated by using chemical methods. However, nowadays, to correct fertilizer doses, the absorption and reflection of solar radiation is used. Fertilization efficiency can be increased not only by adjusting the fertilizer dose to the plant’s requirements, but also by removing all of the soil factors that constrain nutrient uptake and their transport from soil to root surface. Among them, soil compaction and pH are relatively easy to correct. The goal of new the formulas of N fertilizers is to increase the availability of N by synchronization of its release with the plant demand. The aim of non-nitrogenous fertilizers is to increase the availability of nutrients that control the effectiveness of N present in the soil/plant system. A wide range of actions is required to reduce the amount of N which can pollute ecosystems adjacent to fields.
... The lower root length density (RLD) in the deep soil layers was the limiting factor for the full use of ASW (Zhang et al., 2004(Zhang et al., , 2009White, 2015;Zhang et al., 2020). The RLD among the different treatments in the 2019-2020 and 2020-2021 seasons is shown in Fig. 5. ...
... Root length density is the most appropriate parameter to describe plant root water absorption as compared with other root characteristics (Carvalho and Foulkes, 2013). The effective rooting depth of winter wheat has attracted much attention (White et al., 2015). If the surface roots can obtain sufficient water, root initiation will decrease exponentially with increasing soil depth (Gerwitz and Page, 1974;Aziz et al., 2017;Palta and Turner, 2019). ...
It is well-recognized that deep roots play a vital role in increasing soil water availability to crop water use, their ability in regulating the allocation of the crop water use during the growing season would also influence crop yield and water productivity. Experiments were conducted using tubes of 0.5, 1.0, 1.5 and 2.0 m in depth (with an inner diameter of 30.5 cm) and irrigation amounts varying from 90 to 500 mm for two seasons of winter wheat (2019–2020 and 2020–2021). The combinations of the different tube depth and irrigation created different situations in terms of maximum rooting depth and soil water availability to assess the functions of deep roots on regulation of soil water availability to crops, and if the deep root growth being economic or not in relating to crop production and water productivity (WP). The results showed that under the same seasonal evapotranspiration (ET), the shallower the root depth was, the lower the yield. Higher WP was achieved with deep root systems. Further analysis showed that higher proportion ET occurred during the reproductive stage for the treatments with deep roots, which increased the leaf photosynthetic rate and the duration of the greenness, resulting in higher harvest index and WP. Deep roots not only increased the soil water availability for crop water use, but also regulated the timing of the soil water use to favor an increased proportion of water use during the reproductive stage. The root: shoot ratio was slightly increased from the 0.5 m tube to 1.0 m tube, but under a sufficient water supply, root: shoot ratio gradually decreased in the 1.5 m and 2.0 m tubes, resulting in less root length corresponding to the unit grain production. The treatments with deep root systems increased the root efficiency. The results indicated that both the total available water and the allocation of the water consumption during the crop growing season influenced the yield and water productivity. Increasing rooting depth was an efficient regulation measure to optimize the allocation of water consumption and increase soil water availability to crops without increasing metabolic input in root growth.
