Figure
Source publication
Sugarcane is an important commercial crop for rural farmers in sub-Sahara Africa. To increase its productivity, farmers need to adopt better agronomic practices at all cane production stages. Proper and timely monitoring of pests and diseases must be done for early detection and control. This work therefore highlights key practices aimed at improvi...
Context in source publication
Similar publications
The present study was conducted during 2009-10 at Regional Sugarcane Research Station, Navsari Agricultural University, Navsari to estimate the genetic variability and interrelationship among cane yield and various cane yield components in forty diverse genotypes of sugarcane. Study revealed sufficient variability in the genotypes under study for a...
Citations
... In Uganda, although nearly all sugarcane farmers leave residues standing on the fields and employ tillage operations at seedbed preparation and weeding, fertilizer application practices among these farmers can greatly differ due to financial reasons (Otieno et al., 2019). The majority of the farmers typically apply a one-time standard fertilizer dose of urea ((NH 2 ) 2 CO; 70 kg N ha -1 ) mixed with muriate of potash (KCl; 23 kg K ha -1 ) to the sugarcane fields during the growth cycle. ...
Tropical deforestation for fertilizer-based agriculture has greatly increased in the last decades resulting in significant greenhouse gas (GHG; carbon dioxide (CO 2), methane (CH 4), and nitrous oxide (N 2 O)) emissions. Unfortunately , empirical studies on soil GHG fluxes from African deforestation hotspots are still limited, creating uncertainties in global GHG budgets. Therefore, we assessed how soil GHG fluxes along with their auxiliary controls (water filled pore space (WFPS), temperature, and mineral nitrogen (N)) differed between the forest and sugarcane plantations. This assessment was based on monthly (forest) and intensive (sugarcane) GHG and auxiliary measurements between May 2019 and June 2020. Measurements were conducted in four reference forest plots and 12 sugarcane plots randomly assigned to three fertilization treatment groups (low, standard, and high), representing the fertilization gradient used by sugarcane farmers in Uganda. Despite the use of different fertilization rates as treatments for the sugarcane experiment, neither auxiliary controls nor soil GHG fluxes significantly differed among the treatments. Soil CO 2 effluxes were higher under sugarcane (17.6 ± 0.0 Mg C ha-1 yr-1) compared to forest (14.5 ± 0.1 Mg C ha-1 yr-1 ; p < 0.001) because of the higher autotrophic respiration from the sugarcane's fine root biomass and the microbial decomposition of the sugarcane's larger soil organic carbon (SOC) stocks. Conversely, soil CH 4 uptake under sugarcane (− 1.1 ± 0.0 kg C ha-1 yr-1) was three times lower than under forest (− 3.1 ± 0.0 kg C ha-1 yr-1 ; p < 0.001), owing to the likely alteration of methanotroph abundance upon conversion. Likewise, soil N 2 O emissions were smaller under sugarcane (1.3 ± 0.0 kg N ha-1 yr-1) compared to forest (1.8 ± 0.0 kg N ha-1 yr-1 ; p < 0.001) because excess N from fertilizer addition in the sugarcane was either lost through leaching or taken up by the sugarcane crop. Only seasonal variability in WFPS, among the auxiliary controls, affected CH 4 uptake at both sites (p < 0.001) and soil CO 2 effluxes under sugarcane (p = 0.018). Noteworthy, soil N 2 O fluxes from both sites were unaltered by the seasonality-mediated changes in auxiliary controls. We conclude that even with the increased SOC sequestration and the lower N 2 O emissions under sugarcane compared to forest, the forest-sugarcane conversion resulted in a yearly net C loss of 2.8 Mg CO 2-eq ha-1 from soils to atmosphere, largely arising from the higher soil CO 2 effluxes and to a smaller extent from a reduced CH 4 uptake under sugarcane.
... Life cycle analysis of sugar production in Kenya shows many pathways through which nutrients and BC are added to the environment. First, fertilizers contribute to the average input of 147 kg/ha N and 79 kg/ha P, respectively (Otieno et al., 2019). Secondly, the need for lime in sugar processing has seen the development of industries such as the Homa Lime Mining Company and others. ...
Lake Victoria, a lifeline for millions of people in East Africa, is affected by anthropogenic activities resulting in eutrophication and impacting the aquatic life and water quality. Therefore, understanding the ongoing changes in the catchment is critical for its restoration. In this context, catchment and lake sediments are important archives in tracing nutrient inputs and their dominant sources to establish causality with human activities and productivity shifts. In this study, we determine the 1) changes in concentrations of total organic carbon (TOC), black carbon (BC), total nitrogen (TN), C/N ratio, and phosphorous (P) fractions in catchment sediments and the open lake, 2) distribution of diatom population in the lake, and 3) land use and land cover changes in the catchment. The distribution of TOC, BC, TN, C/N, and P correlate while showing spatial and temporal variations. In particular, the steady increase in BC confirms atmospheric inputs from anthropogenic activities in the catchment. However, lake sediments show more variations than catchment-derived sediments in geochemical trends. Notably, the catchment has undergone dramatic land use changes since the 1960s (post-independence). This change is most evident in satellite records from 1985 to 2014, which indicate accelerated human activities. For example, urban growth (666-1022%) and agricultural expansion (23-48%) increased sharply at the expense of a decline in forest cover, grassland, and woodlands in the catchment. Cities like Kisumu and Homa Bay expanded, coinciding with rapid population growth and urbanization. Consequently, nutrient inputs have increased since the 1960s, and this change corresponds with the divergence of diatom communities in the lake. In addition, the transition to Nitzschia and cyanobacteria mark increasing cultural eutrophication in the lake. The geochemical trends and statistical data support our inference(s) and provide insights into urban development and agriculture practices, which propelled increased nutrients from the catchment and productivity shifts in the lake.
... Life cycle analysis of sugar production in Kenya shows many pathways through which nutrients and BC are added to the environment. First, fertilizers contribute to the average input of 147 kg/ha N and 79 kg/ha P, respectively (Otieno et al., 2019). Secondly, the need for lime in sugar processing has seen the development of industries such as the Homa Lime Mining Company and others. ...
Tropical deforestation for fertilizer-based agriculture has greatly increased in the last decades resulting in significant anthropogenic greenhouse gas (GHG) emissions. Unfortunately, empirical studies on soil GHG fluxes (carbon dioxide (C2), methane (CH4), and nitrous oxide (N2O)) from African tropical deforestation hotspots are still limited, creating uncertainties in global GHG budgets. Therefore, we quantified soil GHG fluxes and their potential auxiliary controls (water-filled pore space (WFPS), temperature and mineral nitrogen) from four forest plots and 12 replicate plots of a completely randomized design (CRD) experiment premised in a neighboring 20-year-old sugarcane plantation in northwestern Uganda. Despite the use of different fertilization rates (low, standard, and high) as treatments for the sugarcane CRD experiment, neither auxiliary controls nor soil GHG fluxes significantly differed among the CRD treatments. Soil CO2 effluxes were higher in the sugarcane (17.6 ± 0.0 Mg C ha-1 yr-1) than in the forest (14.5 ± 0.1 Mg C ha-1 yr-1; p < 0.001) because of the increased autotrophic respiration from the sugarcane’s fine root biomass and the likely exposure of its larger SOC stocks to microbial decomposition through ploughing operations. Conversely, soil CH4 uptake was three times lower in the sugarcane (-1.1 ± 0.0 kg C ha-1 yr-1) than in the forest (-3.1 ± 0.0 kg C ha-1 yr-1; p < 0.001), which we suspect was due alteration of the methanotroph abundance upon the conversion. Likewise, soil N2O emissions were smaller in the sugarcane (1.3 ± 0.0 kg N ha-1 yr-1) than the forest (1.8 ± 0.0 kg N ha-1 yr-1; p < 0.001) which is likely because excess N from fertilizer addition in the sugarcane was either lost through leaching or taken up by the sugarcane crop. Only seasonal variability in WFPS, among the auxiliary controls, affected CH4 uptake at both sites and soil CO2 effluxes in the sugarcane (p = 0.018). Noteworthy, soil N2O fluxes from both sites were unaltered by the seasonality-mediated changes in auxiliary controls. Overall, our results suggest that forest conversion for sugarcane cultivation alters soil GHG fluxes by increasing soil CO2 emissions and reducing both soil CH4 sink strength and soil N2O emissions.
