International Crops Research Institute for the Semi-Arid Tropics
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Fertiliser use efficiency, production risks and profitability of maize on smallholder farms in East Africa
Get PDFThe use of fertilisers in maize production has been the focus for many years of agronomic studies on research stations in East Africa. However, information on production risks and profitability of fertiliser use on smallholder farms is generally lacking because most of the early studies have focused on mean yields and yield components on research stations. This study applied rigorous analyses to determine conditions under which (1) production risks are low; (2) the recommended nitrogen (N) and phosphorus (P) fertiliser rates achieve a yield target of ≥3 t ha−1 believed to be a necessary condition to kick start a smallholder-led ‘green revolution’ in Africa and (3) N and P fertiliser use is profitable on smallholder farms in East Africa. Analysis of data from 464 on-farm trials in Kenya, Rwanda, Tanzania and Uganda revealed significant variations in production risks and nutrient use efficiency with season and soil type. On most sites, except in Uganda, production risks were lower with the recommended N and P fertilisers than the control during both the short and long rains. Production risks were three to four times higher with N and P fertiliser relative to the control on Lixisols and Ferralsols, but such risks were much lower on Nitisols, Leptosols, Vertisols, Plinthosols and Cambisols. The probability of exceeding grain yields of 3 t ha−1 with the recommended N and P rates was over 0.60 on Nitisols and Leptosols, but less than 0.20 on Lixisols and Plinthosols. The agronomic use efficiencies of N (AEN), P (AEP) and value cost ratios (VCR) were highest on Cambisols and lowest on Plinthosols. The VCR increased linearly with increase in AEN (R2 = 0.92) and AEP (R2 = 0.87) and less so with increase in grain yields (R2 = 0.47–0.60). Net present values indicated profitably of N and P fertiliser over the long term in only 30% of the site by season combinations in Uganda compared with 69% in Kenya, 81% in Rwanda and 84% in Tanzania. Patterns of N use efficiencies were different from P use efficiencies across soil types. Therefore, we recommend that N and P fertilisers should be appropriately targeted to soils where applied nutrients are used efficiently by maize crops
Sexual Compatibility Types in F1 Progenies of Sclerospora graminicola, the Causal Agent of Pearl Millet Downy Mildew
Get PDFSclerospora graminicola is primarily heterothallic in nature with two distinct mating types (G1 and G2); however, homothallism does exist in the pathogen populations. In this study, a cross was made between two self-sterile isolates (Sg 019, Mat-2, G2 × Sg 445-1, Mat-1, G1) of S. graminicola and a total of 39 F1 progenies were established. The study on sexual compatibility types in F1 progenies was conducted by crossing each F1 progeny with both the parents (Sg 445-1, Mat-1, G1; and Sg 019, Mat-2, G2). The results revealed the presence of four sexual compatibility types, viz. G1, G2, G1G2 and G0 (neuter) in the progenies. The G1G2 progenies that produced oospores with both the parents were found as self-fertile (homothallic) and self-sterile (heterothallic) types. Similarly, self-fertile parental type G1 and G2 progenies were designated as secondary homothallic, whereas self-sterile parental type G1 and G2 progenies were of heterothallic type. The result of the present study revealed Mendelian segregation of mating type locus in S. graminicola which indicates that sexual reproduction plays an important role in the evolution of new genetic recombinants in the pathogen. The study also helps in understanding the genetic structure of S. graminicola populations and potential for possible evolution of new virulences in the pathogen
Building sorghum seed sector along the grain market in Tanzania: Areas for policy support
Get PDFIn Tanzania, sorghum is the 3rd most grown cereal with approximately 500,000 tons produced per year (FAOSTAT, 2018). It is grown in semi-arid regions of Dodoma, Singida, Mara, Shinyanga, Mwanza, and Tabora regions. Farmers primarily produce sorghum for consumption (83%) rather than commercial purpose (17%). It is mainly used as human food, animal feeds, alcoholic beverages, and biofuels. In the past years, there has been an increase
in sorghum production from 676,772 tons in 2015 to 750,000 tons in 2020 (FAOSTAT, 2022). Recently, there is an increase in demand for sorghum since many people are increasingly getting aware of the health benefits that come with the consumption of sorghum like prevention of cancer, reducing tumor incidence, and lowering blood pressure (Saleh et al, 2013); and increase in sorghum demand among breweries like Serengeti Breweries Limited (SBL) (American sorghum, 2016). White sorghum is highly preferred in and outside the country because of its use, color and low tannin; and red sorghum is highly demanded in Lake Zone and Northern Highland of Tanzania and exported to Burundi and Rwanda. Tanzania mostly exports sorghum to Uganda, Rwanda, Kenya, Burundi, and United Arab Emirates (UAE). Sorghum grain in Tanzania hardly competes in both local and international markets because of the low-quality grain....
Changes in Ammonia-Oxidizing Archaea and Bacterial Communities and Soil Nitrogen Dynamics in Response to Long-Term Nitrogen Fertilization
Get PDFAmmonia oxidizing archaea (AOA) and bacteria (AOB) mediate a crucial step in nitrogen
(N) metabolism. The effect of N fertilizer rates on AOA and AOB communities is less studied in the
wheat-fallow system from semi-arid areas. Based on a 17-year wheat field experiment, we explored
the effect of five N fertilizer rates (0, 52.5, 105, 157.5, and 210 kg h
Quantifying Farm Household Resilience and the Implications of Livelihood Heterogeneity in the Semi-Arid Tropics of India
Get PDFThe vast majority of farmers in the drylands are resource-poor smallholders, whose livelihoods
depend heavily on their farming systems. Therefore, increasing the resilience of these smallholders
is vital for their prosperity. This study quantified household resilience and identified livelihoods
and their influence on resilience in the semiarid tropics of India by analysing 684 households.
A resilience capacity index was devised based on the composition of household food and non-food
expenditure, cash savings, and food and feed reserves. The index ranged from 8.4 reflecting highly
resilient households with access to irrigation characteristics, to -3.7 for households with highly limited
resilience and low household assets. The livelihoods were identified through multivariate analysis
on selected socioeconomic and biophysical variables; households were heterogeneous in their
livelihoods. Irrigated livestock and rainfed marginal types had the highest and lowest resilience
capacity index with the mean score of 0.69 and −1.07, respectively. Finally, we quantified the influence
of livelihood strategies on household resilience. Household resilience was strengthened by the
possession of livestock, crop diversification and access to irrigation. Low resilience is predominantly
caused by low household assets. The resilience capacity index and derived livelihood strategies
helps to understand the complexity of household resilience, and will aid in targeting technology
interventions for development
Detecting Soil pH from Open-Source Remote Sensing Data: A Case Study of Angul and Balangir Districts, Odisha State
Get PDFSoil sampling, collection, and analysis are a costly and labor-intensive activity that cannot cover the entire farmlands;
hence, it was conceived to use high-speed open-source platforms like Google Earth Engine in this research to estimate soil
characteristics remotely using high-resolution open-source satellite data. The objective of this research was to estimate soil
pH from Sentinel-1, Sentinel-2, and Landsat-8 satellite-derived indices; data from Sentinel-1, Sentinel-2, and Landsat-8
satellite missions were used to generate indices and as proxies in a statistical model to estimate soil pH. Step-wise multiple
regression (SWMR), artificial neural networks (ANN), and random forest (RF) regression were used to develop predictive
models for soil pH, SWMR, ANN, and RF regression models. The SWMR greedy method of variable selection was used to
select the appropriate independent variables that were highly correlated with soil pH. Variables that were retained in the
SWMR are B2, B11, Brightness index, Salinity index 2, Salinity index 5 of Sentinel-2 data; VH/VV index of Sentinel 1 and
TIR1 (thermal infrared band1) Landsat-8 with p-value\0.05. Among the four statistical models developed, the class-wise
RF model performed better than other models with a cumulative correlation coefficient of 0.87 and RMSE of 0.35. The
better performance of class-wise RF models can be attributed to different spectral characteristics of different soil pH
groups. More than 70% of the soils in Angul and Balangir districts are acidic soils, and therefore, the training of the dataset
was affected by that leading to misclassification of neutral and alkaline soils hindering the performance of single class
models. Our results showed that the spectral bands and indices can be used as proxies to soil pH with individual classes of
acidic, neutral, and alkaline soils. This study has shown the potential in using big data analytics to predict soil pH leading to
the accurate mapping of soils and help in decision support
Genetic approaches for assessment of phosphorus use efficiency in groundnut (Arachis hypogaea L.)
Get PDFProduction of phosphorus efficient genotypes can reduce environmental pollution. Identification of P-efficient groundnut genotypes is a need of the hour to sustain in P-deficient soils. The pot experiment showed significant differences between genotypes (G) and treatments (T) for all the traits and G × T interaction for majority of traits. The G × T × Y interaction effects were also significant for all
the traits except leaf P% (LP%), leaf acid phosphatase (LAP) and root dry weight (RDW). In lysimeter experiment, the effect of G, T and G × T were significant for leaf dry weight (LDW), stem dry weight (SDW), total transpiration (TT) and transpiration efficiency (TE). For traits, LDW, SDW, TT, TE, ICGV 00351 and ICGS 76; for SDW, TT, ICGV 02266 are best performers under both P-sufficient and deficient
conditions. Based on P-efficiency indices and surrogate traits of P-uptake, ICGV’s 02266, 05155, 00308, 06040 and 06146 were considered as efficient P-responding genotypes. From GGE biplot, ICGV 06146 under P-deficient and TAG 24 under both P-sufficient and deficient conditions are portrayed as best performer. ICGV 06146 was identified as stable pod yielder and a promising genotype for P-deficient soils. The genotypes identified in this study can be used as a parent in developing mapping population to decipher the genetics and to devleop groundnut breeding lines suitable to P-deficient soils
Determinants of Agropastoralist Households’ Fodder Accessibility and Rangeland Conservation in Magu District, Tanzania
Get PDFThe availability and accessibility of adequate and quality fodder is a huge challenge for pastoral and agropastoralist communities in Tanzania. Fodder scarcity, primarily driven by rangeland degradation, pop- ulation growth, and climatic changes, limits livestock productivity and deepens rural poverty. This study assessed factors influencing agropastoralists’ access to fodder and their willingness to conserve fodder sources in Magu District, Tanzania. A total of 210 agropastoralist households were surveyed in three wards covering six villages. The results show that access to fodder during the wet season is positively influenced by a household’s income, land size, number of livestock, and physical capital. Dry season fod- der accessibility is negatively influenced by households’ land size, physical capital, and the number of livestock. Results also show that more than 60% of the agropastoral households accessed fodder sources formally (legally) in open areas, while 35% accessed fodder informally (illegally) in traditionally reserved highland areas, people’s farms, and restricted urban areas. Conservation of rangelands and fodder sources is positively influenced by a head of households’ level of education and income, and only 40% of house- holds participated in conservation of rangelands and fodder sources. Improved land tenure, education, and income diversification can improve households’ access to fodder and their willingness to conserve fodder sources
Upscaling Groundnut Seed Production and Delivery through Long-Term Public–Private and Development Organization Partnerships: Experiences from Tanzania
Get PDFMaking quality seed of improved legume varieties sustainably available and accessible to farmers in a timely manner and at affordable price is a major challenge in sub-Saharan Africa (SSA). Overcoming this challenge requires collective and long-term action through public–private and development organization partnerships (PPDOPs). The PPDOP model was tested by key seed system actors under the Tropical Legumes (TL) and Accelerated Varietal Improvement and Seed Delivery
of Legumes and Cereals in Africa (AVISA) projects from 2008 to 2021. The study used the case of groundnut in Tanzania to assess the role played by long-term PPDOPs in groundnut seed production and delivery systems. The effectiveness of seed production and delivery models of the various actors involved in the TL and AVISA projects was analyzed. The study used secondary data obtained from annual reports, unpublished and published literature, and institutional websites. The PPDOP model brought about significant changes to the seed systems. It was found that sustained seed production and delivery over a decade enhanced the performance of the groundnut value chain in Tanzania.
Under the TL and AVISA projects, a total of 49,046 tons of groundnut from different seed classes were produced through PPDOPs, covering an estimated 613,078 hectares with improved groundnut varieties. The intervention reached 45,201 stakeholders through 3048 demonstration plots, 128 field
days, 55 seed fairs, and 8147 tons of small seed packs of 1–5 kg. The study recommends the use of long-term PPDOPs in seed production and delivery systems for greater impacts on increased variety adoption and consistent seed supply and availability in SSA. Long-term PPDOPs ensure proper
coordination, open communication, clear accountability, solid trust, and standardized practices among actors in seed production and delivery systems
Smart reprograming of plants against salinity stress using modern biotechnological tools
Get PDFClimate change gives rise to numerous environmental stresses, including soil salinity. Salinity/salt stress is the second biggest abiotic factor affecting agricultural productivity worldwide by damaging numerous physiological, biochemical, and molecular processes. In particular, salinity affects plant growth, development, and productivity. Salinity responses include modulation of ion
homeostasis, antioxidant defense system induction, and biosynthesis of numerous phytohormones and osmoprotectants to protect plants from osmotic stress by decreasing ion toxicity and augmented reactive oxygen species scavenging. As most crop plants are sensitive to salinity, improving salt tolerance is crucial in sustaining global agricultural productivity. In response to salinity, plants trigger stress-related genes, proteins, and the accumulation of metabolites to cope with the adverse consequence of salinity. Therefore, this review presents an overview of
salinity stress in crop plants. We highlight advances in modern biotechnological tools, such as omics (genomics, transcriptomics, proteomics, and metabolomics) approaches and different genome editing tools (ZFN, TALEN, and CRISPR/Cas system) for improving salinity tolerance in plants
and accomplish the goal of “zero hunger,” a worldwide sustainable development goal proposed by the FAO