International Crops Research Institute for the Semi-Arid Tropics
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Institutional and technological innovations for sustained change in smallholder irrigation schemes in southern and Eastern Africa
Get PDFWater management systems must become more adaptable to alleviate projected shortfalls. Integrated socio-institutional and technological interventions are required to generate sustained change in irrigation water management and the profitability for smallholders and their schemes. We illustrate this by conducting an ex-post analysis of the ‘Transforming Irrigation in Southern Africa’ (TISA) project, which was implemented in two phases from 2013 to 17 and 2017–2023. The project introduced institutional and technological innovations to smallholder irrigation schemes in Tanzania, Mozambique and Zimbabwe: Agricultural Innovation Platforms as a participatory approach to engage farmers and stakeholders; and soil moisture monitoring tools to support farmer learning. We hypothesised that these innovations, despite differing socioeconomic and biophysical conditions in the three countries, would work synergistically to improve farmers’ adaptive capacity and generate sustained change. In this paper, we test our hypotheses through a synthesis of peer-reviewed TISA literature, focussing on four smallholder irrigation schemes and five factors identified in the literature as critical for increasing farmers’ adaptive capacity. Drawing predominantly on household surveys administered at the beginning, middle and end of the TISA project, we analyse a set of relevant indicators linked to the five factors. In addition to many changes, we found changes in irrigation management, including a reduction in total water use to less than half pre-TISA levels. Further, the changes were sustained when the schemes transitioned from an intensive research-for-development phase into a more operational phase. This research also shows that when governments listen to farming communities and revise institutional arrangements, such as water scheduling and scheme constitutions, this fosters more sustainable irrigated agriculture. We conclude that when initiating development projects for sustained change within smallholder irrigation schemes policy makers and donors must commit sufficient project time and funding for both a development phase and a transition to an operational phase. Programs must take a participatory approach and support multiple interventions including both socio-institutional and technological interventions
Developing pangenomes for large and complex plant genomes and their representation formats
Get PDFBackground
The development of pangenomes has revolutionized genomic studies by capturing the complete genetic diversity within a species. Pangenome assembly integrates data from multiple individuals to construct a comprehensive genomic landscape, revealing both core and accessory genomic elements. This approach enables the identification of novel genes, structural variations, and gene presence-absence variations, providing insights into species evolution, adaptation, and trait variation. Representing pangenomes requires innovative visualization formats that effectively convey the complex genomic structures and variations.
Aim
This review delves into contemporary methodologies and recent advancements in constructing pangenomes, particularly in plant genomes. It examines the structure of pangenome representation, including format comparison, conversion, visualization techniques, and their implications for enhancing crop improvement strategies.
Key scientific concepts of review
Earlier comparative studies have illuminated novel gene sequences, copy number variations, and presence-absence variations across diverse crop species. The concept of a pan-genome, which captures multiple genetic variations from a broad spectrum of genotypes, offers a holistic perspective of a species’ genetic makeup. However, constructing a pan-genome for plants with larger genomes poses challenges, including managing vast genome sequence data and comprehending the genetic variations within the germplasm. To address these challenges, researchers have explored cost-effective alternatives to encapsulate species diversity in a single assembly known as a pangenome. This involves reducing the volume of genome sequences while focusing on genetic variations. With the growing prominence of the pan-genome concept in plant genomics, several software tools have emerged to facilitate pangenome construction.
This review sheds light on developing and utilizing software tools tailored for constructing pan-genomes in plants. It also discusses representation formats suitable for downstream analyses, offering valuable insights into the genetic landscape and evolutionary dynamics of plant species. In summary, this review underscores the significance of pan-genome construction and representation formats in resolving the genetic architecture of plants, particularly those with complex genomes. It provides a comprehensive overview of recent advancements, aiding in exploring and understanding plant genetic diversity
Data-driven strategies to improve nitrogen use efficiency of rice farming in South Asia
Get PDFIncreasing nitrogen use efficiency (NUE) in agricultural production mitigates climate change, limits water pollution and reduces fertilizer subsidy costs. Nevertheless, strategies for increasing NUE without jeopardizing food security are uncertain in globally important cropping systems. Here we analyse a novel dataset of more than 31,000 farmer fields spanning the Terai of Nepal, Bangladesh’s floodplains and four major rice-producing regions of India. Results indicate that 55% of rice farmers overuse nitrogen fertilizer, and hence the region could save 18 kg of nitrogen per hectare without compromising rice yield. Disincentivizing this excess nitrogen application presents the most impactful pathway for increasing NUE. Addressing yield constraints unrelated to crop nutrition can also improve NUE, most promisingly through earlier transplanting and improving water management, and this secondary pathway was overlooked in the IPCC’s 2022 report on climate change mitigation. Combining nitrogen input reduction with changes to agronomic management could increase rice production in South Asia by 8% while reducing environmental pollution from nitrogen fertilizer, measured as nitrogen surplus, by 36%. Even so, opportunities to improve NUE vary within South Asia, which necessitates sub-regional strategies for sustainable nitrogen management
How beneficial are seasonal climate forecasts for climate risk management? An appraisal for crop production in Tanzania
Get PDFUnderstanding growing period conditions is crucial for effective climate risk management strategies. Seasonal climate forecasts (SCF) are key in predicting these conditions and guiding risk management in agriculture. However, low SCF adoption rates among smallholder farmers are due to factors like uncertainty and lack of understanding. In this study, we evaluated the benefits of SCF in predicting growing season conditions, and crop performance, and developing climate risk management strategies in Kongwa district, Tanzania. We used sea surface temperature anomalies (SSTa) from the Indian and Pacific Ocean regions to predict seasonal rainfall onset dates using the k-nearest neighbor model. Contrary to traditional approaches, the study established the use of rainfall onset dates as the criterion for predicting and describing growing period conditions. We then evaluated forecast skills and the profitability of using SCF in crop management with the Agricultural Production System sIMulator (APSIM) coupled with a simple bio-economic model. Our findings show that SSTa significantly influences rainfall variability and accurately predicts rainfall onset dates. Onset dates proved more effective than traditional methods in depicting key growing period characteristics, including rainfall variability and distribution. Including SCF in climate risk management proved beneficial for maize and sorghum production both agronomically and economically. Not using SCF posed a higher risk to crop production, with an 80% probability of yield losses, especially in late-onset seasons. We conclude that while SCF has potential benefits, improvements are needed in its generation and dissemination. Enhancing the network of extension agents could facilitate better understanding and adoption by smallholder farmers
Critical reflections on transforming smallholder irrigation systems from dysfunctional to functional climate smart agricultural systems
Get PDFSmallholder irrigation schemes are complex socio-ecological systems and critical components of agri-food systems. However, they are often driven by political objectives, including the production of staple food for food security and sovereignty, and therefore contrary to individual farmers’ aspirations of developing profitable farming enterprises that can adequately support scheme maintenance. This has resulted in dysfunctional schemes with rehabilitation efforts focused on infrastructure refurbishment, which neglect other critical aspects required for successful functioning such as strong market linkages and improved social dynamics. The poor performance of smallholder schemes represents a failure to enhance the livelihoods and food security of households and the development of local economies (Pittock et al., Citation2020). This failure creates an imperative to transform schemes using multiple interventions as leverage across the system to improve farmers’ adaptive capacity and enable schemes to become climate smart agricultural systems. This imperative is made more important because of the significant investment being made by governments and donors in irrigated agriculture
Links between protein-source diversity, household behavior, and protein consumption inadequacy in the Indian rural semi-arid tropics
Get PDFOur study analyzes the determinants, sources, and levels of protein consumption among 785 households across nine districts in six Indian states in the semi-arid tropics. We found that 80% of these households consumed less protein than recommended and relied on cereals for 60–75% of their protein intake. Notably, even when protein-rich foods are accessible to households, they still consume them insufficiently. We found that their protein intake deficiency is driven by a lack of diversity of protein sources (in particular, legumes, millets, and livestock), as well as by a dearth of women's education and role in household decision-making and low incomes and assets. We advocate for initiatives to raise nutrition awareness, empower women, and adopt a nutrition-centric farming approach
Lower vicine content reduces the reproductive yield performance in faba bean (Vicia faba L.)
Get PDFFaba bean is a nutritionally and medicinally rich popular legume crop. However, vicine-convicine remain as potential threats for “favism” in human beings. In this study, 189 diverse faba bean accessions have been evaluated for yield component traits and vicine content in seeds followed by a correlation study. Combined genetic variability analysis shows that traits like days to pod initiation (DPI), pod length (PL), test weight (TW) and grain yield have minimally been influenced by the environment. PCA revealed that TW, PL and PW were the primary indicators for deciding yield performance. LC–MS/MS confirms that vicine concentration varied in between 3.489 and 10.025 g/kg and a significant positive correlation (0.40***) was observed between vicine conc. and grain yield of faba bean. Thus, present study demonstrated that the faba bean genotypes containing lower vicine were mostly poor yielding, which might be regulated by vicine in faba bean. Therefore, complete elimination of vicine or development of near-zero vicine faba bean could drastically reduce the yield potential of the crop, hence one has to be very cautious and follow efficient selection strategies while optimizing lower concentration of vicine for development of low vicine varieties. This study shows that faba bean genotypes containing 4.0–5.5 g/kg vicine were fairly productive and also have considerably lower vicine
Transpiration efficiency variations in the pearl millet reference collection PMiGAP
Get PDFTranspiration efficiency (TE), the biomass produced per unit of water transpired, is a key trait for crop performance under limited water. As water becomes scarce, increasing TE would contribute to increase crop drought tolerance. This study is a first step to explore pearl millet genotypic variability for TE on a large and representative diversity panel. We analyzed TE on 537 pearl millet genotypes, including inbred lines, test-cross hybrids, and hybrids bred for different agroecological zones. Three lysimeter trials were conducted in 2012, 2013 and 2015, to assess TE both under well-watered and terminal-water stress conditions. We recorded grain yield to assess its relationship with TE. Up to two-fold variation for TE was observed over the accessions used. Mean TE varied between inbred and testcross hybrids, across years and was slightly higher under water stress. TE also differed among hybrids developed for three agroecological zones, being higher in hybrids bred for the wetter zone, underlining the importance of selecting germplasm according to the target area. Environmental conditions triggered large Genotype x Environment (GxE) interactions, although TE showed some high heritability. Transpiration efficiency was the second contributor to grain yield after harvest index, highlighting the importance of integrating it into pearl millet breeding programs. Future research on TE in pearl millet should focus (i) on investigating the causes of its plasticity i.e. the GxE interaction (ii) on studying its genetic basis and its association with other important physiological traits
Genetic diversity analysis of Azerbaijani bread wheat (Triticum aestivum L.) genotypes with simple sequence repeat markers linked to drought tolerance
No full textWater stress causes large agricultural losses worldwide and deteriorates its quality. Drought tolerance in plants is a complex trait governed by multigenes and infleunce of various environmental factors affecting the expression of these genes. Thus this complexity necessitates the application of new molecular methods to identify and develop drought tolerant genotypes. The present study was conducted to investigate the genetic diversity of 45 Azerbaijani wheat (Triticum aestivum L.) core collection genotypes utilizing simple sequence repeat (SSR) markers associated with drought tolerance. Our results showed that nine primers out of twelve showed polymorphism. Maximum number of alleles were detected for WMC177 marker (on chromosome 2A), WMC 264 (on chromosome 3A) and WMC219 (on chromosome 4A) with 5, 5 and 4 alleles, respectively. The lowest alleles were determined for WMC219 marker (chromosome 4A) with only one allele. The total number of the detected alleles on A and D genome was 18 and 11 respectively. The maximum number of unique bands (3) was scored with pimer WMC 177. Seven genotypes (cv Gobustan, and Gizil bugda, landrace 6262, and research materials 6170, 6286, 6296 and 6293) possessed unique bands. Based on polymorphism analysis of the wheat genotypes by SSR markers, drought tolerant genotypes for utilization in breeding programs were selected
Soil property and crop yield responses to variation in land use and topographic position: Case study from southern highland of Ethiopia
Get PDFUnderstanding soil property and crop yield responses to variations in land use and topographic gradient is vital for designing targeted soil and agronomic management practices. This study investigated the interrelationships between land use, topographic position, soil properties, and crop yield. Three replicates of three land use types - enset agroforestry, cropland (annual crop), and grazing land - were selected along a toposequence (upper, middle and lower) for the study. A total of 54 composite soil samples were collected and analyzed. Grain yield and above ground biomass were also gathered from the cropland and analyzed. Soil profile descriptions revealed notable variations in soil physical properties, including soil texture, bulk density, color, horizons, and depth among the pedons of the three topographic positions. Clay and silt fractions exhibited significant differences between land uses and topographic positions, while the sand fraction was influenced by topographic position alone. Crop and grazing lands displayed higher clay content compared to the enset field. A decreasing trend in clay fraction was observed from upper to lower topographic positions. The enset field had significantly higher soil pH, OC, TN, and K+ contents than crop field. A significantly higher available P of 16.61 mg kg−1 was measured from lower slope position followed by 14.08 mg kg−1 in middle slope. The upper slope position had the highest exchangeable acidity of 3.09 cmol(+) kg−1), followed by middle slope with 2.77 cmol(+) kg−1), 2.45 cmol(+) kg−1) in the lower slope position. Grain yield and above ground biomass decreased from lower slope to middle slope and upper slope positions. These observed variations in soil properties and crop yield among land uses and topographic positions underscore the necessity for tailored soil management strategies and agronomic practices specific to land use types and the specific localized topographic conditions to optimize agricultural productivity