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Unveiling yellow rust resistance in the near-Himalayan region: insights from a nested association mapping study
No full textThe global spread of yellow rust has posed a significant threat to wheat production, making the identification of novel resistance-conferring genetic loci crucial. The near-Himalayan region has been proposed as the pathogen's origin and is characterized by strong and diverse disease pressure. Even though this makes wheat varieties from this region likely to harbor resistance, Asian germplasm has been highly underrepresented in modern breeding. To explore this potential, we screened an Asian nested association mapping (NAM) population comprising traditional and modern wheat varieties under artificial epidemics in multiple field trials. Combined quantitative trait locus (QTL) mapping revealed the two resistance genes Lr67/Yr46/Sr55 and Lr34/Yr18/Sr57, as well as two potentially novel yellow rust resistance loci. The resistant allele of the first one, located on chromosome 3D, is unique to a traditional variety from Nepal, while the second one, found on chromosome 5B, is present in several NAM families. The broad geographic distribution of this QTL across regions with high disease pressure suggests it may serve as a durable source of resistance. Strong observed resistances were conferred by a combination of several resistance loci, suggesting the stacking of resistances as a successful strategy in yellow rust hotspot areas
Unveiling native mycorrhizal fungi diversity: insights into growth performance, nutrient uptake, and root system robustness in caper-bush (Capparis spinosa L.) seedlings
No full textThis study investigates the role of native arbuscular mycorrhizal fungi (AMF) in enhancing the growth performance, nutrient uptake, and root system robustness of caper bushes (Capparis spinosa L.), a key species for rehabilitating marginal lands in the Mediterranean region. The primary aim is to identify AMF communities in the rhizosphere soils of caper bushes and evaluate their effects on seedling growth and nutrition. Greenhouse experiments were conducted over two years in Morocco's Safi region, using two seedling groups: one inoculated with a newly identified native AMF complex, and another uninoculated (control) group. Numerous AMF morphotypes were discovered in the rhizospheric soils under mature caper-bush plants, predominantly from the Glomus genus. Soil analysis revealed a sandy loam texture and high alkalinity. Results showed that AMF inoculation significantly enhanced plant biomass (similar to 135 %), root length (similar to 58 %), and the number of secondary roots (similar to 141 %) compared to controls. Mycorrhizal dependency was approximately 58 %. Furthermore, inoculated plants showed substantial improvements in mineral nutrient levels: potassium (K+), calcium (Ca2+), phosphorus (P), magnesium (Mg2+), iron (Fe2+), and zinc (Zn2+), with increases ranging from similar to 1.5 to similar to 3 times that of non-inoculated plants. The fresh and dry weights of mycorrhizal plants also increased by similar to 87 % and similar to 135 %, respectively. Additionally, the specific absorption rates for these nutrients were enhanced, with increases ranging from similar to 7 % to similar to 170 %. These results highlight pre-transplant AMF inoculation as a promising strategy to enhance caper-bush growth and nutrition in challenging environments. Future research should focus on optimizing AMF inoculation for caper-bush cultivation and exploring its potential for land restoration
Intercrop overyielding is maintained under estimated water and nitrogen stress in maize-cowpea on-farm trials in semi-arid Zimbabwe
No full textProblem: Semi-arid regions of sub-Saharan Africa are characterized by highly variable rainfall and low inherent soil fertility. Maize-cowpea intercropping may offer the prospect of increasing and stabilizing crop productivity in these regions. However, the performance of such cropping systems often varies considerably in space and time. Objective: The main objective of the study was to understand how farmer context and rainfall variability influence the performance of maize-cowpea intercropping, using on-farm field experiments together with soil-crop model simulations to compute water and nitrogen stress. Methods: The data used in this study was generated from twelve on-farm trials during two cropping seasons (2021/22 and 2022/23) in semi-arid Zimbabwe. Three maize (Zea mays L.) varieties, one cowpea (Vigna unguiculata (L.) Walp.) variety and two cropping systems - either sole or intercropped - were tested. The STICS soil-crop model was parameterized to reproduce crop growth in the on-farm trials and compute water and nitrogen (N) stresses. Linear mixed-effects models were used to assess the impact of experimental treatments and simulated water and N stresses on intercropping performance. Results: The Partial Land Equivalent Ratio (pLER – the ratio of intercropped productivity over sole crop productivity) for maize and cowpea greatly varied across farms and crop types. Maize variety did not significantly impact the pLER of maize and cowpea. Water stress and nitrogen (N) stress simulated by the model were significant predictors of variations in pLER: maize pLER for aboveground biomass significantly decreased with increasing simulated water stress, and maize pLER for grain yield significantly decreased with increased simulated N stress. Yet, average LER remained above one, regardless of the water or N stress on maize, because of a greater contribution of cowpea to LER when water and N stress on maize was high. Late planting was found to exacerbate maize water stress, while low total nitrogen in the top soil was significantly correlated with maize nitrogen stress. Conclusion: Our study reveals that the production benefits of maize-cowpea intercropping can be maintained, in conditions of high water and nitrogen stress in multi-year and multi-location on-farm experiments. Implications: Our findings confirm the assumption that intercropping is a useful approach to intensify and stabilize grain and fodder production in smallholder mixed crop-livestock farming systems in semi-arid environments
Fertilizer, soil health, and economic shocks: a synthesis of recent evidence
No full textMost countries, at all stages of development, adopt policies to improve agricultural productivity through the application of inorganic fertilizer and the management of soil health. Unfortunately, global and local economic shocks can quickly erode the impact of these policies, as was evident during the global food, fuel, and fertilizer price crisis that began in 2020. This paper synthesizes recent evidence on the magnitude and distribution of-and responses to- the recent shocks to international fertilizer markets, building on evidence from this Special Issue of Food Policy and other recent contributions to the literature. The available evidence suggests that although international fertilizer prices increased dramatically in 2020-2022 and remained above their pre-COVID-19 pandemic level through 2024, the medium-term effects on global fertilizer demand were relatively modest. However, global aggregates obscure important short-term effects, including reduced fertilizer use and lower farm profits in smallholder production systems in many low- and middle-income countries. Although these effects varied considerably by country, dependence on fertilizer imports and vulnerability to idiosyncratic domestic shocks likely played a key role in driving these effects. The evidence synthesized in this paper reveals varying responses (across countries and farmers) and patterns of price transmission (across local and international markets) while also highlighting the potential of fertilizer subsidy programs and other policy interventions to mitigate the effects of fertilizer price volatility and improve soil health, particularly in the midst of a climate crisis that adds uncertainty to agricultural production. From a longer-term perspective, much research is still needed to unpack the effects of this crisis-and the possible effects of future crises-on the international transmission of fertilizer price shocks, policy response options to both immediate shocks and more protracted threats, farm-level strategies to increase resilience to these shocks and to encourage more judicious fertilizer use and soil health management
Empowering farmers with digital El Niño advisories: Insights from Malawi and Zambia
No full textClimate extremes, including droughts, floods, and cyclones, are becoming increasingly frequent, severe, and geographically extensive in Southern Africa, with devastating effects on populations heavily reliant on rain-fed agriculture and broader economies. Farmers urgently need guidance and support to build resilience against climate-related disasters. However, the national extension systems in the region lack adequate funding and the capacity to respond promptly and effectively during emergencies. This report analyzes a digital advisory campaign aimed at disseminating awareness and advisory messages to farmers during an El Niño event across Malawi and Zambia, leveraging Interactive Voice Response (IVR) technology accessible via basic, non-smart mobile phones. The campaign was rolled out in December 2023, prior to the start of the 2023/24 season. Our report builds on farmer feedback, particularly on how useful they found the campaign, their livelihood outcomes in the aftermath of the El Niño, and other notable trends in the data. The campaign reached over 1 million farmers in the two countries, with more than 90% of respondents finding the messages useful for awareness and preparedness. Both in Malawi and Zambia, radio emerged as the most popular channel for receiving extension messages. Moreover, results also confirmed that meteorological forecasts played a critical role in influencing farmers’ choices of crop and planting dates. For instance, dry spells of more than 21 days led to maize yield losses of 70-90%. Results further indicate that conservation agriculture and the adoption of drought tolerant crops were the most popular mitigation measures employed by farmers. The findings suggest that governments need access to appropriate information about the circumstances of their population to make informed decisions about how to efficiently extend support. Digital advisories provide an opportunity to gather real-time data on farmer conditions and can be used to deploy support. Additionally, post-event analysis provides valuable evidence that can be used to enhance the design of future response interventions and reduce donor dependence.22 page
Culture of impact in agricultural research organisations: What for and how?
No full textResearch organisations experience increasing demands to analyse on the multidimensional societal impacts of their activities. This leads to more reflections about the integration of organisational strategies devoted to research evaluation and impact monitoring, in order to answer societal and funder's demands, improve research practices, and make research and innovations more transformative to society. Establishing a “culture of impact” within an organisation is driven by multiple factors and translates into a variety of changes at different organisational levels. We aim to understand what motivates agricultural research organisations to develop a culture of impact, and the consequences of this culture on research, management, and collaboration practices. For this, we analyse organisational trajectories of three research organisations: the French Agricultural Research Centre for International Development (Cirad), the Brazilian Agricultural Research Corporation (Embrapa), and the Colombian Agricultural Research Corporation (AGROSAVIA). Through a cross-analysis of these cases along the reasons to integrate impact evaluation in strategic agendas, the materialisation of a culture of impact in practice, and what it entails in terms of cognitive and practical changes within their respective staff and management structures, we highlight drivers and patterns of development of a culture of impact, and circumstances that seem to either favour or hinder its emergence. This study is unique for examining various types of changes that a culture of impact can generate among individuals, in particular. It offers valuable material to enable re-interrogate and orient a research organisation's culture of impact's path in accordance with organisational values, priorities, and opportunities
The fungal and protist community as affected by tillage, crop residue burning and N fertilizer application
No full textThe bacterial community in soil is often affected by agricultural practices, but how they affect protists and fungi is less documented. Soil from treatments that combined different N fertilizer application rates, tillage and crop residue management was sampled from a field trial started by the International Maize and Wheat Improvement Center (CIMMYT) at the ‘Campo Experimental Norman E. Borlaug’ (CENEB) in the Yaqui Valley in the northwest of Mexico in the early 1990s, and the fungal and protist community determined. Tillage, residue burning, and N fertilizer application had no significant effect on the fungal and protists alpha diversity expressed as Hill numbers and no significant effect on the fungal and protist community structure considering all species. The relative abundance of plant pathogens and undefined saprotrophs as determined with FUNGuildR increased significantly with tillage, while that of dung-plant and dung-soil saprotroph, and plant pathogens by burning (P < 0.05). It was found that the protists and fungal community structures were not altered by different agricultural practices, but some fungal guilds were, i.e., plant pathogens and saprotrophs, which might affect soil organic matter decomposition, nutrient cycling and crop growth
Sorghum production in selected states of Sudan during the 2024/25 growing season
No full textThe crop assessment work presented in this report focuses on monitoring the area, yield, and production of sorghum planted during the 2024/25 growing season. Our analysis covers the states of Gedaref, White Nile, Blue Nile and the New Halfa irrigation scheme in Kassala, which are Sudan’s main surplus sorghum producers. Sorghum is Sudan’s staple crop and has been referred to as a banking alternative because it can be safely stored for more than a year in underground pits called Matmuras. For the analysis, we first used satellite data to identify areas (pixels in the satellite images) grown with sorghum. Next, we related the peak normalized difference vegetation index (Peak-NDVI) with yield data obtained from crop cuts. In the last step, we applied the resulting regression line to all sorghum areas. The major insights from the report include the following: • Crop conditions were better than expected despite the many challenges farmers faced in 2023/24; • Sorghum planted area in 2023/24 i Gedaref was slightly higher than in 2023. It was also higher than the long-term average in White Nile and Kassala, while it was below average in Blue Nile • For Kassala, we were only able to generate an area estimate, which was 734,000 ha. • The 2024/25 state level average productivity of rainfed sorghum was around 0.9 t/ha; • The 2024/25 estimated total sorghum production was 2.65 million t (by state: Gedaref, 1.57; White Nile, 0.70; Blue Nile, 0.31 and New Halfa irrigation scheme in Kassala 0.07 million t).21 page
Data-driven strategies to improve nitrogen use efficiency of rice farming in South Asia
No full textIncreasing 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.22–3
Validating a novel genetic technology for hybrid maize seed production under management practices associated with resource-poor farmers in Zimbabwe
No full textSocietal Impact Statement. A hybrid maize seed production technology has the potential to reduce the complexity of hybrid seed production and increase seed quality. Here, we investigate the potential impact of this technology on yields when hybrid maize is recycled. Hybrid maize recycling is a practice used by resource-poor farmers as a coping mechanism during drought years. Recycling hybrid maize produced using this technology could provide a small yet significant yield benefit to resource-poor farmers when they chose to recycle. This study provides an example of how social considerations can be incorporated into testing strategies of new technologies to ensure equitable benefits. Summary. Understanding the performance of new genetic technologies in farmers' real-world realities, especially those relevant to resource-poor farmers, is often overlooked but is essential to ensure equitable benefits. A new genetic technology was developed to simplify hybrid maize seed production in sub-Saharan Africa, thereby improving farmers' access to high-quality hybrid seed. Hybrids produced with this technology segregate 50:50 for pollen-producing and non-pollen producing and are designated 50% non-pollen producing (FNP). FNP maize has higher yields in low-input environments. As recycling hybrid maize seed remains a common practice in Zimbabwe, including among resource-poor households, it is important to understand the impact of recycling FNP seed on the yield gains from the FNP technology. The potential impact of recycling FNP hybrid seed was assessed by testing three seed recycling scenarios on-station and on-farm. The extent of hybrid seed recycling and the types of households recycling hybrid maize seed over a 3-year period were also investigated. Hybrid maize seed recycling was associated with resource-poor farmers, although it was not continually practiced across years. Yield gains associated with FNP were retained under recycling practices, albeit reduced. The greatest yield benefit was when seed from only non-pollen-producing plants was used. Yield gains were associated with longer ears and more kernels per ear. While recycling hybrid maize seed reduces potential yields due to inbreeding depression, in the years when farmers cannot afford to plant hybrid maize only, recycling non-pollen-producing hybrid maize seed conferred a yield benefit of 116 kg ha−1.801-81