Ensuring sustainable crop production when yield gaps are small: A data-driven integrated assessment for wheat farms in Northwest India

Northwest India achieved remarkable wheat productivity gains during the past decades. However, this has been accompanied by increasing input levels and intensive production practices, raising questions about the economic and environmental sustainability of current cropping systems. A multicriteria integrated assessment is required for wheat farms in the region to understand the scope for cleaner wheat production in the future. Production practices from irrigated wheat fields (n = 3928) were evaluated for multiple sustainability indicators, namely yield gap, nitrogen (N)-use efficiency, profitability, and greenhouse gas emissions. Stochastic frontier analysis was combined with simulated potential yield (Yp) data to identify the causes of wheat yield gaps in the region. N-use efficiency was estimated by calculating the partial factor productivity of N, profitability was computed based on reported input-output amounts and prices, and greenhouse gas emissions were quantified using the Mitigation Options Tool (MOT). These indicators were subjected to a multicriteria assessment using the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) under different scenarios (i.e., different weights for different indicators). For each scenario, farmers’ fields were classified as most efficient, efficient, less efficient, and least efficient, and random forest was used to identify the most important management practices governing the field classification. Wheat yield gaps were small (25–30 % of Yp or 2.4 t ha−1) and mostly attributed to the technology yield gap (ca. 20 % of Yp or 1.5 t ha−1). Ranking and grouping the farmers’ fields in the scenario with equal weights for all indicators revealed that at least 25 % of the fields had very high greenhouse gas emissions (>1500 kg CO2-eq ha−1) at a productivity level of 80 % most efficient fields adopting zero tillage) to achieve an overall objective of higher yield, lower greenhouse gas emissions, more profit and higher N-use efficiency, whereas residue retention and tillage intensity would need to be prioritized for minimizing greenhouse gas emissions. For the most efficient fields the decrease in greenhouse gas emissions was always associated with a decline in yield level. The most important management practices governing the field classification included the crop establishment method used for the previous rice crop, the number of tillage operations, residue retention, and the N fertilizer rate for wheat. The study provides a data-driven approach to screen trade-offs between performance indicators and to identify the management practices that can deliver sustainable and cleaner crop production in the future

Molecular screening of septoria-resistant genes in historical Turkish bread wheat germplasm using the validated gene specific SSR markers

Septoria tritici blotch (STB), caused by Zymoseptoria tritici, poses a significant threat to global wheat production, particularly in T & uuml;rkiye. Resistance breeding is the most sustainable and effective disease control method. Molecular markers, especially simple sequence repeat (SSR) markers are extensively employed in wheat breeding to enhance the efficacy. The primary objective of this study was to identify Stb resistance genes among 143 historical registered Turkish bread wheat genotypes released as commercial cultivars between 1963 to 2014, using 16 closely linked SSR markers. The findings revealed substantial genetic variation among the screened cultivars, with the Stb3 gene being the most prevalent, identified in 89.51% of the samples. Other notable resistant genes included Stb13 (71.32%), Stb4 (43.33%), and Stb11 (41.25%). Cultivars Porsuk-2811, Porsuk-2853, and Porsuk-2868 exhibited the highest level of resistance to STB, with 10 resistance genes detected. Of the 143 cultivars screened, 10 were found to carry a total of nine Stb genes, while two cultivars were observed to possess only a single resistance gene. The study identified 23 wheat cultivars harboring 8-10 Stb resistance genes, which are highly recommended for future wheat breeding programs and gene pyramiding strategies to combat Z. tritici. This research provides critical insights for national breeding programs, supporting the development of resilient and high-yielding wheat varieties resistant to STB.89-10

Harnessing phosphocompost extracts to mitigate Meloidogyne javanica impacts on tomato

This study evaluated the chemical properties of phosphocompost extracts and their effectiveness in inducing tomato seedlings resistance to Meloidogyne javanica. Phosphocomposts: Sugar beet phosphocompost (PC-SB: CP2), green waste phosphocompost (PC-GW: CP3), and olive mill waste phosphocompost (PC-OMW: CP4), were utilized to produce compost water extracts at concentrations of 1:5, 1:10, 1:20, and 1:100 g:mL and then applied as soil drenches for tomato seedlings one-week post-inoculation. The CP2 extract applied at a 1:5 dilution led to marked improvements in growth parameters, with plant height increasing by over 52.2%, shoot fresh biomass rising by approximately 52.44%, and shoot dry biomass showing a gain of 62.21%. Root biomass also rose by 33%. Chlorophyll a increased with CP4 at 1:5 and 1:100 (41.05% and 37.32%), chlorophyll b increased with CP3 at 1:5 and 1:10 (22.34% and 7.59%), while carotenes showed no variation. Polyphenols rose by 86.45-91.01% with CP2 from 1:5 to 1:20, and flavonoids increased by 64.90% with CP4 at 1:10. CP2 diminished the ultimate M. javanica population and reproduction factor by 171.43%, while CP4 at 1:20 decreased egg masses by 151.94%. The root gall index showed no variation. The chemical composition of phosphocomposts revealed that the strategic incorporation of diverse organic improvers (10%) in phosphocomposts yielded distinct nutrient signatures, with sugar beet waste enhancing PO43- (12.91 mg/L) and secondary macronutrients, green waste optimizing NO3- (69.91 mg/L) and SO42- (62.70 mg/L) availability, and olive mill waste producing superior micronutrient concentrations alongside dominant Ca (24.21 mg/L), K (392.50 mg/L), and P (9.17 mg/L) levels. Overall, the results underscore the potential of phosphocompost extracts as a viable, low-cost, and eco-friendly alternative to synthetic nematicides, offering a sustainable and resilient approach to M. javanica control while enhancing tomato plant growth

A retrospective analysis of maize performance under low nitrogen stress conditions in sub-Saharan Africa

Introduction: Fertilizer use in sub-Saharan Africa (SSA) is the lowest in theworld and has stagnated. Consequently low nitrogen (N) stress is one of the principal constraints to maize yields in this region. Therefore improving nitrogen use efficiency of maize varieties will result in higher nitrogen recovery rates, leading to less leaching of nitrogen as well as loss through nitrification and ammonification. This study aimed to: 1) Investigate the relationship between grain yield under low N and optimal conditions; and 2) Establish the level of variability in low N tolerance among elite Eastern and Southern African (ESA) maize varieties. Methods: Fifty-eight paired trials, each consisting of 40 to 65 maize hybrids, were conducted under low N and optimal (i.e.,high N) conditions in five countries, in Eastern and Southern Africa during 2013-2015. Results and discussion: The level of yield reduction as a result of low N stress ranged from 8% to 91% across the 58 paired trails. Grain yield of hybrids ranged from1.69Mg ha-1 to 3.44 Mg ha-1 in the early maturity group and 1.71 Mg ha-1 to 3.35 Mg ha-1 in the intermediate to late maturity group, with heritability ranging from 0.25 to 0.53 and 0.29 to 0.76, in the respective two maturity groups. Under the low N stress. Pre-commercial hybrids that were bred for low N tolerance performed better than the old commercial hybrids and open pollinated varieties (OPVs). These results suggest that if more effort is devoted to selecting maize under low N conditions, significant yield gains can be realized with profound impact on maize productivity in SSA

How has scientific literature addressed crop planning at farm level: A bibliometric-qualitative review

Crop planning (CP), being the core of farm management and decision-making, remains significant as the selection and allocation of appropriate crops determine the economics and sustainability of farming system. A systematic literature review was conducted to obtain a structural overview and consolidate the knowledge from CP literature, given the dearth of review articles in this domain. The methodology included systematic selection of literature in phases and mixed-method systematic review process consisting of bibliometric analysis and qualitative review. This enabled an understanding the main characteristics of CP literature and answer how CP has been addressed at farm level. 1516 publications were selected in first phase after which 652 were screened using bibliometric analysis software, VOSviewer and CiteSpace, in second phase to identify research hotspots and recent trends. Optimization, irrigation, sustainability, adaptation were certain hotspots, while a shift in research trend was observed from decision support, crop allocation and bioenergy to climate change, water resources and big data. Last phase focussed on qualitative review of 31 publications on farm. Three broad themes of articles emerged namely "farmer's decision-making", "soil-water-agroecology" and "merits of innovative technologies". The study proposed several recommendations for small farming systems which were largely ignored in literature. These include factorial design for crop combinations, choices in options, estimation of crop diversity index and relative time- dispersion in yields. The current review produced a macroscopic overview of accumulated knowledge on CP and provided future directions to harness the unexplored potential in this field

A conceptual framework for the contextualization of crop model applications and outputs in participatory research

Contextualization of generic scientific knowledge to context-specific farmer knowledge is a necessary step in farmers’ innovation process, and it can be achieved using crop and farm models. This work explores the possibility to simulate a large number of scenarios based on farmers’ descriptions of their environment and practices in order to contextualize the discussion for each participating farmer. It presents a novel framework consisting of six actions divided in three phases, namely, phase I—reaching out to the farmers’ world: (i) project initialization; (ii) determination of the agronomical question anchored in farmers’ context; (iii) characterization of the environment, the management options, and the indicators to describe the system under consideration; phase II—within researchers’ world: (iv) crop model parametrization; (v) translation of model outputs into farmer-proposed indicators; and phase III—back to farmers’ world: (vi) exploration of contextualized management options with farmers. Two communication tools are created during the process, one containing the results of simulations to feed the discussions and a second one to create a record of it. The usefulness of the framework is exemplified with the exploration of soil fertility management with manure and compost applications for sorghum production in the smallholder context of Sudano-Sahelian Burkina Faso. The application of the framework with 15 farmers provided evidence of farmers’ and agronomists’ understanding of options to improve cropping system performance with better organic amendment management. This approach allowed farmers to identify and relate to the scenarios simulated, but highlighted interrogations on how to adapt the crop model outputs to particular situations. Though applied on issues related to tactical change at field level, the framework offers the opportunity to explore broader issues with farmers, such as farm reconfiguration

Unveiling the heterosis pattern of modern maize breeding in Southwest China through population structure and genetic diversity analysis

Maize (Zea mays L.) is an important food crop throughout the world and is also one of the earliest crops to use heterosis. In this study, we evaluated the genetic diversity, population structure, and selective sweep of 100 elite inbred maize lines collected from the current breeding program in Sichuan province, Southwest China, using 5,261,175 high-quality single nucleotide polymorphisms (SNPs). We discovered an abundance of genetic diversities and classified them into four groups. By combining kinship relationships, these groups were further divided into Tropic-local A, Improved-tropic, Tropic-local B, and Improved-local. Genomic differentiation was assessed using Fst values (0.21-0.44) as well as genetic diversity (pi = 6.07 x 10-4 - 6.61 x 10-4). We generated 900 (90 x 10) hybrids using 90 and 10 inbred maize lines from 100 diverse maize germplasms. All hybrids were evaluated for 10 traits in three replicate tests across two locations. We found that the patterns of G1 x G3, G1 x G4, G2 x G3, and G3 x G4 exhibited significant heterosis in yield-related traits and have been used in commercial breeding. In addition, we also explored the relationship between 10 traits of hybrid offspring and the number of heterozygous SNP. Under most heterosis modes, the best linear unbiased estimation (BLUE) value of the trait was highly consistent with the trend of deleterious SNPs, but there was a deviation in the G1 x G3 mode. Taken together, the results provide insight into the utilization of the current maize germplasm in Sichuan province to improve hybrid breeding

Macrofauna accelerates nutrient cycling through litterfall in cocoa agroforestry systems

This study aimed to better understand nitrogen (N), phosphorus (P), and potassium (K) cycling through litterfall in smallholder cocoa agroforestry systems and to assess if these nutrient flows can be measured using standard litterbags. Annual litter production, relative mass loss, and nutrient loss rates from cocoa leaf litter were evaluated in three farms in south-western Nigeria with and without macrofauna access. Litterfall was measured fortnightly close to the base of the cocoa tree and at the edge of the tree canopies from January 2020 to December 2021. Leaf litter decomposition rates were determined over 388 days in 2 mm mesh litterbags to exclude macrofauna and in frames open to the soil surface to allow macrofauna access. Concentrations of C, N, P, and K were measured in the remaining litter at 180, 244, 314, and 388 days after incubation. Annual estimates of litterfall (10.62 Mg DM ha−1) did not significantly differ between the traps close to and away from the cocoa tree trunk. Nutrient cycling from litter was estimated at approximately 101 kg N, 5 kg P, and 89 kg K ha−1 year−1. Relative litter decomposition rates (k) significantly differed between frames and litterbags. Macrofauna access significantly reduced the C:N ratio in the remaining litter and increased N and P loss from the litter layer by 28 and 69%, respectively. In conclusion, nutrient flows through litterfall are considerable, and N and P transfer rates to soil are likely underestimated in litterbag experiments that exclude macrofauna

Feeding a fast-growing population by 2050 through accelerated agricultural transformation: potential avenues for Ethiopia

In recent years, Ethiopia has recorded noteworthy progress in boosting agricultural productivity. Compared with many countries in Africa, Ethiopia’s achievement has been remarkable, especially considering the dire historical challenges, marked by the devastating famine in the 1980s. Despite notable strides in enhancing food production across the country, a significant segment of the population continues to face persistent food insecurity. The agricultural sector struggles to generate sufficient output to match the pace of population growth, facing challenges such as low yield, limited arable land, high population density intensified by persistently high fertility, environmental degradation, climate change, and water scarcity. Ethiopia stands at the forefront of Africa’s burgeoning population growth, with an estimated population of 213 million by mid-century, compared to 120 million people in 2023. In this chapter, we explore potential avenues for accelerated agricultural transformation. Our goal is to propose strategies that can enhance productivity, encourage off-farm employment opportunities, and augment agricultural output through value addition. We particularly emphasize the importance of land consolidation, inclusive structural changes in the agricultural sector, and a vibrant non-agricultural sector to absorb excess rural labour. Although this chapter primarily focuses on Ethiopia, we draw inferences and offer insights for other African countries where relevant.35-4

Tester selection for combining ability estimation of storage root yield and sweetpotato virus disease in sweetpotato breeding

General combining ability (GCA) is the major selection criterion for new sweetpotato (Ipomoea batatas) parents in a reciprocal recurrent selection (RRS) scheme. Here we aimed to estimate GCA and specific combining ability (SCA) by using 16 potential testers involved in an 8 x 8 partial diallel and propose a procedure to identify testers in sweetpotato breeding. Data on storage root yield in tons per hectare (rytha), and sweetpotato virus disease (vir2) from 64 families (1,913 clones) were collected in five trials at two locations in Uganda. The estimates of the female GCA accounted for the largest additive genetic variation for storage root yield compared to the male GCA for both traits. Mid-parent heterosis ranged from - 6.2 to 7% for rytha, and - 1.1 to 1.3% for vir2 in the progeny families. A stepwise procedure to identify testers top-ranked 'NASPOT 7' as a dual tester for both traits. Besides this parent, 'Ejumula' and 'NASPOT 10 O' for rytha, and 'NASPOT 1', 'NK259L', 'SPK004', and 'NASPOT 11' for vir2 are particularly suitable as respective single-trait testers. Testers are important in many plant breeding programs to enhance efficiency of RRS, and thus other crop species might benefit from the strategy and methods applied herein