Soil management

Conventional agriculture expansion and intensification are among the main causes of land degradation and soil biodiversity losses worldwide. Developing more sustainable approaches poses major challenges in large-scale agriculture, as it is the case in the Argentine Pampas, one of the largest agricultural regions in the world. Among soil biota, earthworms regulate soil organic matter dynamics, soil structure formation and maintenance, and create a habitat for numerous organisms, making them especially useful for assessing agricultural performance in terms of preserving soil biological processes. However, earthworm communities in ecologically based agricultural systems have been seldom studied in the region, and the role of farm-scale factors in shaping these communities remains even less understood. Thus, our aims were (1) to assess the effect of three different systems: large-scale ecologically based agriculture, large-scale conventional agriculture, and natural grasslands, on earthworm community attributes and composition; and (2) to understand which variables at the farm scale, related to management strategies and to regional and soil conditions, mostly shape earthworm communities in agricultural soils. We sampled earthworms in 54 sites representing the three systems. We characterized farms in terms of management practices and regional and soil conditions. We observed that ecologically based agriculture increased earthworm abundance, biomass and richness compared to conventional agriculture. However, geographic location played a more significant role in determining species identity than the system. Decreasing crop proportion and increasing non-cropped areas at the farm scale were the most important management practices positively affecting earthworms. This is one of the few studies in the Argentine Pampas to show that ecologically based, large-scale agriculture effectively benefits earthworm communities, and the first to identify how farm-scale factors influence them—particularly mixed farming and the maintenance of non-cropped areas within farms. We believe these findings offer strong encouragement for large-scale farmers to adopt more sustainable practices.

Escudero, H.J., Domínguez, A., Rodríguez, M.P. et al. Ecologically based agriculture benefits earthworms in Argentina’s large-scale systems: farm-level strategies matter. Agron. Sustain. Dev. 45, 50 (2025). https://doi.org/10.1007/s13593-025-01044-z

Reasoned increases in planting density are key measures to enhance maize yields. However, most existing studies on maize planting density based on long time spans often fail to account for diverse microclimates. The impact of planting density on yield components has not also been well investigated in major production regions of China. Therefore, we conducted a meta-analysis of 1951 data pairs from 160 published papers (2013–2023) to assess the effects of increasing planting density on maize yield, yield components, phenotypic traits, and resource utilization and to determine optimal density increase ranges for different environments. The results showed that increasing planting density improved the leaf area index by 23.4%, plant height by 1.8%, aboveground dry matter accumulation by 15.9%, water use efficiency by 3.8%, nitrogen use efficiency and 34.2%, and grain yield by 10.0–11.0%. Dense planting also increased the maize ear number per area by 34.3% but decreased grain number per ear by 12.5%, 1000-grain weight by 7.2%, and harvest index by 2.4%. Notably, the density increase range emerged as the primary factor influencing yield and its components, with changes in grain number per ear the most significant contributor to yield variations. A 25–50% density increase range was identified as optimal, resulting in an 11.5–13.4% yield increase. Average local planting densities were 63,496 plants·ha^–1 in the Northwest, 58,928 plants·ha^–1 in the Huang-Huai-Hai region, 58,234 plants·ha^–1 in the Northeast, and 51,761 plants·ha^–1 in the Southwest. Here, we show for the first time that the optimal density increase range varied by region: 25–50% for the Northeast, >50% for the Huang-Huai-Hai and Southwest, and 0–25% for the Northwest. These findings highlight the importance of tailoring planting density to local conditions, offering a scientific basis for optimizing maize production across diverse regions in China.

Zhang, M., Zhao, X., Han, X. et al. Optimizing planting density for enhanced maize yield and resource use efficiency in China. A meta-analysis. Agron. Sustain. Dev. 45, 29 (2025). https://doi.org/10.1007/s13593-025-01027-0

To solve soil fertility problems, most smallholder farmers in sub-Saharan Africa use fallow periods. However, population growth along with land shortage tends to shorten the duration of fallows, resulting in a steady decline in soil fertility. Although nitrogen (N) plays a key role in soil fertility, current methods for maintaining N supply in cropping systems are inadequate, especially in N poor soils. Addressing this issue is crucial for improving agricultural productivity and reducing environmental impact. The objective of this study was to explore innovative ways to maintain N supply in N poor soils by identifying the appropriate levers and practices. We designed a general model describing N cycle in a cropping system in a humid savanna in Ivory Coast. We examined the impact of different processes involved in N cycle, including mineralization, nitrification, and fallow characteristics on the yield of a crop such as corn. Our study innovatively assesses the benefits of incorporating nitrification inhibition into traditional African cropping systems and provides a modelling tool to assess its impact. The model confirms that in low input agricultural systems, soil fertility is maintained by the increase in soil organic matter during fallow and its subsequent mineralization. We showed that variation in nitrification during the cropping cycle (fallow-crop) does not have a significant effect on corn yield. However, with the addition of N fertilizers, nitrification inhibition significantly increases crop yield. Indeed, nitrification inhibition increases the efficiency of fertilizer use, which reduces losses of N fertilizer. Furthermore, legume-based fallow is able to increase corn productivity much more than a nitrification-inhibiting fallow regardless of the length of fallow periods. Finally, the models suggest that using nitrification-inhibiting grasses as cover crops for corn would be beneficial if mineral N fertilizer is used.

Ouattara, W.A., Konaré, S., Tondoh, E.J. et al. Modelling the impact of nitrification inhibition in a fallow-based West African corn cropping system. Agron. Sustain. Dev. 45, 28 (2025). https://doi.org/10.1007/s13593-025-01026-1

Nitrification and nitrogen (N) immobilization are important pathways in soil N transformations, involving soil N loss and retention, respectively. The ratio of nitrification to N immobilization generally reflects the potential risk of soil N loss. However, little is known about the response of this ratio to anthropogenic carbon (C) and N inputs, but also climate and soil conditions. Here, we aimed to elucidate, for the first time, the impacts of chemical fertilizer and manure application on the ratio of gross nitrification to N immobilization by using ¹⁵N dilution technology, based on ten long-term fertilization trials spanning multiple climatic zones in eastern China. Results showed that manure application differentially increased gross N immobilization rather than nitrification compared to the chemical fertilizer treatment, leading to manure-induced decreases in gross nitrification to N immobilization ratio ranging from 1.2 to 93% across the sites. The decreased gross nitrification to N immobilization ratio in the manure treatment was mainly due to the increased ratio of bacteria to nitrifiers abundance. Manuring was more effective for a decrease in the gross nitrification to N immobilization ratio at sites characterized by high rainfall and low soil pH, as it prevented soil pH decline thereby favoring bacterial abundance and N immobilization. Consequently, manure application resulted in a substantial increase in soil total N accumulation, facilitated by increased microbial N immobilization that promoted microbial biomass. These findings suggest that substituting manure for chemical fertilizer in the areas with high rainfall and acidic soils promisingly reduces soil N loss risk, with positive consequences for soil N retention. This knowledge highlights the potential to reconcile soil N loss and fertility improvement through optimizing regional manure management, which offers valuable insights for the development of a tailored regional fertilization management strategy.

Wang, J., Zhang, L., Liu, K. et al. Minimizing the potential risk of soil nitrogen loss through optimal fertilization practices in intensive agroecosystems. Agron. Sustain. Dev. 45, 9 (2025). https://doi.org/10.1007/s13593-025-01006-5

On-farm research with farmer participation is promoted as a transformative approach that increases inclusivity and innovation within agricultural research, ultimately improving research quality and outcomes. However, little is known about the farmers who participate in on-farm research (i.e., research farmers) or how well these farmers represent the broader agricultural community, including farmers not involved in research (i.e., non-research farmers). This gap in knowledge raises questions about both the application and generalizability of on-farm research findings as well as the equitable distribution of on-farm research benefits among farmers. In this study, we examine how research farmers’ behavior and perceptions differ from non-research farmers using two online surveys among US row crop farmers, focused on cover crops (N = 211). We find that among farmers that have engaged in cover cropping, research and non-research farmers are demographically nearly identical; however, there are several significant differences between the two farmer groups’ perceptions, social networks, and on-farm management. Here, we show for the first time that research farmers perceive cover cropping practices as less challenging and are more willing to engage in innovative cover crop practices compared to non-research farmers. Research farmers also exchange farming information with more people and are more willing to share their farm data, compared to non-research farmers. Given these findings, we consider the practical and epistemological consequences of extending insights gained from working with research farmers to the broader agricultural population. Our results highlight potential implications for farmer communication and engagement strategies, especially among those farmers who are not typically involved with on-farm research activities.

Our study aims to determine the yield potential and yield gap and to identify key factors associated with yield losses in irrigated rice fields in Argentina. Our findings indicated that 22% of the current yield gap is due to the sowing date, 9% is associated with the adoption of rotation/succession, and 5% is associated with the early onset of irrigation up to the V3 stage. The implementation of these practices has demonstrated the potential to reduce the current yield gap from 48% to 33%.

Meus, L.D., Quintero, C.E., da Silva, M.R. et al. Irrigated rice yield plateaus are caused by management factors in Argentina. Agron. Sustain. Dev. 44, 56 (2024). https://doi.org/10.1007/s13593-024-00989-x