Returning crop straw to farmland is widely used to replenish organic matter, recycle nutrients, and improve soil conditions. Research also shows that soil microorganisms influence plant growth and disease, making them important partners in sustainable agriculture. However, crop residues can carry pathogens, and their effects depend on how they are managed. Most previous studies have emphasized soil fertility and crop yield or compared broad tillage systems. Less is known about how specific straw burial depths alter microorganisms around and inside maize roots, or how those changes relate to ear rot and the accumulation of harmful fungal toxins in grain.
A study (DOI: 10.48130/aee-0026-0019) published in Agricultural Ecology and Environment on 18 August 2026 by Yanpo Yao's team, Ministry of Agriculture and Rural Affairs, found that deeper straw return improved soil conditions and shifted microbial communities toward potentially protective groups, alongside lower disease incidence and toxin contamination.
Working in Gongzhuling, Jilin Province, the researchers compared four straw incorporation depths: 0–5, 10–20, 20–30, and 30–40 centimeters. Each treatment had three replicate plots, and the experiment included two maize varieties, Fumin 985 and Xianyu 335, with contrasting disease susceptibility. Investigators assessed ear rot incidence and severity, measured deoxynivalenol and zearalenone in kernels using liquid chromatography and mass spectrometry, and examined soil physical, chemical, and microbial properties. DNA sequencing characterized bacterial and fungal communities in bulk soil, soil surrounding roots, and internal root tissues. Quantitative PCR independently measured the abundance of Fusarium and Aspergillus, while network analysis and structural equation modeling explored relationships among soil conditions, microorganisms, and crop health. The measurements revealed substantial changes under deeper incorporation. At 30–40 centimeters, total soil pore area increased by 162.5%, organic carbon by 22.5%, and available phosphorus by 152.1% relative to shallow return. The soil quality index was approximately four times higher, although bulk density also rose modestly. Microbial indicators contributed more than 35% of the index under the deepest treatment. Sequencing showed enrichment of groups containing beneficial microorganisms, including Trichoderma and Enterobacteriaceae, under deeper treatments. PCR confirmed lower absolute abundances of Fusarium and Aspergillus around roots and within root tissues. Microbial networks also showed altered organization and more positive associations, consistent with a potentially more resilient community. These changes accompanied reductions of 20.0%–50.0% in the ear rot disease index under the two deepest treatments. The deepest treatment kept both measured toxins below the food safety thresholds used in the study. Importantly, some visually healthy kernels contained elevated toxin levels, showing that appearance alone cannot establish grain safety. Statistical modeling supported an indirect pathway linking incorporation depth to improved soil conditions, microbial shifts, and reduced disease and contamination, although the proposed biological mechanisms require further experimental testing to establish specific causal microbial roles.
Overall, the research connects residue management with soil ecology and grain safety. The authors propose 20–30 centimeters as a useful balance between disease control and the likely additional energy demands of deeper tillage, rather than a proven economic optimum. Further work should test performance across environments, quantify costs, and sample deeper soil layers to clarify how buried straw influences the wider root zone.
###
References
DOI
10.48130/aee-0026-0019
Original Source URL
https://doi.org/10.48130/aee-0026-0019
Funding information
This work was financially supported by the China Postdoctoral Science Foundation (Grant No. 2025M773816), the Postdoctoral Fellowship Program (Grade C) of the China Postdoctoral Science Foundation (Grant No. GZC20251849), the National Agricultural Product Quality and Safety Risk Assessment Project (Grant No. 20254019), the Innovation Program of the Chinese Academy of Agricultural Sciences (Grant Nos ZHJGCGX202507; CAAS-ZDRW202416), and the Project of Science and Technology Program of Inner Mongolia Autonomous Region (Grant No. 2025YFHH0180).
About Agricultural Ecology and Environment
Agricultural Ecology and Environment (e-ISSN 3070-0639) is a multidisciplinary platform for communicating advances in fundamental and applied research on the agroecological environment, focusing on the interactions between agroecosystems and the environment. It is dedicated to advancing the understanding of the complex interactions between agricultural practices and ecological systems. The journal aims to provide a comprehensive and cutting-edge forum for researchers, practitioners, policymakers, and stakeholders from diverse fields such as agronomy, ecology, environmental science, soil science, and sustainable development.