Work

Partial substitution of chemical fertilizer with organic amendments reduces yield variability by shifting climate to soil-microbe-mediated regulation under equivalent nutrient supply

Year: 2026

Type: article

Abstract: Intensive agriculture confronts critical challenges of soil nutrient depletion and yield instability under escalating climate variability. To evaluate whether organic material amendments stabilize soil nutrients and enhance agricultural resilience, a five-year field trial (2018–2023) was conducted to compare chemical fertilizer (NPK), chemical fertilizer plus crop straw (NPK+S), and chemical fertilizer plus organic manure (NPK+O) in a wheat–maize rotation on the North China Plain. We monitored inter-annual dynamics of climate, soil nutrients, bacterial communities, and yields, and analyzed environmental-yield linkages via multivariate analyses including partial least squares path modeling. (PLS-PM). The results showed that organic amendments significantly increased soil organic carbon 4.1%–7.7% and total nitrogen 3.9%–6.2%, reduced their inter-annual coefficient of variation (CV) by 12.9%–32.4%, and concurrently lowered crop yield CV by 17.2%–27.7%. Straw return (NPK+S) delayed nutrient mineralization, attenuated precipitation-induced nutrient depletion, and provided synergistic water conservation and nutrient stabilization benefits during droughts. Conversely, whereas NPK + O increased leaching losses under intense rainfall. Phylum-level analysis revealed divergent microbial pathways: straw enriched oligotrophic Acidobacteriota and polysaccharide-degrading Bacteroidota for carbon stabilization, whereas manure triggered an excessive Actinobacteriota bloom while suppressing Proteobacteria , indicating stress-oriented filtering that may weaken functional resilience. PLS-PM demonstrated that the bacterial community mediated the effects of soil nutrients on yield, with the pathway shifting from direct climate-to-yield dominance under NPK to indirect soil-biology-mediated regulation under organic amendments. These findings indicate that straw return is optimal for semi-arid regions with high precipitation volatility to bolster system resilience, while manure supplementation requires strategic irrigation to mitigate nutrient leaching—providing key pathways for climate-smart agriculture.

Source: European Journal of Agronomy

DOI: 10.1016/j.eja.2026.128287