Soil properties affect crop yield changes under conservation agriculture: a systematic analysis
Xiaohua Ren, Wenjing Zou, Juying Jiao, Ryan Stewart, Jinshi Jian- Soil Science
Abstract
Conservation agriculture (CA) has the potential to sustain soil productivity and benefit agroecosystems, yet it is not fully understood how yield responses of different cropping systems are affected by inherent soil characteristics, e.g., texture and dynamic soil properties, such as aggregation, nutrients, and erosion. In this study, we conducted a systematic review to compare crop yield from cropland with conventional management versus different CA practices, specifically reduced‐ or no‐tillage, agroforestry, organic farming, and cover crops. The data were first analyzed for different climatic regions, soil textures, and cash crop types. We then quantified how yield responses correlated with soil properties changes under different CA practices. The results showed that CA practices were associated with an overall mean crop yield increase of 12%. This response was primarily driven by corn, which had a mean yield increase of almost 41% after CA implementation, whereas other cash crops did not have significant yield responses or showed slight decreases, as rotation with mixtures of multiple cash crops had mean decrease of 6% when using CA. The increase in corn yield after CA may be related to the enhanced ability of that crop to absorb nutrient elements (e.g., nitrogen) and reduce nutrient leaching. Agroforestry increased crop yield by 66% and cover cropping increased yield by 11%, likely due to increases in soil water content and nutrient availability and decreases in erosion and surface runoff. However, other agricultural systems showed no significant increase after CA compared to conventional row cropping practices. Using CA practices had the greatest yield benefit in tropical climates and when farming in coarse‐textured soils. In addition, legumes and grass‐legume mixtures resulted in significant cash crop yield increases, possibly because legumes promoted the increase of soil nitrogen and depleted soil moisture less compared with other cover crops. The results provide new insight into how interactions between soil properties and CA practices affect crop yield, and at the same time can help guide the development of practical, evidence‐based guidelines for using conservation practices to improve yield in corn and other cash crops.
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