Response of wheat and maize yields to different tillage practices across China: A meta-analysis

Abstract

Tillage practice can change soil properties, regulate crop root development and nutrient availability, thus affecting crop growth and yield. However, the effect of no tillage (NT) and deep tillage (DT) on crop yield relative to conventional tillage (CT) under varied environmental and management conditions is unclear in China. We assessed the yield response of wheat and maize to NT and DT relative to CT based on collected field data (518 observations) with a meta-analysis. In general, NT led to negative yield response of both crops relative to CT, whereas maize presented a positive yield response (6.0 %) to NT in sandy soil, and crop yield responses to NT were not significantly different among environmental and management factors. DT significantly increased the yield of wheat (8.7 %) and maize (8.2 %) over CT. For wheat, the yield response to DT was similar across soil textures, climate conditions, experiment durations, N fertilizer rates, and residue managements; however, the interval DT every 2–3 years (13.2 %) and monoculture (13.9 %) increased yield response than the continuous DT (8.4 %) and double cropping system (8.9 %), respectively. The yield response of maize to DT was greater in semidry region (16.1 %) and under high N fertilizer rate (>300 kg N ha−1) (16.1 %), interval DT (12.4 %) compared with those in humid (7.5 %) and semi-humid (6.8 %) regions, low N fertilizer rates (<300 kg N ha−1) (6.9 %−7.5 %), and continuous DT (7.8 %), respectively; but other environmental and management factors did not affect its yield response. Overall, NT presented similar yield of wheat and maize to CT, while DT significantly enhanced their yields; this analysis revealed the crucial environmental and management factors influencing yield response to tillage practices in China, we also gave some suggestions on selecting appropriate tillage methods to realize high crop yield or/and agricultural sustainable development.