关键词: 秸秆还田, 全国, 农作物, 产量效应, 整合分析

Abstract:

【Objective】In order to provide scientific grounds for the implementation of grain crop straw return, this study quantified the yield effect of straw return.【Method】It was collected and sorted out the published Chinese literatures in the past 30 years (a total of 274 piece of literature and 1 930 pairs data until December 31, 2019). By using meta-analysis method, the comprehensive effect of straw returning on crop yield was clarified with the main analysis process, included calculation of effect value, heterogeneity test, meta-subgroup analysis and publication bias test. And then, the effects under different experiment region, average annual temperature, average annual precipitation, soil texture, soil pH, crop type, planting system, tillage method, fertilization method, experiment duration and return amount was further quantitatively analyzed.【Result】Compared with straw remove, straw return significantly increased crop yield, and the average increasing rate was about 8.06%, with a 95% confidence interval of 7.52%-8.60%. No publication bias was found in the result. The yield effect was the highest in the southeastern region, reaching 9.37% (95% CI: 8.11%-10.64%). The straw-return effect was higher when the average annual temperature was 5-10 °C and the average annual precipitation is more than 1 200 mm. In different soil texture, the yield effect of straw return was 8.13% in clay (95% CI: 6.80%-9.49%), 9.04% in loam (95% CI: 8.06%-10.01%) and 6.96% in sandy soils (95% CI: 5.18%-8.77%), respectively. Among the three types of grain crops, namely, wheat, corn, and rice, the increase rate of yield on maize reached 9.22% (95% CI: 8.38%-10.05%) by straw returning. Plowing and no-till was the best tillage methods exerting the yield effect of straw returning, the increasing rate of yield were 11.05% (95% CI: 10.05%-12.05%) and 8.98% (95% CI: 7.21%-10.79%), respectively. When the straw was returned to the field without fertilization, the crop yield was significantly increased with an increase rate of 25.66% (95% CI: 22.04%-29.38%), which was significantly higher than that of 8.08% (95% CI: 7.50%-8.68%) under normal fertilization, but the overall yield level was lower. The yield increase rate of straw mulching reached 9.56% and the yield increase effect of straw mulching over 20 years was significantly increased (yield increase rate: 15.42%, 95% CI: 11.05%-19.95%). In addition, the most suitable amount of straw was half of the ex-crop (increase rate of yield was 9.09%, 95% CI: 7.41%-10.79%).【Conclusion】Straw return could significantly increase crop yield in different agricultural production areas. Furthermore, the long-term implication of crop straw with no-till or plowing tillage, normal fertilization and appropriate amount, could maintain continuous increase in crop yield.

Key words: straw return, China, crop, yield effect, meta-analysis