稻麦两熟制下秸秆还田模式的产量和经济效益分析

Analysis of Yield and Economic Benefit of Straw Incorporation under Rice-Wheat Double Cropping System

明确不同秸秆还田模式对小麦、水稻产量和经济效益的影响,对推广秸秆还田具有重要意义。利用稻麦复种长期田间定位试验2012-2018年的数据,分析了秸秆不还田(S0)、麦秸还田(WS)、稻秸还田(RS)和稻麦秸均还田(WRS)4种秸秆还田模式对作物产量、氮肥利用率、秸秆增产率、秸秆边际产量和秸秆农学利用率的影响。结果表明:秸秆还田均增加水稻产量,其中RS和WRS模式增产效果均显著大于WS模式;小麦产量随秸秆还田年限呈"减产-稳产-增产"的变化趋势。秸秆的周年增产率和农学利用率分别为5.65%~13.60%和0.11~0.17kg/kg。与RS模式相比,WRS模式属于秸秆过量还田,其秸秆增产效率降低。秸秆还田提高稻麦氮肥周年利用率1.67~4.01kg/kg,其中RS和WRS模式较WS模式更利于作物的氮吸收。WS、RS和WRS模式的稻田周年净收益较不还田模式分别增加1690、4875和4177元/(hm^2·年),其中RS和WRS模式均显著高于WS模式。综合以上结果,麦季稻秸还田模式(RS)既可提高还田秸秆利用率,又可增加稻田净收益,推荐在稻麦两熟农田采用。

Exploration of the effects of straw incorporation mode on yield benefits of wheat and rice has great significance for popularizing straw incorporation. In this work, we conducted a long-term field experiment from 2012 to 2018 to study the effects of straw incorporation modes on crop yield, agronomic nitrogen use efficiency, and the rate of yield increase, marginal yield and agronomic use efficiency of straw returned. The experiment included four straw incorporation modes: no straw incorporation(S0), wheat straw incorporation(WS), rice straw incorporation(RS) and both rice and wheat straw incorporation(WRS). The results showed that: rice yield was increased under different straw incorporation modes, of which the output of the RS and WRS modes were significantly higher than that of the WS mode, while wheat yield showed a trend of "decrease–stabilization–increase" with the times of straw incorporation.The annual yield increase rate and agronomic use efficiency of straw were 5.65%-13.60% and 0.11-0.17 kg/kg, respectively. Compared with the RS mode, the amount of straw returned of the WRS mode was excessive, and the straw utilization rate was decreased. Straw incorporation improved the annual nitrogen use efficiency by about 1.67-4.01 kg/kg, and the RS and WRS modes were more conducive to crop utilization of nitrogen than the WS mode. Compared with the S0 mode, the annual net incomes of WS, RS and WRS modes increased by 1 690, 4 875, and 4 177 yuan/(ha·a) respectively. Among of the three straw incorporation modes, the annual net benefits of the RS and WRS modes were significantly higher than that of the WS mode. In conclusion, the rice straw incorporation mode(RS) was recommended to adopt in rice-wheat double cropping system, which can improve the straw utilization efficiency and increase the paddy field’s net benefit.