秸秆还田与化肥减量配施对稻茬麦土壤养分、酶活性及产量影响

摘要

[Objective] Rice-wheat rotation each year is one of the most important agricultural planting systems in Hanzhong plain region.The field experiments in winter wheat growth period under rice-wheat rotation system were conducted to investigate the effects of reduction of N,P,and K fertilization rates plus rice straw return on soil nutrient,enzyme activities and wheat yield.[Method] The experiment design included four treatments:NPK fertilization without straw return,NPK fertilization with straw return (NPKS),NPK fertilization rate reduction by 15 ％ plus straw return (-15 ％ NPKS) and NPK fertilization rates reduction by 30 ％ plus straw return (-30 ％ ％ NPKS).[Result]Compared to NPK (CK),NPKS,-15 ％ NPKS and-30 ％ NPKS treatments all reduced the soil bulk density of 0-15 cm soil layer,especially in 0-5 cm soil layer.Compared to NPK,NPKS and-15 ％ NPKS treatments increased LOC and TOC contents in 0-15 cm soil layer,however,-30 ％ NPKS treatment reduced LOC and TOC contents,straw return treatments increased TOC content in 15-30 cm soil layer.The NPKS and-15 ％ NPKS treatments increased the urease activities by 32.7 ％ and 29 ％,respectively;The NPKS treatment increased the invertase activity by 19.8 ％,however,-15 ％ NPKS and-30 ％ NPKS treatments significantly reduced the invertase activities by 32.5 ％ and 10.7 ％,respectively,meanwhile,both-15 ％ NPKS and-30 ％ NPKS treatment reduced soil nutrient contents.As far as wheat yield,the-15 ％ NPKS treatment had no significant effect on wheat yield,but the-30 ％ NPKS treatment did reduce wheat yield.Correlation analysis showed that the wheat yield was significantly correlated with soil organic carbon.The appropriate reduction in NPK fertilizer application rate (-15 ％) plus straw return had no significantly negative effects on soil fertility and crop yield.[Conclusion] In conclusion,under rice-wheat rotation system,the appropriate reduction in NPK fertilizer application plus rice straw return had positive effects on agriculture,economy and environment,which could not only ensure the crop yield and improve the utilization of straw but also reduce fertilizer inputs and environmental pollution.%[目的]稻麦一年二熟轮作是汉中盆地小麦生产的最重要种植制度之一,本文采用田间试验,研究水稻秸秆全量还田对小麦季土壤养分、酶活性及小麦产量的影响,旨在揭示本地区水稻秸秆还田替代部分化肥的产量及沃土效应.[方法]试验共设置氮磷钾配施(NPK)、氮磷钾+秸秆还田(NpKS)、氮磷钾减量15％+秸秆还田(-15 ％NPKS)、氮磷钾减量30％+秸秆还田(-30％ NPKS)4个处理.[结果]与秸秆不还田(NPK)相比,水稻秸秆还田处理(NPKS、-15％NPKS和-30％NPKS)均不同程度降低了0～15 cm土层的土壤容重,其中对0～5 cm土层影响最为显著;NPKS和适量化肥减量(-15％ NPKS)提高了0～15cm土壤有机碳(TOC)和活性有机碳(LOC)含量,而高量化肥减量(-30％ NPKS)会降低TOC和LOC含量,还田处理均提高了15～30 cm土层有机碳(TOC)含量;秸秆还田(NPKS)及适量化肥减量(-15 ％NPKS)增加了土壤脲酶活性,增幅分别达32.7％和29.0％;NPKS处理提高了蔗糖酶活性,增幅达19.8％,而化肥减量(-15％NPKS和-30％ NPKS)显著降低了蔗糖酶活性,降幅分别为32.5％和10.7％.与秸秆不还田(NPK)相比,秸秆还田与化肥减量配施均降低了土壤养分含量.此外,适量化肥减量(-15％NPKS)对小麦产量无显著影响,而高量化肥减量(-30％ NPKS)会显著降低小麦产量.相关分析表明,小麦产量与土壤有机质及养分含量显著相关.秸秆还田与化肥氮磷钾减量15％配施对小麦产量和土壤肥力无负面影响.[结论]因此,稻麦轮作体系下,水稻秸秆全量还田同时氮磷钾肥减量15％措施不仅能够保证小麦季小麦稳产,而且减少环境污染风险,具有农学、经济、环境三赢潜力.