寒区长期秸秆全量还田对水稻土理化特性的影响

Effects of long-term all rice straw returning on soil physio-chemical properties in cold region

现今东北地区水稻种植面积得到显著增加,其总种植面积是改革开放初期的6倍。随着水稻种植面积的增加,秸秆还田在黑龙江省农垦已经成为一项常规的农业栽培措施。为研究寒区水稻秸秆全量还田与秸秆腐熟剂相结合施用对水稻土生产力的影响,在黑龙江省八五〇农场开展了7年的大田定位试验。在施用秸秆腐熟剂的基础上进行水稻秸秆粉碎全量还田处理,以不还田处理作对照,测定秸秆还田处理对土壤容重、有机质、有效磷、缓效钾、速效钾、pH、阳离子交换量(CEC)和水稻产量的影响。结果表明,秸秆还田后水稻平均产量显著高于对照460kg·hm^-2。还田处理7年后,土壤有机质含量及pH没有变化;土壤容重显著降低,由1.32g·cm^-3降低到1.25g·cm^-3,降低了0.07g·cm^-3。与实施初期相比,还田处理的有效磷、缓效钾、速效钾含量和CEC值分别增加了11.2%、14.3%、42.3%和7.0%;与对照相比,有效磷、缓效钾、速效钾含量和CEC值分别显著增加了10.4%、14.1%、45.0%和6.3%。东北地区水稻长期全量秸秆还田可以提高水稻产量,改善土壤的理化性状,且秸秆还田年限越长,土壤的理化性状提高越明显。

Currently,the rice planting area in Northeast China is significantly increasing,which are 6 times the area of the early era of reform and opening-up.Rice straw returning to soil is a routine agricultural practice in Heilongjiang Land Reclamation Bureau,which can enhance the straw resource utilization and reduce environmental pollution.Here,we conducted a seven-year field experiment with combined application of straw-decomposing inoculants and returning straw in Heilongjiang 850 Farm,their effects on soil physical and chemical properties and rice yields were investigated.The field without returning straw used as a control(CK).Then,we analyzed the contents and changes of soil bulk densities,organic matter,available phosphorus,slowly-available and readily available potassium,pH and CEC(Cation Exchange Capacity)values and the rice yield.The results showed that the average rice yield with straw returning was significantly higher than that with CK.After 7 years,the contents of soil organic matter and pH with straw returning treatment did not significantly change;soil bulk density significantly decreased by 0.07 g·cm^-3 compared to CK;the contents of soil available phosphorus,slowly-available and readily available potassium,and CEC values significantly increased by 11.2%,14.3%,42.3%and 7.0%,respectively.Compared with CK,the contents of soil available phosphorus,slowly-available and readily available potassium,and CEC values with straw returning treatment significantly increased by 10.4%,14.1%,45.0%and 6.3%,respectively.In conclusion,long-term rice straw returning with straw-decomposing inoculants could improve soil physical and chemical properties and increase the rice yield,and the trend would be increasing with straw return times.