河西绿洲灌区玉米秸秆带膜还田腐解特征研究

为探讨河西绿洲灌区玉米秸秆带膜还田时的腐解规律,采用尼龙网袋法,对不同带膜还田模式下玉米秸秆的腐解特征进行研究,旨为当地玉米秸秆还田提供理论依据和技术指导。结果表明：土壤温度是影响当地玉米秸秆腐解的主要因素,经过180 d腐解后,各还田处理秸秆的腐解率均在50%以上,其中翻压处理的腐解率（67.5%～76.0%）高于覆盖处理（50.5%～59.0%）,而且腐解主要发生在还田后的30～120 d。秸秆在还田前期（前60 d）会与作物争夺土壤氮素,但是在还田后期会释放一定氮素,而且翻压和粉碎还田释放的氮素要高于覆盖和整株还田。从秸秆完全腐解的预测时间看,整株半量翻压、整株半量覆盖、粉碎半量翻压、粉碎全量翻压、粉碎半量覆盖和粉碎全量覆盖处理分别需要247、326、212、227、277和299 d才能完全腐解,可见,在河西绿洲灌区实行带膜还田前景广阔,而且翻压优于覆盖,粉碎优于整株,半量优于全量。

Decomposition characteristics of corn straw return to planting row above cover plastic film in Hexi Oasis Irrigation

This study intends to investigate decomposition changes of corn straw return to planting row above cover plastic film in Hexi Oasis Irrigation,Nylon net bags was used to study decomposition characteristics of corn straw under different return to planting row above cover plastic film methods,and aims to provide a theoretical basis and technical guidance for local corn straw return to field.The results showed that,soil temperature was the main influencing factor of local corn straw decomposition.After 180 days decomposition,all treatments the decomposition rate were more than 50%,the decomposition rate of straw-buried treatments（67.5%-76.0%） higher than straw-mulched treatments（50.5%-59.0%）,and decomposition mainly occurred in straw return to field after 30 to 120 days.Before 60 days straw return to field stage,straw and crop competition for soil nitrogen,straw would release some nitrogen in the later date,straw-buried and straw-crushed return to field the content of nitrogen releasing were higher than straw-mulched and whole plant return to field,respectively.from straw completely decomposition prediction time,the half amount of whole plant straw-buried,the half amount of whole plant straw-mulched,the half amount of straw-crushed and straw-buried,the total of straw-crushed and straw-buried,the half amount of straw-crushed and straw-mulched,the total of straw-crushed and straw-mulched were completely decomposed to 247,326,212,227,277 and 299 d,respectively.To implement corn straw return to planting row above cover plastic film have broad prospects in the Hexi Oasis Irrigation,and straw-buried better than straw-mulched,straw-crushed better than the whole plant,the half amount straw return to field better than the total.