麦稻两熟地区不同埋深对还田秸秆腐解进程的影响  

Effect of embedding depth on decomposition course of crop residues in rice-wheat system

作　　者：刘世平[1] 陈文林[1] 聂新涛[1] 张洪程[1] 戴其根[1] 霍中洋[1] 许轲[1] 

机构地区：[1]扬州大学江苏省作物栽培生理重点实验室,江苏扬州225009

出　　处：《植物营养与肥料学报》2007年第6期1049-1053,共5页Journal of Plant Nutrition and Fertilizers

基　　金：国家农业科技成果转化基金(02EFN3200230);科技部重点攻关项目(2004BA520A03)资助

摘　　要：为探讨稻麦两熟地区还田秸秆的腐解进程,用尼龙网袋法研究了麦稻秸秆不同埋深(0、7、14 cm)对还田秸秆腐解及C/N比的影响。结果表明,在麦田,埋深14 cm的秸秆腐解速度最快,覆盖在表层较慢。稻田由于有水层的作用和高温高湿的环境,秸秆腐解比麦田快,覆盖在表层比埋入土中的略慢。麦季稻秸覆盖还田一季后秸秆残留率在60%左右,埋入土中的残留率在40%左右;稻季麦秸覆盖还田一季后秸秆残留率在25%左右,而埋在土中的残留率在20%左右。随着还田秸秆的腐解,秸秆含氮量逐渐增加,全碳含量下降,秸秆C/N比降低。麦季稻秸覆盖C/N比较高,而稻季麦秸覆盖的C/N比较低。一季后麦田稻秸的C/N比平均在30左右,稻田麦秸在15以上,比土壤腐殖质的C/N比高,说明种植一季作物后,还田的秸秆尚未完成腐殖化过程。Wheat and rice straw were enclosed in nylon nets and returned to rice and wheat field, respectively, to study the effect of embedding depth （0, 7, 14 cm） on decomposition course and C/N ratio of crop residues in wheat-rice rotation system. The results showed that rice straw embeded into soil layer of wheat field decomposed faster than surface mulching, and rice straw had the highest decomposition rate at embedding depth of 14 cm. Wheat straw embedded in rice field decomposed faster than rice straw in wheat field, due to the existence of water layer, higher moisture and temperature in rice field, but mulched wheat straw decomposed slower than that of being embedded. After decomposition for one crop season, the residual rates for mulched and embedded rice straw were 60 % and 40 %, respectively, while the resid- ual rates for mulched and embedded wheat straw were 25 % and 20 %, respectively. During the course of decomposition, C/N ratio decreased due to the loss of total C. The C/N ratio of rice straw in surface layer of wheat field remained high, while that of wheat straw was the lowest in surface layer and was the highest in mid-layer of rice field. The C/N ratio of rice and wheat straw after one crop season was about 30 and 15, respectively, higher than that of humus, indicating that the humification process was not accomplished.

关 键 词：稻麦两熟 秸秆还田 腐解 C/N比 

分 类 号：S141.4[农业科学—肥料学]