不同有机物料还田对农田土壤有机碳以及微生物量碳的影响

为促进农业有机废弃物料的循环利用,选用来自5个涉农系统的有机物料(酒渣、沼渣、菌渣、猪粪和农田秸秆)进行还田,以单施化肥为对照研究其对土壤有机碳(Soil organic carbon,SOC)、微生物量碳(Microbial carbon,MBC)以及微生物商(Microbial quotient,Qmb)的影响。2011—2013年的数据结果表明:1)与无机肥对照相比,有机物料还田显著促进土壤SOC的积累,3年平均提高43%;其中沼渣和菌渣的效果好于猪粪、酒渣与秸秆,农田系统外的有机物料优于秸秆,更有利于SOC的积累。2)有机物料促进MBC的增加,较对照平均增加34%,其中酒渣、秸秆和猪粪对MBC的影响大于沼渣与菌渣。3)5种物料中,酒渣和秸秆还田提高土壤Qmb值;沼渣和菌渣还田降低土壤Qmb值,提高SOC的稳定性。

Effects of agricultural organic wastes incorporation on soil organic carbon and microbial carbon

In order to make recycling use of agricultural organic wastes,five kinds of agricultural organic wastes were incorporated to the wheat-maize rotation system,including wine residue (WR),biogas residue (BR),mushroom residue (MR),pig manure (PM) and crop straw (CS),with a mineral fertilizer (CF) as control.Soil organic carbon (SOC) and microbial carbon (MBC) were measured.The results from 2011 to 2013 showed that: 1) SOC was significantly improved by incorporation of organic wastes,with an average increment of 43% in comparison with CF.Among the five organic wastes,BR and MR showed better effects on the improvement of SOC than those of PM,WR and CS;and the organic wastes from off-farm system were more conductive to C sequestration. 2) MBC content was promoted by incorporation of organic wastes and was increased by 34% on average when compared to CF.The impacts of WR,CS and PM on MBC were greater than those of BR and MR. 3) The microbial quotient was increased by the incorporation of wine residue and crop straw in the five organic wastes,whereas decreased by biogas residue and mushroom residue.The stability of SOC was increased by the incorporation of biogas residue and mushroom residue.