有机物料还田对华北小麦玉米两熟农田土壤有机碳及其组分的影响

中国农业废弃物种类多、数量大、利用率低、污染重。将有机物料还田,是实现废弃物资源化利用的重要途径。该研究以循环农业理念为指导,选择代表农田内循环的秸秆以及代表农沼循环、农牧循环、农菌循环、农工循环的废弃物沼渣、猪粪、菌渣和酒渣为试验材料,开展了等碳量还田定位试验,分析各有机物料还田后对土壤有机碳及其组分的影响。结果表明:1)连续施用有机物料提高了土壤总有机碳(TOC)、易氧化有机碳(LOC)、微生物量碳(MBC)和可溶性有机碳(DOC)含量。随着有机物料还田年限的增加,土壤TOC、LOC和MBC含量均不同程度地增加,年平均增幅分别为:15.57%~22.82%、20.00%~38.31%和16.30%~50.56%。还田5年后各有机物料处理土壤TOC、LOC、MBC和DOC含量平均分别是无机肥处理的1.24~1.62、2.07~3.19、1.20~2.06和1.05~3.36倍。2)不同有机物料中均利于土壤TOC含量的提高,秸秆提升效果相对最差,沼渣、菌渣、猪粪、酒渣和秸秆还田处理的0~20cm土壤TOC含量平均增长速率分别为:22.82%、21.88%、16.42%、16.13%和15.57%。

Effects of different organic wastes incorporation on soil organic carbon and its fraction under wheat-maize cropping system in North China Plain

Abstract: There are large amounts of agricultural waste produced in China annually and China has become the world''s largest agricultural waste generator with the rapid development of farming, breeding, and the agricultural processing industry. The vastmajority of these wastes are under utilized as a potential resource, which not only causes a huge waste of resources but also creates serious environmental pollution. Thus,acircular agriculture pattern of planting and animal farming and/or agro-processing industry which is good for reducing pollution, improving the use of natural resources and saving fossil energy are important to promote sustainable development of agriculture and the environment. Based on the conception of circular agriculture, five types of organic wastes were applied to the field at an equal rate of carbon in the study including crop straw (CS), biogas residue (BR), pig manure (PM), mushroom residue (MR) and wine residue (WR). The effect of different organic waste on soil total organic carbon and labile organic carbon fractions were investigated and analyzed in this paper. The field experiment was established from June 2010 in a wheat-maize rotation cropping system. The data analyzed in this paper were observed from 2010 to 2014. The main results showed that: (1)Soil total organic carbon (TOC), labile organic carbon (LOC), microbial biomass carbon (MBC) and dissolved organic carbon (DOC) were all increased graduallyunder different organic wastes amendments. Soil TOC, LOC, MBC and DOC content were 1.24-1.62, 2.07-3.19, 1.20-2.06 and 1.05-3.36 times of inorganic fertilizer treatment after applying organic material 5 years.The annual increase rate of soil TOC, LOC and MBC under organic wastes treatment were 15.57%-22.82%, 20.00%-38.31% and 16.30%-50.56%, respectively. (2) Among the five kinds of organic wastes, biogas residue and mushroom residue are more effectiveto the improvement of soil TOC content compared with crop straw. The areraqe annual increasing rate of soil TOC content of bioqas residue, mushroom residue, pig manure, wine residue and Crop straw were 22.82%, 21.88%, 16.42%; 16.13% and 15.57%, respectively.