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通过3年的田间定位试验,系统的研究了稻草不同途径还田对稻田土壤容重、孔隙度、团聚体、有机碳总量、腐殖质组成及腐殖质结合形态的影响。结果表明,与无肥(CK)及纯施化肥(NPK)对照相比,稻草直接深埋还田(NPK+S)及利用后的菌渣、牛粪、沼渣深埋还田(NPK+FD、NPK+CD、NPK+BD)均能一定程度的降低土壤容重、增加孔隙度、增加>0.25 mm水稳性团聚体的数量和提高土壤团聚体的稳定性,有利于形成和保持良好的土壤结构;同时能提高土壤腐殖质中胡敏酸含量和HA/FA比值,增加松结态腐殖质含量和提高松/紧腐殖质比值,能一定程度的改善土壤腐殖质的组成、性质及结合形态,提高腐殖质品质,不过这4个处理间的差异不明显。稻草焚烧还田(NPK+S′)在以上方面效果均不显著,且带来严重的大气污染,并不可取。
Through three years of field experiment, the effects of different ways of straw on soil bulk density, porosity, aggregates, total organic carbon, humus composition and humus binding morphology were systematically studied. The results showed that compared with CK and NPK control, the straw was directly buried in the field (NPK + S) FD, NPK + CD, NPK + BD) could reduce the bulk density of the soil to some extent, increase the porosity, increase the number of water-stable aggregates> 0.25 mm and improve the stability of soil aggregates, which is good for the formation and maintenance of good Soil humus content, humic acid content and HA / FA ratio of soil humus, increasing the content of pine knot humus and increasing the ratio of loose / tight humus, which can improve the composition, properties and combination morphology of soil humus to a certain extent, Quality, but the difference between the four treatment is not obvious. It is not advisable that the straw burning and returning to the field (NPK + S ’) is not effective in the above aspects and causes serious air pollution.