秸秆还田对玉米产量和土壤团聚体组成及有机碳分布的影响

Effects of Straw Returning on Yield and Soil Aggregates Composition and Organic Carbon Distribution

研究秸秆还田对土壤团聚体组成、有机碳分布及玉米产量的影响,为秸秆合理利用与土壤培肥提供科学依据。采用田间定位试验的方法,研究秸秆还田（SNPK）和生物炭还田（BNPK）处理对玉米产量,土壤团聚体组成及其有机碳分布的影响。结果表明,与常规施肥相比,SNPK和BNPK处理4年后玉米产量分别提高6.95%和4.83%;SNPK和BNPK处理均提高了0～20 cm土层〉2 mm团聚体含量,降低〈0.25 mm团聚体含量,均降低21～40 cm土层中〉2 mm团聚体含量;SNPK处理提高0～20 cm土层有机碳含量14.11%,BNPK处理对土壤有机碳提高不明显,二者均提高0～20 cm土层中0.25～1 mm和〈0.25 mm粒级中的有机碳含量;SNPK处理明显提高0～20 cm土层〉2 mm粒级团聚体对有机碳的贡献率,BNPK处理对各粒级团聚体对有机碳的贡献率影响不明显。长期秸秆还田和生物炭还田能够改变土壤团聚体的分布,有利于土壤结构的形成,提高土壤固碳能力,增加玉米产量。

A field experiment was conducted to determine the effects of straw returning on soil aggregate compo-sition, organic carbon distribution and maize yield, in order to provide scientific basis for rational utilization of strawand improvement of soil fertility. The effects of straw returning on maize yield, soil aggregate composition and organ-ic carbon distribution under different treatments of straw returning（SNPK） and biochar returning（BNPK） were stud-ied. The results showed that, compared with conventional fertilization, the yield of maize increased by 6.95% and4.83% after straw returning and biochar returning to field for 4 years. Straw returning and biochar returning to fieldincreased the content of 〉2 mm aggregate in the 0-20 cm soil layer, and decreased the content of 0.25 mm aggre-gate, and both decreased the content of〉 2 mm aggregate in the 20-40 cm soil layer. Straw returning increased thecontent of the organic carbon by 14.11% in 0-20 cm soil layer, but biochar returning can not obviously increase soilorganic carbon, both improved the content of the organic carbon at 0.25-1 mm and 〈0.25 mm aggregates in 0-20 cmsoil layer. Straw returning obviously increased the contribution rate of organic carbon at 〉2 mm aggregate in the 0-20 cm soil layer, but biochar returning can not obviously increase the contribution rate of organic carbon at differentgraded aggregate. In general, long-term straw returning and biochar returning could change the distribution of soilaggregates, which was beneficial to the formation of soil structure, improve the ability of soil carbon sequestrationand increase the yield of maize.