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采取田间定位试验与室内分析的方法,研究了有机稻蟹、常规稻蟹和单作水稻3种模式对土壤团聚体组成、各级团聚体中有机碳的分布、团聚体中腐殖质组成和胡敏酸光学性质的影响。结果表明:不同模式下团聚体含量均随粒级的减小表现为先升高后降低的趋势,2~0.25mm为优势粒级团聚体,所占比例高达46.73%~51.56%;与常规稻蟹模式和单作水稻模式相比,有机稻蟹模式可明显提高各级团聚体内有机碳以及胡敏酸碳(HAC)和富里酸碳(FAC)的含量。有机稻蟹模式各级团聚体中有机碳含量较单作水稻模式分别提高59.40%、64.44%、23.46%和15.88%;与单作水稻模式相比,有机稻蟹模式2~0.25mm和<0.053mm粒级团聚体中HAC含量明显增加,增幅分别为31.10%和30.82%;有机稻蟹模式和常规稻蟹模式2~0.25mm和<0.053mm粒级团聚体中FAC含量较单作水稻模式均显著提高,分别为56.26%、17.80%和27.58%、22.47%;有机稻蟹模式各级团聚体中胡敏酸(HA)的Δlog K值最高,标志着HA分子向新成化方向发展。因此,有机稻蟹模式不仅可以增加各级团聚体中有机碳的数量,而且能够改善土壤腐殖质品质,提高土壤肥力。
Taking the methods of field experiment and laboratory analysis, the effects of organic rice crab, conventional rice crab and single rice on the composition of soil aggregates, the distribution of organic carbon in the aggregates at various levels, the composition of humus in the aggregates, Effect of acid optical properties. The results showed that the content of aggregates increased firstly and then decreased with the decrease of grain size in different patterns, with the proportion of 2 ~ 0.25mm as dominant grain aggregates, accounting for 46.73% ~ 51.56% Compared with monoculture rice model, the organic rice crab model could significantly increase the content of organic carbon, humic acid carbon (HAC) and fulvic acid carbon (FAC) in aggregates. Compared with monoculture rice model, the contents of organic carbon in organic rice crabs increased by 59.40%, 64.44%, 23.46% and 15.88% The HAC content in the aggregates of mm-particle aggregates increased significantly by 31.10% and 30.82%, respectively. The contents of FAC in the aggregates with organic aggregates of 2 ~ 0.25mm and <0.053mm were both Significantly increased, respectively, at 56.26%, 17.80% and 27.58% and 22.47%, respectively. The highest Δlog K value of HA in the aggregates of organic rice and crab at each stage indicated that the HA molecules developed towards new formation. Therefore, the organic rice and crab mode can not only increase the amount of organic carbon in aggregates at all levels, but also improve the quality of soil humus and soil fertility.