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该文以1990年建立的耕作制定位试验田紫色水稻土为研究对象,分析了冬水田(FPF)、水旱轮作(CR)和垄作免耕(RNT)3种耕作方式对土壤团聚体组成和有机质的影响。结果表明,垄作免耕减少了对土壤大团聚体的破坏,在0～10cm土层,垄作免耕大团聚体含量分别是冬水田和水旱轮作的1.48和1.32倍,微团聚体含量则显著降低;在>10～20cm土层有相同的趋势。3种耕作条件下,有机碳和氮在团聚体中的分布模式类似,均有向大团聚体富集的趋势,但垄作免耕条件下土壤有机碳和氮质量分数显著高于冬水田和水旱轮作。对土壤颗粒有机质(POM)的分析结果表明,垄作免耕0～10cm土层轻质组分(LF)的质量分数(1.92g/kg)与水旱轮作(1.70g/kg)差异不显著,但显著高于冬水田(1.42g/kg)。冬水田、水旱轮作和垄作免耕的0～10cm土层,团聚体内总颗粒有机质(totaliPOM)质量分数分别为0.96,1.12,2.14g/kg;垄作免耕土壤团聚体内细颗粒有机质(fineiPOM)分别为冬水田和水旱轮作土壤的3.02和2.46倍,占总POM差异的57%和66%。垄作免耕土壤团聚体内粗颗粒有机质(coarseiPOM)分别为冬水田和水旱轮作土壤的1.56和1.40倍,占总POM差异的18%和19%。在>10～20cm土层有相似的趋势,但在>10～20cm层土壤粗iPOM的差异对总POM差异的贡献较0～10cm层大。垄作免耕减少了对大团聚体的破坏并促进微团聚体向大团聚体团聚;降低了团聚体的周转速率,促进了细iPOM的固定,利于紫色水稻土对碳的固定和积累。
In this paper, a pilot farming system of purple paddy soil was established in 1990 to analyze the effect of three tillage practices of winter paddy field (FPF), water and drought rotation (CR) and ridge tillage (RNT) on soil aggregate composition and organic matter Impact. The results showed that ridge-tillage and no-tillage reduced the damage to the soil aggregates. In the 0-10 cm soil layer, the content of big-tillage and no-tillage macrophytes was 1.48 and 1.32 times that of the winter paddy field and the drought and drought rotations, respectively. The content of microaggregates was significant Lower; in> 10 ~ 20cm soil layer have the same trend. Under the three tillage conditions, the distribution pattern of organic carbon and nitrogen in the aggregates was similar, and the enrichment tendency towards large aggregates tended to increase. However, under no tillage conditions, the soil organic carbon and nitrogen contents were significantly higher than those in winter paddy field and water Dry rotation. The results of soil organic matter (POM) analysis showed that there was no significant difference in the mass fraction (1.92g / kg) of light fraction (LF) of 0-10cm soil layer between ridge and no-tillage with the rotation of 1.70g / kg, But significantly higher than that of winter paddy field (1.42g / kg). The soil total organic matter (totaliPOM) in the aggregates was 0.96, 1.12 and 2.14 g / kg, respectively. The fine-particle organic matter (finei-POM) Respectively, 3.02 and 2.46 times of winter paddy fields and irrigated fields, accounting for 57% and 66% of the total POM. The coarse-grained organic matter (coarseiPOM) in the ridge-tillage and no-tillage soil aggregates was 1.56 and 1.40 times of that in winter paddy field and irrigated and up-rotation respectively, accounting for 18% and 19% of the total POM difference. The trend of> 10-20 cm soil layer is similar, but the difference of crude iPOM in> 10-20 cm soil layer contributes more to the difference of total POM than that of 0-10 cm soil layer. Ridge-tillage reduces the damage to large aggregates and promotes the reunion of microaggregates to large aggregates; reduces the turnover rate of aggregates, promotes the immobilization of fine iPOM and favors the fixation and accumulation of carbon in purple paddy soils.