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为阐明早稻与晚稻生长期土壤水稳性团聚体分布及其稳定性对秸秆还田的响应,以福州平原红壤水稻田为研究对象,对秸秆还田后早稻田和晚稻田土壤水稳性团聚体分布特征及其稳定性,包括粒径>0.25 mm团聚体的百分含量R0.25、平均质量直径(MWD)、平均几何直径(GMD)和分型维数(D)进行测定与分析.研究结果表明,秸秆还田和对照样地,0~40 cm土层中早稻与晚稻生长期土壤均表现为水稳性团聚体组成以微团聚体(<0.25 mm粒级团聚体)为主,团聚体粒级越大,含量越少;秸秆还田对0~40 cm土层中早稻田土壤水稳性大团聚体和微团聚体总含量的影响均不显著,但秸秆还田显著增加了晚稻田土壤水稳性大团聚体(粒径>0.25 mm)含量(p<0.05),并显著减少了土壤水稳性微团聚体含量(p<0.05);秸秆还田对早稻田土壤水稳性团聚体MWD、GMD和D值影响均不显著,但显著增加了晚稻田土壤水稳性团聚体MWD和GMD值,显著降低了土壤水稳性团聚体D值(p<0.05);秸秆还田对早稻田土壤水稳性团聚体稳定性影响不显著,但显著增加了晚稻田土壤水稳性团聚体稳定性(p<0.05).
In order to elucidate the distribution of soil water-stable aggregates and the stability of soil water-stable aggregates in early rice and late rice growth stages and their responses to straw returning, the red soil paddy fields in Fuzhou Plain were used as research objects. Distribution characteristics and their stability, including the percentage of aggregates> 0.25 mm, the average mass diameter (MWD), the average geometric diameter (GMD) and the type dimension (D) The results showed that the composition of water-stable aggregates was mainly composed of micro-aggregates (<0.25 mm aggregates) in the soil layers of 0-40 cm soil layer and the late-growing rice plants in both straw returning and control plots. The larger the grain size is, the less it is. The effect of straw incorporation on the total content of soil water-stable macroaggregates and microaggregates in the 0-40 cm soil layer is not significant, but straw returning significantly increases the rate of late rice Soil water-stable macroaggregates (particle size> 0.25 mm) content (p <0.05) and soil moisture-stable microaggregate content (p <0.05) MWD, GMD and D values were not significantly affected, but significantly increased the soil water-stable aggregates MWD GMD decreased significantly the soil water stable aggregates D (p <0.05); straw returning had no significant effect on the stability of soil water-stable aggregates in the early paddy soil, but significantly increased the stability of soil water-stable aggregates in the late rice paddy Sex (p <0.05).