秸秆还田与长期连作棉田土壤水稳性团聚体特征

发布时间：2018-05-28 06:39

本文选题：秸秆还田 + 长期连作　；参考：《干旱地区农业研究》2017年01期

【摘要】：以棉花长期连作定点试验田为研究对象,研究秸秆还田对长期棉花连作土壤水稳性团聚体及有机碳分布的影响。试验设长期连作5、10、20 a和30 a的秸秆还田小区及长期棉花连作5、10 a和20 a无秸秆还田小区,共计7个处理,每个处理3个重复。结果显示:无秸秆还田条件下,随着连作年限的增加,土壤1~0.25 mm水稳性团聚体含量和团聚体中有机碳含量逐渐降低,0.053 mm水稳性团聚体含量逐渐增加;而秸秆还田可以显著提高长期连作棉田土壤中1~0.25 mm水稳性团聚体含量、团聚体平均重量直径(MWD)、几何平均直径(GMD)值及团聚体中有机碳含量;秸秆还田条件下随着连作年限的增加,土壤1~0.25 mm水稳性团聚体含量逐渐增加,0.053mm水稳性团聚体含量逐渐降低,且对0~30 cm耕作层土壤影响较大;与无秸秆还田相比,秸秆还田长期连作棉田,随着连作年限的增加,团聚体分形维数(D)逐渐降低,而无秸秆还田分形维数(D)逐渐增加,团聚体分形维数表现为随土层加深而增大,最后在20~30 cm处趋于稳定。说明秸秆还田显著提高长期连作棉田水稳性团聚体的稳定性,对改善土壤结构、提升土壤的肥力具有积极作用,能够缓解长期连作对土壤物理性状产生的不利影响。
[Abstract]:The effects of straw returning on soil water stable aggregates and organic carbon distribution in cotton continuous cropping field were studied. In the experiment, there were 7 treatments with 7 treatments in which straw was returned to field for 20 years and 30 years for long term continuous cropping, and 5 years and 20 years for cotton for 5 years and 20 years, respectively, with 3 repeats in each treatment. The results showed that under the condition of no straw returning to the field, with the increase of continuous cropping years, the content of water stable aggregate and organic carbon in soil decreased gradually, and the content of water stable aggregate increased gradually with the increase of continuous cropping years. However, returning straw to field could significantly increase the content of water stable aggregates in soil of long-term continuous cropping cotton fields, the mean weight diameter of aggregates, the GMDD value of GMDs and the organic carbon content in aggregates, and the content of organic carbon in the aggregates increased with the years of continuous cropping under the condition of straw returning to the field, the average weight diameter of aggregates and the content of organic carbon in aggregates were increased with the successive cropping years. The content of water stable aggregates in soil increased gradually, and the content of water stable aggregates in 0 ~ 30 cm tillage layer decreased gradually and had a greater effect on the soil of 0 ~ 30 cm tillage layer, and compared with the return of straw, straw returning to cotton field for a long period of time increased with the increase of continuous cropping years. The fractal dimension of agglomerates decreased gradually, but the fractal dimension of returning to field without straw increased gradually. The fractal dimension of aggregates increased with the deepening of soil layer, and finally tended to be stable at 20 ~ 30 cm. The results showed that straw returning could significantly improve the stability of water-stable aggregates in long-term continuous cropping cotton fields, improve soil structure and soil fertility, and alleviate the adverse effects of long-term continuous cropping on soil physical properties.
【作者单位】：石河子大学农学院新疆兵团绿洲生态农业重点实验室;
【基金】：国家自然科学基金(31260307)
【分类号】：S562;S152

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