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设2个秸秆覆盖时期(全程覆盖、生育期覆盖)和3个覆盖量(3000、6000和9000kg·hm-2),以全程不覆盖为对照,研究陕西渭北旱塬免耕条件下秸秆覆盖对小麦田土壤团聚体的影响.结果表明:在0～40cm土层,随土层的加深,>5mm径级的土壤团聚体含量逐渐增加,<5mm径级的土壤团聚体含量逐渐减小;各覆盖处理中,>0.25mm径级的机械稳定性团聚体和水稳性团聚体的含量均显著大于对照,分别增加13.0%～26.4%和18.6%～45.6%,其中,6000kg·hm-2秸秆覆盖处理的增幅最大;秸秆覆盖提高了土壤有机质含量,土壤有机质含量与>0.25mm径级的土壤水稳性团聚体含量呈显著正相关;各秸秆覆盖量处理均降低了土壤不稳定团粒指数,以6000kg·hm-2秸秆覆盖处理的土壤不稳定团粒指数最小.表明秸秆覆盖可显著增加0～40cm土层>0.25mm径级的土壤团聚体和有机质含量,提高土壤结构稳定性,并且以6000kg·hm-2覆盖量的处理效果最佳,该覆盖量可以作为渭北旱塬小麦田合理的秸秆覆盖模式应用于农业生产中.
The straw mulching period (full coverage and growth period coverage) and the three coverage (3000, 6000 and 9000 kg · hm-2) were set up. The straw mulching under no-tillage in Weibei arid plain of Shaanxi Province The results showed that soil aggregates> 5 mm in diameter increased gradually with soil depth increasing in 0-40 cm soil layer, and soil aggregates in soil <5 mm diameter scale gradually decreased in 0-40 cm soil layer. The content of mechanical stability aggregates and water stable aggregates> 0.25mm diameter in all treatments were significantly increased by 13.0% -26.4% and 18.6% -45.6%, respectively. Among them, 6000kg · hm-2 Straw mulching had the largest increase. Straw mulching increased the content of soil organic matter, and soil organic matter content had a significant positive correlation with the soil water-stable aggregates content of> 0.25mm diameter. The straw mulch treatments reduced the soil unstable aggregate index , And the index of unstable soil aggregates with 6000kg · hm-2 straw mulching was the smallest, which indicated that straw mulching could significantly increase soil aggregates and organic matter content of 0-25cm soil layer and soil structure stability, 6000kg · hm-2 coverage of the treatment If preferred, the coating amount as reasonably Weibei Dryland wheat field straw mulching mode used in agricultural production.