不同秋耕措施对黄土高原春玉米田土壤物理质量的影响

合理耕作是改善土壤物理质量及构建合理耕层的重要措施之一,对黄土高原农田改良具有重要意义。本研究采用旋耕、深翻和深松3种秋耕措施,探究了不同秋耕措施对黄土高原春玉米田0～30 cm土壤物理质量的影响。结果表明:深翻5～30 cm各层次土壤容重较旋耕显著降低了10.1%～14.58%,土壤总孔隙度和土壤充气孔隙度则分别显著增加了11.59%～22.37%和26.52%～75.2%。深翻10～30 cm各层次土壤容重较深松显著降低了6.56%～13.48%,土壤总孔隙度则显著增加了9.3%～17.1%。深翻0～10cm各层次土壤毛管孔隙度较深松显著增加了7.41%～11.75%,10～30 cm各层次土壤质量含水量显著增加了5.46%～16.57%。此外,5～10 cm土壤固、液、气三相比偏离以旋耕最佳,10～30 cm各层次则以深翻为最佳。综合来看,旋耕改善了5～10 cm土壤物理质量,深翻改善了10～30 cm土壤物理质量,采用旋耕+深翻轮耕模式可能是该研究区构建春玉米田合理耕层的潜在措施之一。

Effects of Different Autumn Tillage Practices on Soil Physical Quality of Maize Field on Loess Plateau of China

Reasonable tillage is one of important measures to improve soil physical quality and to construct rational tillage layer on the Loess Plateau. In this study, three autumn tillage practices, including rotary tillage (RT), plough tillage (PT) and subsoiling (ST), were carried out to assess effects of different autumn tillage on soil physical quality in the 0~30 cm layer of the maize field on the Loess Plateau. The results showed that, compared with RT, adoption of PT significantly reduced soil bulk density by 10.1~14.58%, and significantly increased by 11.59~22.37% of the total porosity and 26.52~75.2% of air filled porosity in the 5~30 cm profile, respectively. Moreover, PT significantly reduced soil bulk density by 6.56%~13.48% and increased total porosity by 9.3%~17.1% in the 10~30 cm soil profile compared with ST. In comparison with ST, PT significantly increased by 7.41~11.75% of the capillarity porosity at the 0~10 cm depth and 5.46~16.57% of the mass water content in the 10~30 cm soil profile. The most optimal deviation value of solid, liquid and gas at the 5~10 cm depth under RT and at the 10~30 cm depth under PT was observed. Overall, soil physical quality was improved under RT at the 5~10 cm depth while under PT in the 10~30 cm soil profile. Therefore, adoption of RT/PT shifting tillage could be a potential practice to construct rational tillage layer in the maize field on the Loess Plateau of China.