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用人工模拟降雨器对黄土高原冬小麦收获后6个耕作措施:不翻耕(NT),不翻耕+覆盖(NTC),浅翻耕(LT),浅翻耕+覆盖(LTC),深翻耕(DT),深翻耕+覆盖(DTC)处理下土壤的入渗进行了研究,测定了土壤表面结皮、粗糙度等指标因子。结果表明,在模拟降雨强度为66 mm/h的条件下,覆盖处理的稳定入渗率>60 mm/h,降雨开始的40 m in内,平均入渗量>93%;深翻耕(DT)的稳定入渗率(26.4 mm/h)是浅翻耕(LT)(13.0 mm/h)的2倍,是不翻耕(NT)(6.4 mm/h)的4.1倍,降雨历时20m in时,深翻耕(DT)和浅翻耕(LT)分别比不翻耕处理(NT)减少径流28%和7%,40 m in时,浅翻耕(LT)和不翻耕(NT)处理径流量相当,深翻耕(DT)比这两个处理减少径流30%左右,土壤翻耕后在前期能提高土壤的入渗率,表现出经长年耕作后土壤退化的强烈特征,是“耕地越深,入渗越快”观念的根源;地表结皮是影响降雨入渗的主要因素,覆盖等保护性耕作更有利于土壤入渗。
The results of six tillage measures after winter wheat harvesting in the Loess Plateau were simulated with artificial rainfall simulator: NT, NTC, LT, LTC, The soil infiltration under tillage (DT), deep tillage + cover (DTC) was studied, and the index of soil surface crust and roughness were measured. The results showed that under the conditions of simulated rainfall intensity of 66 mm / h, the stable infiltration rate of the covering treatment was> 60 mm / h and the average infiltration rate was> 93% within 40 mins of the beginning of the rainfall. ) Was twice that of shallow tillage (LT) (13.0 mm / h) and 4.1 times of non-tillage (NT) (6.4 mm / h) (DT) and shallow tillage (LT) decreased runoff by 28% and 7%, respectively, compared with no tillage (NT) The run-off volume was equivalent. DT was 30% less than the two treatments. After tilling, the infiltration rate of soil was increased in the early stage of tillage and showed strong characteristics of soil degradation after long-term tillage “The deeper the arable land is, the faster the infiltration” is. The surface crust is the main factor that affects rainfall infiltration. Covering other types of conservation tillage is more conducive to soil infiltration.