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在位于黄河流域半干旱区清水河县,设置免耕不同轮作方式对土壤物理性质及作物产量的影响试验。对免耕不同耕作方式下,土壤团粒结构、总孔隙度、水热变化及作物产量进行了测定。结果表明:经3 a的免耕+轮作后,土壤团粒结构,总孔隙度和水分含量均有逐年增加的趋势,其中留茬覆盖处理尤为明显。秸秆覆盖处理土壤团聚体在0.25~0.5 mm之间含量最高;常规耕作与留茬不覆盖在0.1~0.25 mm之间达到最高值。说明,留茬覆盖有利于形成大粒径的团聚体颗粒,留茬不覆盖处理对于土壤微结构的形成有良好的促进作用。同时,土壤总孔隙度在不同年际间均表现为留高茬覆盖>留低茬覆盖>留高茬>留低茬>常规耕作,可见,免耕不同轮作方式对土壤的改善有一定的积极作用。实施免耕的前2 a,作物产量不稳定,甚至造成减产,第3年免耕增产效应有所显现。
In Qingshuihe county located in the semi-arid area of the Yellow River Basin, the effects of different tillage patterns on soil physical properties and crop yield were tested. Under no-tillage and tillage, soil aggregate structure, total porosity, hydrothermal and crop yield were measured. The results showed that after 3 years of no-tillage + rotation, the soil aggregate structure, total porosity and water content tended to increase year by year, of which stubble mulching was particularly evident. Soil aggregates with straw mulching had the highest contents of 0.25-0.5 mm. Conventional tillage and stubble did not reach the maximum values of 0.1-0.25 mm. It shows that the stubble covering is beneficial to the formation of aggregates particles with large particle size. Stubble uncoated treatment has a good promoting effect on the formation of soil micro-structure. At the same time, the total soil porosity in different years showed high stubble cover> low stubble cover> high stubble> low stubble> conventional tillage. Therefore, different tillage modes of non-tillage have a certain positive effect on soil improvement effect. During the first two months of no-till farming, the crop yield was unstable and even reduced. The effect of no-till stimulation in the third year appeared.