耕作方式对黑土硬度和容重的影响

以吉林省德惠市8年黑土田间定位试验的小区土壤为研究对象,对不同耕作方式下土壤硬度和容重进行研究.结果表明:免耕增加了土壤硬度,主要表现在2.5 ～17.5 cm土层；在玉米连作和玉米-大豆轮作下,苗眼处免耕处理的最大土壤硬度分别为2816和1931 kPa,秋翻处理下分别为2660和2051 kPa,对作物生长均没有限制作用；秋翻处理的土壤硬度曲线随垄形而变化,免耕处理的土壤硬度曲线起伏较小.与秋翻相比,免耕显著增加了5～20 cm土层的土壤容重.5 ～ 30 cm土层的土壤容重在免耕处理下变化幅度较小,在秋翻处理下随土壤深度的增加逐渐增大.土壤容重与土壤硬度之间相关性不显著.

Effects of tillage mode on black soil's penetration resistance and bulk density

Taking an eight-year field experiment site in Dehui County of Jilin Province, Northeast China as test object, this paper studied the effects of different tillage modes (no tillage and ploughing in autumn) on the penetration resistance and bulk density of black soil. No tillage increased the soil penetration resistance, especially at the soil depth of 2.5-17.5 cm. In the continuous cropping of maize and the rotation of maize-soybean, the maximum soil penetration resistance at planting zone under no tillage and ploughing in autumn was 2816 and 1931 kPa, and 2660 and 2051 kPa, respectively, which had no restriction on the crop growth. The curve of soil penetration resistance under ploughing in autumn changed with ridge shape, while that under no tillage changed less. Comparing with ploughing in autumn, no tillage increased the bulk density of 5-20 cm soil layer significantly. Under no tillage, the bulk density of 5-30 cm soil layer changed little, but under ploughing in autumn, soil bulk density increased gradually with increasing soil depth. There was no significant correlation between soil bulk density and soil penetration resistance.