耕作措施对0~20cm土壤容重影响较大,深层影响较小。稳定入渗率呈现出强烈的时间变异性,从整个生育期看,翻耕都表现出较高的稳定入渗率,随时间的变化,差异减小;不同负压下,翻耕稳定入渗率最高,免耕次之,铁茬最低,不同时期变化趋势一致;翻耕大孔隙较其它两耕作措施多,翻耕后,土壤大孔隙增多,比免耕和铁茬处理高65%左右,达到5%水平差异显著,免耕与铁茬差异不显著。随着时间的推移,不同耕作措施大孔隙比例有所下降,中小孔隙比例增加,大孔隙数目翻耕仍最高,从显著性看,与免耕和铁茬在5%水平显著。

The influence of tillage on bulk density of the surface soil (0~20cm) was stronger than on that of the subsoil. Soil infiltration rate varied greatly with the time and tillage. The infiltration rate under conventional tillage was the highest among the treatments in the summer corn growth season, but the differences between the treatments got smaller along with the time. In terms of infiltration rate under different water tension conventional tillage was the highest and non-tillage the second, direct drilling the lowest, and the trend was the same with different growth seasons of the summer corn. The number of macropores under conventional tillage was 65% more than that of non-tillage and direct drilling, reaching the 5% significance level, but the difference between non- tillage and direct drilling not significant. As time went on, the number of macropores reduced and the number of mid-, micropores increased. But the number of macropores under conventional tillage still was the highest, at 5% significance level over that under non-tillage and direct drilling.