Abstract:
Considering the change in soil physical properties caused by long-term rotary tillage such as lower plough layer and higher bulk density in the northeast corn belt, rotational tillage system were conducted in the black soils of the central and southern Songnen Plain, which is of great importance to improve soil physical properties. The experiment was set up two tillage systems: consecutive rotary tillage (R), deep ploughing-rotary tillage (D), in combination with two fertilizer managements: chemical fertilizer (T), chemical fertilizer + organic fertilizer (M). Soil moisture content, bulk density, soil compaction at 0-50 cm soil depth and soil temperature at 10 cm, 20 cm and 30 cm soil depth were determined. The results showed that deep ploughing-rotary tillage significantly increased soil temperature at 20 and 30 cm soil depth during maize seedling stage and improved the soil moisture content at 15-50 cm soil depth in each growth stage. The application of organic fertilizer could increase the soil moisture content during the seedling and harvest stage. The soil bulk density and compactness at 15-50 cm soil depth under deep ploughing-rotary tillage were significantly reduced and the addition of organic fertilizer in this treatment significantly reduced the soil bulk density at 0-50 cm soil depth, which meets the requirement of breaking the plough pan layer. However, the application of organic fertilizers in consecutive rotary tillage only significantly decreased the soil bulk density at 0-15 cm soil depth. Correlation analysis indicated that the soil moisture content was negatively correlated with soil temperature (
P > 0.05). The soil bulk density had a significant negative correlation with soil temperature under deep ploughing-rotary tillage (
P < 0.01). It could be concluded that deep-rotary tillage could decrease soil bulk density and compaction, regulate soil temperature, improve soil moisture content. Therefore, the deep ploughing-rotary tillage with the addition of organic fertilizer and chemical fertilizer is a promising strategy in improving soil physical properties in black soils of Northeast China and similar regions.