Analysis of characteristics of soil aggregates at different slope positions of typical black soil sloping farmland in Northeast China
"Manchuan Mangang" is a typical landform in the black soil area of Northeast China, and its typical black soil structure is seriously affected by runoff, freeze-thaw and other effects. In order to explore the distribution characteristics of soil aggregates in black soil sloping farmland in Northeast China, soil samples were collected from bottom slope position, middle slope position and top slope position. Water stable aggregates particle size distribution, stability index and soil properties under different slope positions were investigated. The relationship among water stable macroaggregate, soil pH, organic matter and calcium-magnesium ratio, and the relationship between stability index and aggregate particle size were analyzed. The results showed that the water stable aggregates particle size under different slope positions all dominated by＜0.25 mm aggregateand the aggregate content of＞2 mm accounts for the least. Aggregates with the size of ＜0.25 mm are significantly higher in the bottom slope than in the middle and top slope (P＜0.05), and aggregates with the size of 0.25-0.5 mm, 0.5-1 mm, 1-2 mm and ＞2 mm were significantly higher in the top slope than in the bottom slope (P＜0.05). The average weight diameter and geometric average diameter were top slope＞middle slope＞bottom slope, among which the bottom-position of the slope was significantly different from the top position and the middle position of the slope (P＜0.05), and the water stability of aggregates was top slope＞middle slope＞bottom slope. Average weight diameter and geometric average diameter were positively correlated with ＞0.25 mm aggregates and negatively correlated with ＜0.25 mm aggregates, among which＞2 mm aggregates were the most affected (P＜0.01). Soil organic matter, pH and calcium-magnesium ratio were positively corrected with ＞0.25 mm aggregates (P＜0.05). Therefore, the high organic matter content was conducive to the formation of ＞0.25 mm aggregates on typical black soil sloping farmland, improving the water stability of aggregates.
water stable macroaggregatesloping farmlandmean weight diametergeometric mean diameterblack soil
万方数据
维普
