黑龙江海伦地区垦殖前后典型黑土剖面主要养分元素垂直分布特征

垦殖前后典型黑土主要养分元素特征研究对东北黑土资源的可持续利用和保护东北大粮仓具有重要作用.在松嫩平原东部海伦地区对比研究了典型黑土区40年间土地利用未发生改变的地区（本次对比研究林地和耕地），布设了4条典型黑土剖面，对垦殖前后典型黑土剖面中土壤肥力的主要指标元素（有机质、全氮、全磷、C：N及pH值）分别对比分析.结果表明：有机质、全氮、全磷含量表现为随土壤深度急剧下降—缓慢下降—基本稳定的变化趋势；垦殖虽然改变了各土层土壤中养分元素的含量，但是并未改变其随土壤深度的变化规律；垦殖在一定程度上影响了表层黑土土壤的pH值，导致耕地表层黑土土壤慢慢酸化.研究结果可为黑土资源的可持续利用、保护及修复提供科学依据.

VERTICAL DISTRIBUTION OF MAJOR NUTRIENT ELEMENTS IN TYPICAL BLACK SOIL SECTIONS IN HAILUN,HEILONGJIANG PROVINCE: Before and After Reclamation

The study on the characteristics of major nutrient elements in typical black soil areas before and after reclamation is important for sustainable utilization of black soil resources and protection of the breadbasket in Northeast China. Four sections are laid out in the typical black soil areas where land use has not changed for the past 40 years in Helen area, eastern Songnen Plain, to make a comparative study on the main index elements for soil fertility (organic matter, total nitrogen, total phosphorus, C:N and pH value) in the sections before and after reclamation. The results indicate that the contents of organic matter, total nitrogen and total phosphorus show a change trend of rapid decrease through slow decrease to basically stable with soil depth. Although reclamation has changed the content of nutrient elements in soil, it does not change the content variation rule with soil depth. Reclamation affects the pH value of black topsoil to a certain extent, which led to slow acidification of cultivated land. The research results will expectedly provide scientific basis for sustainable utilization, protection and restoration of black soil resources.