The Relation Of N And P Nutrient Character In Phaeozem Surface Runoff And Fertility Degeneration

Phaeozem is a major cultivated soil in china. At present, with the development of land, there appear many phenomenon that soil structure was deteriorating, soil was getting hardened and impervious, black soil layer was getting thinner. As far as the process and the environment effect of nitrogen and phosphorus biology geochemistry cycle on the earth surface are concerned, it is an important content in the region study about the globe changes with double drive of man and nature effect. N and P fertilizers applied is one of the greatest effective measures that improve the grain yields in china,, but it lead to anxious environment problem. Phaeozem is worldwide for fertile and high yield. Now it had been changed gully and ditches for large soil erosion. Some experts think Phaeozem would be disappeared in fifty years if let soil erosion go unchecked. While it not only lead to soil fertility degeneration, but ecology problems. At last, only left loess clay that can seldom grow crop.In light of current using situation and drawing on the experience of many scholars researched methods and viewpoints, This thesis made com land, fallow land, orchard, grass land as experimental field in black soil region JLAU, which carried out experiment by applying different amounts of N and P fertilization in corn field. By means of collecting the samples of rainfall runoff, erosion silt and surface layer soil before and after rainfall for one year nature precipitation in field, we study the effect of surface runoff on N and P nutrient and fertility degeneration. The results showed:(l)There are lots of factors which affect soil erosion and losses of N and P, in which rainfall and rainfall intensity were more important, while rainfall intensity is the most important meteorological phenomena factor. The study showed that N and P runoff concentrate in storm is higher that norm. With the cover level increasing and different utilization manners, Losses of N and P nutrient showed notable divergence. (2) With the increasing of rainfall and rainfall intensity, Losses amounts of runoff silt in fallow field, com field and orchard field showed rising, while was stable in grass field. (3) With cover level increasing, losses amounts of runoff silt and N and P in silt increased. (4) With cover level increasing, TN in soil and silt decreased, but NH₄-N+NO₃N in runoff didn't reduced. (5) With increasing amounts of N and P fertilization, there weresome effect on losses of N and P fertilization. With increasing amounts of N, TN in soil and runoff both increased, while with increasing amounts of P, TP in runoff and silt increased, did DP in runoff increase.Absolute amounts of soil erosion is not large for the falling gradient in black soil region, but the nutrient is high in erosion soil, the nutrient of erosion soil and runoff is high, which leads to soil fertility degeneration, while N and P nutrient pour into water with surface runoff, it leads to water nutrient enrichment and pollution, and becomes one of confined factors of water nutrient enrichment. Soil nutrient erosion and water pollution is a widespread problem which worldwide countries face, people have been thought highly of it. Soil and water erosion is serious in the Yellow River in China, amounts of nutrient run off with surface runoff and silt, which leads to soil fertility degenerate .So agriculture ecosystem is in vicious cycle in this area. According to the research of black soil surface runoff of N and P nutrient characters and soil fertility degeneration, it discussed the relationship of runoff milt and soil nutrient erosion in black region, and provided foundation for environment protecting, pollution controlling, nutrient apprising, protecting, and prevention and cure. It helps to improve people's awareness, control and decrease soil nutrient erosion, strengthen soil resources and environment protection .It can get obvious economy and ecology benefits, it is also the key point to implement ecology province, and it can play an important part in contrast superiorit...