Effect Of Biochar On The Transportation Of Nitrate And Ammonium In The Different Soils

In recent twenty or thirty years, as the population continues to increase, the city scale expands unceasingly, the cultivated land area is reduced, makes the land continue to increase, multiple cropping index and the kind of the low soil fertility, can only rely on fertilisers to increase crop yield per unit. According to the survey by the world bank, world grain production has gained40%by increasing fertilizer application, the dosage of fertilizer is most nitrogen fertilizer. Nitrogen fertilization is large in China, and its dosage accounted for a quarter of the world’s nitrogen fertilizer. Of nitrogen fertilization on crop growth has played a positive role.Fertilizer nitrogen mainly in the form of NH4+and NO3-absorbed by plants (Zhang Jiheng2002; Yao Chunxia, etc.,2005). However, with the increase of nitrogen fertilizer use, nitrogen loss caused by surface water body eutrophication, quality decline of agricultural products and a series of food and environment problem increasingly serious, and increasingly brought to the attention of the people.In order to improve nitrogen use efficiency and reduce the loss of ammonium nitrogen and nitrate nitrogen in the aquatic environment pollution, this paper add biochar in soil to improve soil, lock the nitrogen, phosphorus and other nutrients and moisture, promote plant growth. For understanding biological carbon particle size and add the proportion of different types of soil nitrogen ability to lock the influence of the size, this article selects three kinds of typical loess plateau (yulin) sand soil, yellow soil spongy soils (northern shaanxi ansai), cultivated loessial soil was larger than that (yangling), three different diameter (2～1mm,1～0.25mm,<0.25mm)4add ratio (0,2%,5%,8%,) the biological carbon as the research object, studies the biological carbon adding proportion were0%,2%,5%and0%respectively in three different types of soil ammonium nitrogen and nitrate nitrogen breakthrough curve.The results show that the(1) under the condition of water saturation, three kinds of soil nitrate nitrogen and ammonium nitrogen breakthrough curve (R2of0.87or higher) conforms to the convection diffusion equation, the migration process and biological carbon add significant correlation (P <0.05).(2) for the typical loess plateau soil (sand soil, yellow spongy soils, cultivated loessial soil was larger than that) in terms of biochar addition can reduce nitrate nitrogen and ammonium nitrogen penetration ability, increase the penetration time, delayed migration through the point.(3) compared with2%and5%of biochar addition proportion, biochar added8%, the effect is most obvious; But for cultivated loessial soil was larger than that of biochar addition can increase nitrate instead of penetration, reduce the penetration time, make the migration through the points in advance. At the same time, also is the biological carbon added8%, had the greatest effect.