Study On The Nitrogen Transportation Law Of Soil Fertilization In The Gneiss Soil

Plateau and mountainous area of Hebei account for about 60% of the whole province, a total area of gneiss area of Tai-hang mountain is about 12,000 km2, accounting for 42% of the total area of Tai-hang mountain, is one of larger gneiss area that concentrating distribution in China . At present, study the impact of nitrogen fertilizer on soil, crop yield and soil profile of nitrate accumulation and leaching on the plains are more than mountain soils, especially gneiss new fertilizer to the soil and millet growth process nitrogen spatial and temporal distribution in the soil profile. In this paper, use the research methods that a combination of the field plot and column leaching method, take the Baoding Tang County Villa mountain new cultivated gneiss farmland soil and millet as teste crops and test soil, studied the impact that a variety of fertilization treatment on millet growth and soil nitrogen spatial and temporal distribution, the purpose was to ascertain the impact the distribution of different nitrogen levels on soil nitrogen in space and time in the process of crop growth, Providing a theoretical basis for the development of the ecological safety of the fertilization program, control gneiss mountains of agricultural nonpoint source pollution and protect watershed ecological environment. The main conclusions are as follows:1.Total nitrogen were significantly decreased on soil fertilization in each fertilizer treatment.In the same fertilizer treatment, soil nitrate content with increasing amount of nitrogen increases.In the same fertilizer levels, combined application of organic manure and chemical fertilizer treatments 20-60 cm soil layer of NO₃^--N content was significantly lower than the single application of urea and inorganic fertilizer treatment on whole growth period of millet.It indicate that combined application of organic manure and chemical fertilizer treatments can coordinate the supply of soil nitrogen, and significantly reduce the content of the soil NO₃^--N, reduce the migration of nitrate down to the bottom of soil at the same time.2. In the soil column leaching method, nitrogen fertilizer moved below 90 cm with water in the soil at the end of the leaching.Combined application of organic manure and chemical fertilizer treatments can inhibite the release of fertilizer nutrient leaching and ammonium nitrogen into nitrate has a certain degree of inhibition. After the end of the leaching of organic fertilizer soil NH₄⁺-N and NO₃^--N content was significantly higher than the treatment of urea applicantion, have a role in organic fertilizer for the suppression of the soil of NH₄⁺-N, NO₃^-- N down.3. Different layers of ammonium nitrogen in all fertilization treatments were significantly higher than the control, ammonium nitrogen in the soil seedling stage was significantly higher than the jointing stage, and jointing stage was significantly higher than later growth period. Heading stage, filling and harvesting of ammonium nitrogen in the soil are maintained at a relatively low level, and different fertilization treatments and different soil ammonium nitrogen, there was no significant difference.4. Under this experiment condition, compared with the control, all nitrogen treatments had significantly increased the yield of millet. The nitrogen rate was 120 kg/hm2, the yield of millet reached the highest, while the output ratio are the highest when nitrogen application rate of 120 kg/hm2, deal with applying combination with organic manure. Fertilizer nitrogen use efficiency and nitrogen fertilizer agronomic efficiency was the highest application of combination with organic manure. The millet production in the gneiss entisols, it was suggested that fertilization adopted nitrogen rate of 120 kg/hm2 and combination with organic manure.