The Transformation Process And Ammonia Volatilization Losses Of Nitrogen In Xinjiang Salinization Soil

Saline soil is one important type of soil resources in arid and semi-arid areas. The development and utilization of saline soil has been paid more and more attention. At the same time, saline soil is also a special ecosystem. The existence of excessive salt seriously impacts the soil physical, chemical and biological characteristics, furtherly, affecting the transformation of soil nutrients, espicialy nitrogen losing. Ammonia nitrogen loss is an important way to calcareous soils, and it is more serious in saline soil than in non-salinization soil. Xinjiang is located in the hinterland of the Eurasian continent, because of the arid desert climate, water shortage, crop varieties with high salt-tolerant and reclaimation of saline soil in a large scale, the cultivated land with high salt contents will exist for a long time. To study the transformation process of nitrogen in saline soil can provide a theoretical basis for utilization of improving nitrogen fertilizer and a more rational use of saline soil resources and protect the ecological environment. This search selects the typical saline soils in northern and southen Xinjiang as samples, using phosphoric acid glycerol - sponge ventilation method simulation test in the indoor to study the relations between nitrogen transformation process and ammonia loss in the salinization soil. The main conclusions are as follows:(1) Ammonin loss has not been tested when the same amount of urea added into different salt treatment deionized water. The results show that amide form of nitrogen and salt ions will not lead to the volatile ammonia.(2) The experiments with changing the salt content and pH value of soil samples, simulating the typical soil samples with the same salt content and pH value have been done to study how the salt and pH to influence urea hydrolysis and conversion process and ammonia loss. The results show that urea hydrolysis is not significant in salinization soil of urease, which means with increasing of the total salt content and pH, it restraines the urease activity, but promotes the volatile ammonia. Soil ammonium concentrations and ammonia volatilization have a better correlation, soil total salt content and pH value effect on nitrification significantly, to make ammonium nitrogen content in soil increased greatly, which brings a large number of volatile ammonia lossed.(3) The tests to study the ammonia volatilization loss characteristics of different types of nitrogen fertilizer in typical non-salinization soil, saline soil, alkaline soil have been dong.The results show that nitrogen amounting for about 1.34% to 27.74% of the total fertilization Iosse in the form of NH3. The type and extent of soil salinization affect the evaporation rate of ammonia significantly. The existence of excessive salt is the main reason to inhibite nitrogen nitrification, which causes the soil nitrogen ammonia volatilization loss increasing.