Effects Of Granulation And Coating On Nutirent Release Characteristics Of Organic Fertilizers

Nitrogen (N), phosphorus (P), potassium (K) are the most important nutritive elements in the growth process of the plants, not only can they enhance the crops'output, but also can they improve the crops'quality. The plant may enhance these three nutrition absorption supporting from utilizing fertilizer. However in the process of the employment of fertilizer, the outflow of effective component can affect the output of crops. In addition, this kind of frequent outflowing also cause many environment problems easily. For instance, the nutritive elements runoff function can arouse the eutrophication problem on the water, and the percolation may bring ground water deleterious substance exceeding the allowed figure and etc.The article has carried on the summary to the characteristic of chemical fertilizer and organic fertilizer, the function of employing chemical fertilizer and organic fertilizer and their respective existent problems. The essay elaborated the vital significance on reasonable employment of organic fertilizer from the angle of China's present situation on organic fertilizer employment and the future trend of development. In order to unfold the nutritive elements leakage loss under the flooded condition after utilizing organic fertilizer that was granualated and coated, and differences on metal trace element content on different soil layers, by using the laboratory simulation raise experiment, the density of nitrogen, phosphorus and potassium in the soil leakage liquid was determined, as well as the vertical distribution condition in soil of the trace elements including iron, manganese, copper, zinc. Through the data statistical analysis, main results were obtained as following:1,Along with the increase in fertilization, nutrient content in the soil liquid leakage increased at a descending rate. Fertilization increased, differences in the nutrient content of soil leaking liquid as applying granular organic fertilizer and powder organic fertilizer, on the contray, decreased. Fertilization had a little effect on Nitrate release. The nitrate content of soil leaking liquid in the application of powder organic fertilizer had always been higher than the application of granular organic fertilizer.2,The application of organic manure had a large influence in the nutrient leakage at different depths of the soi. Organic fertilizer applicated on the surface combined with a submerged soil can control the nutrient leakage and reduce ammonia, inorganic phosphate and potassium leakage losses to a certain extent.3,There are differences in the nutrient release characteristics of Coated organic fertilizer and Uncoated organic fertilizer. The nutrient supply capacity of Coated organic manure inferior to Uncoated organic fertilizer in the short term, but greater than it in the later. The envelopeof organic fertilizer enhanced the slow-release performance of fertilizer to a certain extent.4,Using Coated organic fertilizer on gray-wet soil improved the contents of effective Fe, Mn, Cu and Zn to some extent. The application of Uncoated organic manure on gray-wet soil increased the content of effective Fe, Mn, however effective content of Cu, Zn decreased.5,pH changes of soil layer of water made differences as the application of fertilizer varied. The layer of water was in the higher pH when applicating Urea, while Coated organic fertilizer application had a lower pH, nearly to none fertilizer comparion. The high water pH was closely related to nitrogen content of the water layer, the higher pH water was, the easier NH₃ volatilization losses speeded.