Effects Of Stylosanthes Spp. Green Manure Application Mixed With Phosphate Fertilizer On The Movement And Transformation Of Inorganic Nitrogen And Phosphorus In Acidic Soil Manure/Fertilizer Microsites

Most of the soils in the South of China are acidic soil. The common problems include low organic matter and mineral nutrient content, aluminum toxicity, low acidity, etc. Application of organic manure is an effective way to solve these problems. Phosphate fertilizer is often applied together with green manure due to similar property of nutrients supply. After fertilization, the fertilizer/manure microsites will be formed close to the fertilizer/manure. Changes of inorganic nitrogen and phosphorus in the special soil environment are obviously different from the mass soil. Research on the soil nutrient movements and transformation in this part of soil has important value in the study of plant nutrition and soil science in fertilizer/manure microsites. The soil column section method was used to research the movement and transformation of inorganic nitrogen and phosphorus in fertilizer/manure microsites of acid soil after the application of green manure mixed with phosphate fertilizer. The main results are as follows:1. Application of phosphate fertilizer (MCP) did not significantly increase the contents of ammonium nitrogen and nitrate nitrogen and their migration distances in soil fertilizer/manure microsites. Green manure application or mixed with phosphate fertilizer significantly increased the contents and migration distances of ammonium nitrogen and nitrate nitrogen in soil fertilizer/manure microsites. Green manure Application or mixed with phosphate fertilizer increased the content and movement distance of ammonium nitrogen in soil fertilizer/manure microsites after14and28days, and the high quantity of green manure application(GMH) or mixed with phosphate fertilizer (GMH+MCP) significantly increased the content of ammonium nitrogen at the28th day, but GMH more than GMH+MCP, and the movement distance was farther. The content of nitrate nitrogen in low amount of green manure application (GML) was apparently improved, and the content of nitrate nitrogen of low amount of green manure application mixed phosphate fertilizer (GML+MCP) was lower than that of GML treatment.2. Application of phosphate fertilizer, green manure and green manure mixed phosphate fertilizer increased the content and movement distance of available phosphorus, Al-P, Fe-P, Ca-P, O-P in soil fertilizer/manure microsites, but there were differences between different treatments and between different times. The manure/fertilizer treatments promoted the movement of available phosphorus, Al-P, Fe-P, Ca-P and O-P differently in fertilizer microsites at the14th days. Compared with the data on the14th day after fertilization, MCP treatment increased the movement of available phosphorus and O-P more than the other treatments, GMH+MCP treatment increased Al-P、Fe-P and Ca-P more than the other treatments at the28th days. MCP significantly increased the content of available phosphorus and GMH+MCP significantly increased the content of Al-P, Fe-P, Ca-P and O-P in soil fertilizer/manure microsites after14and28days, and the increases after28days were higher than that after14days. In addition, the increased of Al-P and Fe-P by GMH+MCP is higher than the increased of Ca-P and O-P, the available phosphorus is supplied by phosphate fertilizer mainly.3. The green manure decomposed rapidly in the first14days after application.14days later, green manure decomposed slowly. The decomposition rate of green manure application mixed phosphate fertilizer was significantly lower than that of green manure application in the first14days after fertilization. The role that phosphate fertilizer inhibited the decomposition rate of green manure disappeared at the28th day, the decomposition rate of green manure application mixed with phosphate fertilizer increased rapidly. And the decomposition rates of high amount of green manure application were lower than that of low amount of green manure application in the first14days.4. After application of green manure, the soil pH near fertilizer microsites increased. Application of green manure or mixed with phosphate fertilizer increased the soil pH near fertilizer microsites after14and28days. On the14th day, the soil pH of high quantity of green manure application was the highest at6.67, and that of MCP was the lowest at5.28. On the28th day, the soil pH of high amount of green manure application mixed phosphate fertilizer was the highest at7.29, and that of MCP was the lowest at5.29.