The Effect Of Long-term Fertilizer Application On Improvement Of Parent Material In Red Soil

Red soil is an important soil type in South China, but the acidity is strong and there is lower organic matter and nutrient contents in red soil. Application of fertilizer is one of the most important practices for red soil, and combined use of organic and inorganic fertilizers can improve the fertility of red soil. The utilization mode can also afact the fertility of red soil. According to the present condition of soil fertility and the agricultural development in red soil area, the effect of long-term fertilizer application on parent material improvement in red soil was studied.This paper was on the basis of many years data in Hengyang red soil station of Chinese Academy of Agricultural Sciences. The effect of long-term fertilizer application on red soil character, crop growing, P composition, P absorption and desorption in red soil was studied, and the type, transformation and available of organic sulfur and inorganic sulfur in red soil was elaborated. The result showed as follows:1.Organic fertilizer and organic-chemical fertilizer application was an efficient method to increase the soil organic matter. Long-term fertilizer application and cultivation in red soil could accelerate the recycling of organic matter, and the main of the increased organic matter in red soil was the new formative organic matter.2. The amount of available P in red soil could be rapidly increased by applying P fertilizer , it's the best method to improve the P condition of the red soil. Compared with the N treatment, recycling coefficient of P had been increased by 80.1% under the organic fertilizer(NPKM) treatment. The capability of supplying P in red soil could be increased under the treatment of long-term organic fertilizer application. Acidification of red soil could be prevented and the amount of available P in red soil could be increased.3. Productivity of red soil decreased gradually if there was a short of organic fertilizer application in red soil area for a long-term. The conclusion was that, the productivity of red soil could be increased by organic fertilizer application.4.There was a slight short of sulfur in red soil under the treatment of no-application P fertilizer. Compared with that of no-application P fertilizer treatment, available sulfur in red soil increased significantly under the treatment of P fertilizer application. The amount of available sulfur also increased in red soil under the treatment of organic fertilizer. But the effect was inferior, compared with the treatment of chemical P fertilizer. The amount of available sulfur in red soil could be kept in high level if there was P fertilizer application for long-term in the subtropics red soil area.