[Nutrient and water cycling in red soils with different planting system and their management].

Based on the data of long term located experiment, this paper studied the characteristics of nutrient and water cycling and balance and of energy flow in upland red soils with different planting system. The results showed that in red soil areas, the rainfall from March to June accounted for 60% of the whole year, which induced frequent seasonal drought and severe water and soil loss. The application of N, P and K on upland red soil was overabundant and unbalanced, which induced a reduced ratio of input and output. Optimized planting mode could increase the water and light utilization efficiency, decrease the frequency and degree of occurred drought, and increase the nutrient recycling rate. The main measures for rationally developing and utilizing red soil should be establishing compound agro-ecosystem model of planting and feeding, saving irrigation water, increasing mulch, cover-cultivating crops and forests, increasing the proportion of organic fertilizer, realizing rational and balanced fertilization, further optimizing planting structure, regulating energy input structure, and adopting multilevel-technologies of food chain utilization.