Effects of alfalfa green manure on rice yield and soil fertility

A field experiment was carried out to determine the effects of alfalfa green manure and nitrogen fertilizer on rice yield, soil organic matter, soil nitrogen, soil available P and soil available K by planting alfalfa as green manure into winter fallow fields in the south region of China. The results of this study showed that the rice yield in the alfalfa manure treatment and alfalfa manure+nitrogen treatment increased by 48.2% and 72.1%, respectively. Alfalfa green manure significantly increased the contents of soil organic matter, total nitrogen, available P and available K, implying that Alfalfa green manure improved the physical and chemical properties of soil. The alfalfa+nitrogen treatment effectively improved the soil organic matter content and P and K activity, which promoted the rice to uptake more soil P and K, resulting in the increase of rice production. This study suggested that alfalfa was an effective green manure for improving rice soil quality, increasing nitrogen efficiency, and increasing rice yield, and would be a very good green manure resource for improving farm land quality in the south region of china.