Study on high efficiency nutrient use and regulation of soil nutrient dynamics for high yield rice

Rice planting plays a crucial role in food production of China. Area of rice growing is approximately 1/4 of the total area of grain crops, while rice yield approached to 1/2 of total grain crop yield. Hunan is the largest province for rice production in the country. The Agriculture Ministry of China started the plan of “Super Hybrid Rice Breeding in China” in 1996, and new breeding aim of super hybrid rice would be increased by 15-30% over original hybrid rice combination at the end of 2005. In 2006, the planting area of super hybrid rice have reached 4 million ha with the average yield 13.5t/ha. High yielding conventional rice or super high yielding hybrid rice have their own nutrient characteristics. But in recent years, fertilizer rates for high yielding conventional rice and super high yielding hybrid rice were still calculated based on the nutrient requirement for conventional rice in 1990s. Thus it is very essential to research the nutrient requirement with high yielding conventional rice and super high yielding hybrid rice.