Highly Efficient Nutrient Management Strategy for Modern Rice Planting in China

As a major source of nutritional calories, over 60% population of China eats rice. With the reduction in planting area and the increase in population, food security and safety has became a prominent issue in the country. In rice production, the issues of maintaining the delicate balance between yield and quality, yield and efficiency, yield and ecological environment are becoming important. Therefore, this study is being conducted on the technology of efficient nutrient management for improving fertilizer use efficiency in China. This project includes the main rice production provinces (Jiangxi, Hubei, Hunan, Guangxi, Fujian, Yunnan, Heilongjiang, Zhejiang) in the country. All the provinces involved in the project collect data from rice field experiments following a uniform experimental design.

Both nutrient use efficiency and agronomic efficiency of commercial fertilizer application have decreased with an increase in fertilization rates in the last decade. In Jiangxi, the contribution of fertilization and fertilizer N, P and K to rice yield increases were 41, 32, 10, and 11%, respectively. Researchers recommend that 40% of N and K fertilizers should be basally applied in early rice, and 50% of N and K fertilizers should be basally applied in late rice. In Fujian, the contributions of fertilizer N, P and K to rice yield increases were 40, 15 and 39%, respectively. The recommended N fertilization rate for early and late rice was 162 kg N/ha with a N:P₂O₅:K₂O ratio of 1:0.4:0.65; while for middle rice, it was 206 kg N/ha with a ratio of 1:0.4:0.8. The most appropriate N fertilization timing during the rice-growing season at the base:tillering:panicle:granular stages was 30:20:30:20 for early rice and 40:20:20:20 for late rice. The basal:topdressing proportion of K fertilizer was 50:50. In Hubei, rice production is mainly middle rice with an average yield of 7.9 t/ha and average fertilization rate of 185 kg N/ha with a ratio of N:P₂O₅:K₂O as 1:0.35:0.30. The recommended fertilization rates for rice in Hubei were 165 to 210 kg N/ha, 60 to 90 kg P₂O₅/ha and 75 to 120 kg K₂O/ha. The optimum N fertilization ratio during the rice growing season was determined at base:tillering:panicle stages was 40:30:30, and the basal:topdressing proportion of K fertilizer was 50:50. Results from other provinces showed a similar pattern.