Changes in the efficiency of fertiliser use in China

Results of three nationwide fertiliser efficiency studies in recent history in China are reviewed. The results indicate that after a long history using organic recycling to maintain soil fertility in China, nitrogen (N) became the first yield-limiting nutrient in the first national fertiliser efficiency study in 1935-1940. With N fertilisation being used, phosphorus (P) and potassium (K) deficiencies were gradually revealed and developed in the following national fertiliser efficiency studies in 1958-1962 and 1981-1983. Research conducted through the International Plant Nutrition (IPNI) cooperative network in China in 2000-2006 indicates that agronomic efficiencies of N fertiliser (yield increase per kilogram from the application of 1 kg N) for rice, wheat and maize are 11.7 kg, 10.8 kg and 12.2 kg grain per kilogram of N, respectively, while crop recovery efficiency of N (percentage of N taken up by plant in total N applied) with rice, wheat and maize were 24.8%, 35.7% and 30.5%, respectively. Both agronomic efficiency and crop recovery efficiency of N are significantly lower than the average N use efficiency reported in international literature for other countries. Current agronomic efficiency of P and K are also discussed. Measures to improve fertiliser use in China are discussed.