Strategies And Potential To Improve On-farm Cereal Crops Yield And Fertilizer Use Efficiency In China

Demand for both food and energy is quickly risig and will continue to rise with increases in population, development of economy and process of urbanization in China.Improving cereal crop yield has become an essential approach to guarantee the food safety, as the cultivated land resources are limited. Fertilizer plans an important role in cereal crop production. But excessive or unreasonable of fertilizer application, will lead to soil nutrient imbalance, low fertilizer use efficiency, makes a lot of nutrients into environment, causing the waste of resources and energy, influence the air and water quality, resulted in environmental pollution, harmful to human health. Therefore, how to realize the high yield and high fertilizer use efficiency in large area is particularly important. For this reason, the indexes, such as yield gap and agronomic efficiency (AE), were calculated based on the experimental data from National Program of Soil Testing and Fertilizer Recommendation of China and the data from farmer investigation, and the strategies and potential to impove on-farm cereal crops yield and AE were analyzed in different main producing regions of wheat, mazie and rice in China. To be aware of further improve cereal crop yield, fertilizer use efficiency, and to guide and realize reasonable allocation and employ of fertilizer in China. The main research results were summarized as follows:1 There are great potential for closing yield gaps in cereal corps production of China and potential varied crops and regions. The average farmers’yield of wheat was 95% of the average yield in experimental plots, 83% of the average yield of high-yield farmers, and 56% of the yield record. In different main producing regions, the potential for closing yield gaps in wheat production in Northwest China (NWC) was largest. The average farmers’yield of maize was 89% of the average yield in experimental plots, 83% of the average yield of high-yield farmers, and 46% of the yield record. In different main producing regions, the potential for closing yield gaps in maize production in Southwest China (SWC) was largest. The average farmers’yield of rice was 94% of the average yield in experimental plots, 85% of the average yield of high-yield farmers, and 60% of the yield record. In different main producing regions, the potential for closing yield gaps in rice production in Northeast China (NEC) was least. Comparison of the potential for closing yield gaps among cereal crops, the greatest was maize, medium for wheat, and the lowest for rice.2 The current AE of wheat, maize and rice were lower compared with endurable AE potential and realizable AE potential in China. There are great potential to improve AE of wheat, maize and rice. Agronomic efficiency of applied N (AEN) was 62% of endurable AEN potential for wheat, 43% of endurable AEN potential for maize, and 44% of endurable AEN potential for rice. Agronomic efficiency of applied P2O5 (AEP) was 42% of endurable AEP potential for wheat, 51% of endurable AEP potential for maize, and 33% of endurable AEP potential for rice. Agronomic efficiency of applied K2O (AEK) was 81% of endurable AEK potential for wheat, 100% of endurable AEK potential for maize, and 51% of endurable AEK potential for rice. The potential to improve AEN and AEP were greater than AEK.The wheat production in NWC, maize and rice productions in SWC had better potential to improving AEN; the wheat production in NWC, maize production in SWC, and rice production in NEC had better potential to improving AEP; the wheat production in Huanghuaihai Plain, early rice and late rice productions in Southern had better potential to improving AEK.3 To meet the demands for wheat, maize and rice in China for the year 2015 and meanwhile achieve endurable AE potential, in addition to maize need to increase the potash, there are a potential of saving N, P2O5 and K2O fertilization rates. The saving N, P2O5 and K2O fertilization rates in total are estimated to be 1.37~2.75, 0~1.21 and 0~0.75 million ton, respectively. Furthermore, the potentials to improve AEN and save nitrogen fertilizer are largest, followed by P2O5 and then by K2O. In order to reach the yield level of high-yield farmers and endurable AE potential, the key fertilizer managing strategies are”Decrease N, Increase P2O5 and K2O”for wheat,”Decrease N, Maintain P2O5, and Increase K2O”for maize, and“Maintain N and P2O5, Increase K2O”for rice. In Conclusion, the effective strategies to improve on-farm cereal crops yield and fertilizer use efficiency that is to increase cereal crops yield through integrated measures while fertilizer application rate is kept stable or decreased.