中国主要粮食作物化肥施用量与效率变化分析

2004年至今,在国家支农政策的推动下,农业种植结构大幅度调整,粮食产量连续增加,而且启动了全国测土配方施肥项目。采用2008年的农户调研数据与2001年进行对比,揭示了我国粮食生产体系中化肥效率的变化。结果表明,过去7年中小麦和玉米的单位面积化肥用量分别增加5.4%和29.0%,而水稻减少4.3%。全国粮食作物化肥消费总量增加1.3×106t,但占全国化肥消费总量的比重从68%下降到50%。用PFP(粮食产量除以化肥用量)表征化肥效率,发现三大粮食作物的化肥效率大小排列顺序为水稻小麦玉米;7年中小麦和水稻的化肥偏生产力分别从10.6 kg/kg增加到11.9 kg/kg,13.9 kg/kg增加到15.7 kg/kg,玉米的化肥偏生产力从13.8 kg/kg下降到11.5kg/kg。我国农业种植结构调整对化肥施用量影响较大。粮食作物向优势主产区集中以及机械和管理措施的改善有利于进一步提高粮食作物化肥效率,但经济作物播种面积仍在大幅增加,这将对全国化肥效率变化带来变数。

Chemical fertilizer use and efficiency change of main grain crops in China

Since 2004, China has increased the grain production significantly due to the impetus of strong policies, including the soil testing and fertilizer recommendation. This paper analysis the changes of the fertilizer efficiency in Chinas grain production systems by comparing the farmers practice in 2008 and 2001 respectively. The results show that，chemical fertilizer application rate increased by 5.4% and 29.0% in wheat and maize system in the past seven years, and decreased by 4.3% in rice. Total fertilizer consumption increased 1.3×10⁶t on grain crops, but its proportion decreased from 68% to 50% in the total chemical fertilizer consumption of whole China. PFP(grain yield divided by the amount of fertilizer)was used to present the fertilizer use efficiency. We find that the PFP of rice are higher than wheat, and then maize. The PFP of wheat and rice increased from 10.6 kg/kg to 11.9 kg/kg and from 13.9 kg/kg to 15.7 kg/kg, and that of maize decreased from 13.8 kg/kg to 11.5 kg/kg respectively in last 7 years. The change of planting structure has a strong impact on the fertilizer application. The concentration of the main planting area of cereal crops is good to improve the fertilizer efficiency of cereal crops, but the increasing of the area of economic crops makes the fertilizer efficiency may continue to decrease in China.