化肥施用量对中国粮食产量的影响分析

化肥对粮食生产的影响是粮食经济研究的重要议题,文章基于1994—2018年中国粮食主产区玉米、小麦、水稻三种主粮作物化肥施用量和粮食产量的面板数据,构建分位数回归模型,分析化肥施用量对粮食产量的影响。研究表明,随着化肥施用量的持续增加,对粮食作物的单产水平具有显著的关联效应,且呈现明显的阶段性增长特征。1997年以前,化肥施用量和单位面积粮食产量浮动程度趋于水平。1998—2004年,化肥施用量呈现大幅度跳跃趋势,但其总体产量始终维持在5 000 kg/hm~2以上。2004—2015年,化肥施用量和粮食单产都呈现出逐步递增的发展趋势。2016年后,化肥施用量和粮食单产出现小幅度增长再到小幅度回落的趋势。此外,在0.1～0.9分位点上,随着分位点的升高,玉米的化肥施用量对其单产存在正向作用,但已呈现边际效用递减特征,反观小麦、水稻的化肥施用量对其单产的促进作用逐渐减弱。为此,在坚持化肥施用零增长的前提下,需注重科学施肥、结合有机肥混合施用以提高化肥利用率,便于在保障粮食安全与促进农业可持续发展之间达成平衡。

Analysis of the effect of chemical fertilizer application on grain yield in China

The impact of chemical fertilizer on grain production is an important issue in the study of the grain economy. Based on the panel data of the amount of chemical fertilizer and the grain yield of corn, wheat, and rice in Chinas major grain producing areas from 1994 to 2018, this paper designed a quantile regression model to analyze the impact of chemical fertilizer application on the grain yield. The Research showed that with the continuous increase in the amount of chemical fertilizer, the grain yield per unit area had a significant correlation effect with it, and had the obvious characteristics of periodic growth. Before 1997, the fluctuation degree of amount of chemical fertilizer used and the grain yield per unit area tended to the same level. From 1998 to 2004, the amount of chemical fertilizer used showed a large jump in the trend, but the total yield remained above 5 000 kg/hm2. From 2004 to 2015, the amount of chemical fertilizer used and grain production showed a gradually increasing development trend. After 2016, the amount of chemical fertilizer used and the grain yield showed a small increase and then a small decline. In addition, at the 0.1-0.9 quantile, with the increase of the quantile, the fertilizer application rate had a positive effect on the yield per unit area of maize, but the marginal utility was decreasing. On the other hand, the effect of fertilizer application on yield of wheat and rice gradually weakened. On the premise of insisting on zero growth of chemical fertilizer application, we should pay attention to scientific fertilization and combined application of organic fertilizer to improve the utilization rate of chemical fertilizer, so as to achieve a balance between ensuring food security and promoting sustainable development of agriculture.