我国粮食生产格局演变及增产贡献研究

[目的]通过测算各省区粮食增产潜力和各省区可比耕地资源量,揭示不同阶段我国及各省区粮食生产及增产的特点及原因,揭示我国今后粮食增产的方向。[方法]结合生产力相对指数与耕地面积分析我国各省耕地资源量,测算了复种指数和单产对我国及各省区粮食增产的贡献率,测算了我国各省区粮食增产的潜力。[结果]我国各省区人均粮食产量差异明显扩大。1985~1998年间,粮食单产对粮食产量增加的贡献率为85.35%;1998~2003年间,我国粮食总产量下降,播种面积减少是主要原因;2003~2013年间,单产增加依然是增产主因,但播种面积增加的贡献明显提高。1985年相对生产力耕地资源的省际差异明显大于2013年,据该文估算,我国可增产粮食22.9%~43%,复种指数对于粮食增产的潜力十分可观。[结论]近30年来,我国粮食生产格局是"南降北升",播种面积差异是粮食生产省际差异的主因。1985~2013年间,粮食播种面积仅占农作物增播面积的15.48%。大多省区耕地复种指数提升空间较大,但多数省区现实的复种指数却在下降,原因是农业生产比较利益低下。进一步提高单产的边际约束效应明显凸显,提高复种指数应该是我国提高粮食产量的方向。

SPATIAL-TEMPORAL EVOLUTION OF CHINESE GRAIN PRODUCTION PATTERN AND ARABLE LAND PRODUCTION CAPACITY

The purpose of this study is to measure the grain production potential and the comparative cultivated land resources, and reveal the grain production reason of different stages in China.Based on the perspective of comparative productivity, this paper studied the spatial-temporal pattern of grain production in China, measured the contribution of multiple crop index and per unit area yield of grain in different periods, evaluated the comparable cultivated land resources, and explored the development direction of China's grain production.The results showed that: over the past 20 years, the grain production proportion in the traditional major grain-producing provinces declined obviously with a pattern of "south low north high", planting area was the main reason for provincial differences of grain production.The provinces with the relative productivity less than 1 mainly distributed in these regions where the hydrothermal conditions were poor.The actual multiple crop index decreased obviously.From 1985 to 2013, the increase of per unit area yield of grain contributed greatly to the total grain output increase, but only 22.2% in 2014.The marginal constraint effect for further improving of per unit area yield was obvious.Therefore, to improve multiple crop index may be the direction of improving grain production of China.