中国近期耕地资源与粮食综合生产能力的变化态势

Changes of Agriculture Resources and Grain Comprehensive Productive Capacity of China in Recent Years

该文在分析1996年～2003年我国耕地资源变化格局的基础上,探讨了耕地资源变化对粮食生产的影响,包括耕地面积、粮食播种面积、粮食总产量和粮食单产的年际变化率以及四者之间的相关关系。分析认为,我国耕地的流失呈加剧趋势;粮食播种面积和粮食总产呈下降趋势,且幅度较大;粮食单产变化不大。耕地面积年变化率和粮食播种面积年变化率之间具有一定的相关性;耕地面积年变化率和粮食总产量年变化率之间的相关性并不强;粮食播种面积变化率和粮食产量变化率之间相关性较强,两者的变化基本同步;粮食总产量变化率和粮食单产变化率之间相关性很强,变化趋势基本一致。最后分析了2003年粮食总产量和主要粮食作物产量下降的原因,认为造成总产量下降的主要原因是播种面积的减少,单位面积的生产能力基本未下降,而且粮食品种结构与粮食品质均有了明显改善;生态退耕尽管减少了粮食播种面积,但有助于提高耕地的总体质量,增强粮食综合生产能力;保护和提高单位面积的粮食综合生产能力是保障我国粮食安全的基本战略。

Food security has become one of strategic choices of China. The quantity, quality and circumstance of cultivated land resource are the most basic limiting factors influencing the food security. So, It is highly important to analysis the cultivated land resource change, which will offer the scientific basis for improving the grain productive conditions, then assure the increase of supply and demand of grain on the same speed. This paper analysis cultivated land resource change from 1996 to 2003 in China, which indicate that: 1)The main reasons of cultivated land decrease are the reuse farmland for forest and grassland, the agricultural structure readjustment and the changing of land use method from agriculture to industry or commerce; 2)The new cultivated land from reclamation is mainly infertile land, which accelerated the deterioration of its weak environment; 3)The productive capacity and environment of cultivated land resources have changed diversely, some improved but other degenerated. Based on this, this paper probes into the impacts of quantity change and quality status of cultivated land resource on grain production, and make out that the relativity between cultivated land area and grain planting area is high(R=0.7686), the relativity between cultivated land area and grain overall is low (R=0.3737), and the relativity between grain planting area and grain overall output is higher (R=0.8003). Moreover, the reasons of the decrease of the grain overall output and the main crops output in 2003 are emphasized, they are mainly the decreases of cultivated land area, bad weather, plant diseases and insect pests, the weakness of the service institution of agriculture technology. Based the above discussion, we can get the results that the grain comprehensive productive capacity of per area almost hasn't declined, and the decrease of grain planting area is the main reason leading to the decrease of grain overall output; The productive scope of high quality grain has become bigger and bigger, grain quality and the grain varieties structure have improved obviously; The reuse farmland for forest and grassland ostensibly causes the decrease of grain planting area, actually helps the improvement of the quality of cultivated land, which will reinforces grain comprehensive productive capacity of per area. Furthermore, it is argued that protecting and improving the grain comprehensive productive capacity of per area is the basic strategy to ensure food security.