耕地变化对粮食生产能力的影响评价——以吉林中西部地区为例

在目前我国粮食供需相对紧张,部分耕地非农化利用的趋势日渐明显,政府粮食安全目标与农户利益之间的矛盾尚未真正解决,农产品市场日趋国际化以及国内粮食生产机遇与挑战并存的背景下,分析粮食主产区耕地资源变化格局与态势,研究其耕地资源变化对粮食生产能力的影响,具有重要的现实意义。本文利用GIS空间分析技术,着重从空间分布角度,通过研究两个不同时期区域耕地数量变化及引起的耕地质量空间分布变化,探讨区域耕地数量与质量变化对粮食生产能力的综合影响,并以吉林省中西部地区为例进行了实证研究。结果表明:①吉林中西部地区耕地数量净增加了0.82×104hm2;②减少的耕地中,三等地减少数量最多,一等地减少量最少;增加的耕地中,五等地增加数量最多,一等地增加数量最少;③吉林省中西部地区粮食总产净增加了0.52×104t。其中耕地减少使本地区粮食总产减少了39.09×104t,二等地和三等地的减少对粮食总产有较为突出的影响,分别占粮食总产减少总量的28.36%和44.82%。同时增加的耕地中,二等地的增加对粮食总产增加起了相当重要的作用,占本区粮食总产增加量的44.53%;④要实现耕地总量动态平衡必须保证耕地数量与质量的双重平衡。

Assessing the Impact of Cultivated Land Change on Grain Productive Capacity: A Case Study in the Central and Western Regions of Jilin Province

The current situation of grain supply and demand in our country is still tense, and the trend of cultivated land converting to non-agricultural use will get more obvious. The conflicts between the goal of local government's grain safety and farmers' interests have not been thoroughly solved. Furthermore, internationalization of domestic grain-production is progressing and opportunity and challenge of market for agricultural products coexist recently. Under the above-mentioned background, analysis of the changing patterns of cultivated land in main grain production areas and assessment of the impact of this change imposed on grain productivity is of great significance. This paper aims to explore the systematic approach to assess the impact of regional cultivated land change on grain productive capacity, by analyzing the spatial distribution of change of cultivated land quality caused by change of cultivated land quantity through GIS technology. Central and west regions of Jilin Province were selected as study area, this paper analyzed the impact of cultivated land change on its grain production capacity within this region. The result shows: 1)The quantity of cultivated land has increased by 8 200 hectares; 2)Through dividing cultivated land quality into fifth grades and analyzing the spatial distribution of change amount of each graded cultivated land, detailed information about the cultivated land quality has been obtained. the third grade cultivated land reduced plentifully among these decreased cultivated land, while the first-grade cultivated land reduced little at the same time; On the other hand, the fifth-grade cultivated land increased plentifully among the increased cultivated land and the first-grade cultivated land increased little simultaneously; 3)By analyzing the change pattern of grain yield in study area in combination data of change amount with data of grain yield per hectare within each graded cultivated land; it has been found that the grain production has only increased 0.52×10⁴t. Decreased amount of grain production caused by reduction of cultivated land was 39.09×10⁴t. And decreased amount of second-grade and third-grade cultivated land accounts for 28.36% and 44.82% respectively of the total decreased amount of grain production. At the same time, the increased amount of the second-grade cultivated land played quite an important role in grain production, accounting for 44.53% of the total increased amount of grain production; 4)To obtain a dynamic equilibrium of cultivated land general quantity in this area, the dual balances of the quantity and quality of cultivated land should be guaranteed simultaneously.