基于可改良限制因子的耕地质量等别提升潜力研究

分析不同尺度耕地质量等别提升理论潜力和实际潜力空间分布特征,为加强耕地保护和提升耕地质量提供依据。该文以辽宁省大石桥市为研究区,基于大石桥市农用地分等结果,筛选土地整治工程可改良限制因子,构建指数提升潜力模型测算研究区耕地质量自然等、利用等和经济等指数的理论潜力与实际潜力。运用面积加权法和局部空间自相关法,揭示研究区乡镇、村级和地块不同尺度的耕地质量等别提升潜力的空间分布特征。结果表明:1)各乡镇耕地质量等别提升潜力空间差异明显,呈现东高西低,依次递减;2)各行政村耕地质量等别提升潜力东部属于正相关类型(高-高型)且集中连片,中部正相关类型(低-低型)面积较小且零星分布,西部为随机分布;3)东中部地块耕地质量等别提升潜力较大,东部坡耕地宜实施土地平整工程,中部耕地宜实施灌溉与排水工程。研究结果可为区域规划土地整治重点工程和划定耕地保护分区提供理论与技术支持。

Potential of cultivated land quality grade improving promoted by improvable limiting factors

It is important to calculate the theoretical and realistic potential of cultivated land quality and protect cultivated land. Land consolidation is an effective way to promote quality of cultivated land by improving limiting factors. To definite the role of land consolidation in arable land quality grade, choosing some agricultural land grading factors which land consolidation can improve in time and positively is principle. Setting the theoretical top and realistic top score of different crop classification factors as targets respectively, calculating theoretical and realistic potential of cultivated land by the potential index model of the agriculture land natural quality grade is basic. Making realistic potential of cultivated land as the aim of land consolidation project would be more scientific and objective. The utilized grades could be calculated based on the natural grade by ability coefficient of land use. The economic grades could be calculated based on the utilized grades by land economic coefficient. According to the distribution of theoretical and realistic potential of natural, utilized and economic grades from townships, villages and plots, land projection project can be planned, designed and arranged in advance. The first step is to determine the improvable limiting indexes of agricultural land classification. Dashiqiao county of Liaoning province was taken as the study area based on the complement of arable grade in 2012. The study area has arable land and slope arable land which have respective improvable limiting indexes. Arable land has thickness of soil layer, terrain slop, irrigation guarantee ratio and degree of surface rock outcrop. While slope arable land has irrigation guarantee ratio, degree of salinity, drainage conditions and irrigation water source. Afterwards, we calculated the improvable theoretical and realistic degree of each selected indexes by land consolidation project based on plot respectively. Then utilized and economic grades would be calculated later. Finally with the area weighing method to summarize the results into villages and townships, we analyzed the character of theoretical and realistic potential of arable land on different scales. In villages scale we used local spatial auto-correlation method specially. The results showed that 1) Under the township scale, the theoretical and realistic potential of cultivated land quality improvement was obvious, showing high in the east and low in the west, decreasing in turn; 2) At the village level, the potential of cultivated land quality in eastern was High-High type and concentrated, in the middle was Low-Low type and distributed separately with small area, and in the west was random distribution; 3) Under the plot scale, potential of arable land quality had great promotion in eastern and middle of research area. Thickness of soil layer and terrain slope of eastern slope farmland should be improved by implementing land leveling project. Degree of salinity and drainage condition of middle farmland could be promoted by irrigation and drainage works. In conclusion, theoretical and realistic potential of arable land of research area have significant distinctions on different scales obviously, which provides the basis and technological support for developing a key cultivated land consolidation project and demarcating the boundaries of protection of cultivated land.