基于农用地分等的耕地质量主导限制型研究

耕地自身存在限制因素是阻碍耕地质量提升的重要原因之一,确定耕地质量主导限制型对耕地质量建设与管理具有深远意义。文章依托耕地质量等级监测试点项目,以湖北省公安县为研究区,结合2010年农用地分等补充完善成果和耕地质量等级监测成果,确定了影响耕地质量的9种限制型:排水限制、质地限制、水分限制、障碍层次限制、污染限制、酸碱度限制、有机质限制、灌溉限制以及剖面构型限制。应用自然等提等潜力指数模型,以全局可比的无量纲形式反映出限制型的制约程度和自然等别提升潜力,从而计算出耕地质量限制型谱序,对确定耕地质量主导限制型方法进行了研究。结果表明:公安县存在12种耕地质量主导限制型组合类型,其中2~5等地以酸碱度限制、酸碱度-水分限制和水分限制为主,6~7等地以酸碱度限制、灌溉限制和排水限制为主。依据确定的耕地自然等质量主导限制型,可以针对不同等别的耕地采取对应的质量提升措施。

DOMINANT LIMITING TYPES OF THE QUALITY OF CULTIVATED LANDBASED ON AGRICULTURAL LAND GRADATION

The existence of dominant limiting types of cultivated land quality is one of the important factors hindering the improvement of cultivated land quality. Therefore, to find out the dominant limiting types has great significance for the construction and management of cultivated land quality. Taking Gongan County in Hubei Province as the study area, based on the cultivated land quality monitoring and the achievement of arable land grade in 2010, this paper firstly analyzed the limiting types in both domestic and foreign quality of the existing cultivated land evaluation system, and then determined the limiting types which impacted the cultivated land natural quality in China, i.e., drainage, soil texture, moisture, edaphic hindrance gradation, contamination, pH, organic matter, irrigation guarantee rate and structure profile, using the meta-analysis method. In addition, it studied the dominant type limit method for determining the cultivated land quality using the potential index model.The global comparable dimensionless form can reflect the limit degree of restriction and natural potential, so as to calculate the limit spectrum sequence of the arable land quality.Results showed that there were 12 combined dominant limiting types of cultivated land quality in Gongan County, which were pH- moisture, moisture, pH, edaphic hindrance gradation, drainage, structure profile, contamination, irrigation guarantee rate, structure profile-pH- moisture, organic matter, structure profile-pH and pH- edaphic hindrance gradation. The limitations of cultivated land quality in grade 2-5 were mainly pH, pH-moisture and moisture. Therefore, the construction of farmland water conservancy facilities should be strengthened to improve irrigation and drainage conditions and reduce the ground water level. Simultaneously, soil amendment should be agented to ameliorate the pH of soil. As for the grade 6-7 of the lands, limitations were pH, irrigation guarantee rate and drainage. In response, water conservancy facilities and drainage engineering should be strengthened in order to improve construction of farmland water conservancy. Meanwhile, soil amendment should be agented. Results can scientifically reflect the quality of cultivated land and provide an important basis for improving the quality of cultivated land.