华北小麦玉米轮作区耕地地力等级划分及特征

华北地区在我国粮食生产中占有举足轻重的地位,小麦玉米轮作是该区域主要种植制度。本文选取华北小麦玉米轮作区为研究区域,从农业部县域耕地地力调查与评价数据库中甄别遴选了23 862个评价样点,采用土壤图、土地利用现状图和行政区划图组合叠置确定了17 945个评价单元,选取了降水量、积温、地貌类型、耕层厚度、耕地质地、有机质、有效磷、速效钾、有效锌、盐渍化程度、灌溉能力等11个指标,运用特尔斐法、模糊评价、层次分析等方法对耕地地力进行了评价。结果表明:华北小麦玉米轮作区1~6级耕地面积分别占总耕地面积的11.29%、19.30%、28.06%、21.57%、11.99%和7.80%。在定量分级的基础上,将本次评价数据与第二次土壤普查数据进行深入对比,结果发现:该区域耕地地力总体水平上升,主要表现为土壤有机质、有效磷、速效钾的含量明显上升。评价结果将为华北地区地力培肥与土壤改良、科学布局作物生产、提升耕地生产能力等提供基础信息和科学依据。

Characteristics and Gradations of Cultivated Land Fertility for Winter Wheat-Summer Maize Rotation System in North China

North China area is playing a significant role in grain production in China. Winter wheat-summer maize rotation is a major cropping system in this region. Based on the database of county cultivated land survey of soil fertility in Ministry of Agriculture of the People's Republic of China, total 23 862 samples were selected, 17 945 evaluation units were taken from the superposition of soil map, landuse map and administrative map. 11 evaluation indicators, including precipitation, accumulated temperature, top layer thickness, texture, organic matter, available P, available K, available Zn, salinity and irrigation capacity, were used to evaluate the gradation of the cultivated land fertility. The results showed that the fertility grades from first to sixth of the cultivated land for winter wheat-summer maize rotation system in North China accounted for 11.29%, 19.30%, 28.06%, 21.57%, 11.99% and 7.80%, respectively, and the overall cultivated land fertility upgraded in comparison with the second soil survey. The concentrations of soil organic matter, available P, available K were increasing significantly. In conclusion, this study will provide some basic information and scientific insights into specifically practical fertilization and soil improvement, scientific layout of crop production and adjustment of agricultural structure to promote cultivated land production capacity.