宜章县耕地质量等级与土壤养分特征分析
Characteristics of Cultivated Land Quality Grade and Soil Nutrients in Yizhang County

弄清宜章县耕地土壤肥力现状及其质量特征，为挖掘耕地生产潜力和保障粮食安全提供依据。本研究基于第三次全国国土调查，采用耕地土壤调查、土壤采集、分析测定、数学模型等方法，研究了宜章县耕地土壤有机质、pH、有效磷与速效钾等肥力特征，并按照《耕地质量等级》(GB/T 33469-2016)的技术路线进行了耕地质量评价。结果表明宜章县耕地土壤肥力处于中等水平，土壤有机质均值为36.7 g/kg，有效磷均值为20.6 mg/kg，速效钾均值为118 mg/kg，pH均值为6.29。耕地质量加权平均等级为4.91，高产耕地(一至三等地)面积9198.88 hm²，占耕地面积的31.16%；中产耕地(四级至六级级)面积为12,867.98 hm²，占耕地总面积的43.58%，低产耕地(七级至十级)面积为7461.26 hm²，占耕地总面积的25.26%。基于宜章县耕地质量等级与土壤肥力特征，应采取科学施肥、改善排水灌溉状况、治理耕地土壤酸化、保育高产耕地与提升及改良中低产耕地的手段，以提升耕地质量并提高粮食生产能力。
To clarify the present situation and quality characteristics of cultivated land soil fertility in Yizhang County, so as to provide the basis for exploring the potential of cultivated land production and en-suring food security. Based on the third national land resource survey, this study studied the fertil-ity characteristics of cultivated soil organic matter, pH, available phosphorus and available potas-sium in Yizhang County by using the methods of soil survey, soil collection, analysis and measure-ment, and mathematical model. The cultivated land quality was evaluated according to the tech-nical route of “Cultivated land quality grade” (GB/T 33469-2016). The results showed that the soil fertility of cultivated land in Yizhou County was in the medium level, with the mean of organic mat-ter being 36.7 g/kg, available phosphorus 20.6 mg/kg, available potassium 118 mg/kg and pH 6.29. The weighted average grade of cultivated land quality was 4.91. The area of high-yield cultivated land (Grade 1 to 3) was 9198.88 hm², accounting for 31.16% of the cultivated land area. The area of middle class cultivated land (Grade 4 to 6) is 12867.98 hm², accounting for 43.58% of the total area of cultivated land, and the area of low yield cultivated land (Grade 7 to 10) is 7461.26 hm², ac-counting for 25.26% of the total area of cultivated land. Based on the quality grade of cultivated land and the characteristics of soil fertility in Yizhang County, scientific fertilization, improvement of drainage and irrigation, control of soil acidification of cultivated land, conservation of high-yield cultivated land, promotion and improvement of middle-low yield cultivated land should be adopted to improve the quality of cultivated land and grain production capacity.