黄河支流陕西段渭河流域沿岸农业土壤肥力综合评价

Comprehensive evaluation of agricultural soil fertility along the Weihe River Basin in Shaanxi Province,a tributary of the Yellow River

农业土壤肥力综合评价是黄河支流陕西段渭河流域生态保护和农业可持续发展的重要环节。该文以黄河支流陕西段渭河流域沿岸农业土壤为研究区域,采集陕西段渭河流域沿岸地区13个代表性地点的农业土壤样品,测定了土壤pH、电导率、有机质、全钾、速效钾、全磷、有效磷、全氮共8个理化肥力指标,以及脲酶、蔗糖酶、过氧化氢酶3个生物肥力指标。利用主成分分析法和内梅罗指数法,计算出该地区土壤肥力综合指数,二者相互验证,获得该地区土壤肥力质量状况。分析测试结果表明:(1)该地区土壤pH普遍较高,均值为7.99,呈弱碱性;有机质含量均值为17.295 g/kg;全钾、全磷和全氮均值为6.17 g/kg、1.06 g/kg和1.27 g/kg;速效钾和有效磷的含量均值为133.46 mg/kg、16.02 mg/kg。(2)对陕西段渭河土壤整体综合肥力评价的结果,主成分分析法的平均综合肥力得分为-0.0015,内梅罗指数法的平均综合肥力得分为1.342。依据主成分分析法和内梅罗指数法对土壤肥力评价的标准,表明陕西段渭河流域沿岸农业土壤综合肥力为中等水平,土壤中养分含量适中,能满足一般农作物的生长需求,适宜作为普通农田的种植基地。(3)肥力影响因素主要为干旱的气候和所处地理位置,人为因素次之。研究结果可促进渭河流域农业土壤资源利用,对于保障陕西省粮食安全、经济发展和生态建设具有重要意义。

The comprehensive evaluation of agricultural soil fertility is an important link for ecological protection and sustainable agricultural development in the Weihe River Basin of the Shaanxi section of the Yellow River tributary. In this study, the Weihe River Basin of Shaanxi Province is taken as an example, as the research area. Agricultural soil samples are collected from 13 representative locations along the Weihe River Basin in Shaanxi Province. Eight physical and chemical fertility indicators are measured, including soil pH, electrical conductivity, organic matter, total potassium, available potassium, total phosphorus, available phosphorus, and total nitrogen, as well as three biological fertility indicators, namely urease, sucrase and catalase.Using principal component analysis(PCA) and Nemerow index method(Nemerow), a composite index of soil fertility in the area is calculated and the two are validated against each other to arrive at a qualitative status of soil fertility in the area.The analysis and testing results indicate that:(1) The soil pH in this area is generally high, with a mean value of 7.99 and weak alkalinity. The mean content of organic matter is 17.295 g/kg, while the mean contents of total potassium, total phosphorus, and total nitrogen are 6.17 g/kg, 1.06 g/kg, and 1.27 g/kg, respectively. The mean contents of available potassium and available phosphorus are 133.46 mg/kg and 16.02 mg/kg, respectively.(2) The results of comprehensive fertility assessment of Weihe River soil in Shaanxi Province indicate that the average fertility score by PCA is-0.001 5, while the average comprehensive fertility score using Nemerow index method is 1.342. Based on the criteria for soil fertility evaluation using principal component analysis and Nemerow index method, it shows that the agricultural soil in the Weihe River Basin in Shaanxi has a moderate level of comprehensive fertility, with moderate nutrient content in the soil that can meet the growth requirements of general crops, making it suitable as a planting base for ordinary farmland.(3) The main factors affecting fertility are arid climate and geographical location, followed by human factors. This study promotes the utilization of agricultural soil resources in the Weihe River Basin and has important research significance for ensuring food security, economic development, and ecological construction in Shaanxi Province.