Department of Soil Science, Faculty of Agriculture, Urmia University, Urmia, Iran.
Department of Research and Development, Monty's Plant Food, 4800 Strawberry Lane, Louisville, KY, 40209, USA.
Environ Monit Assess. 2023 Jul 29;195(8):1007. doi: 10.1007/s10661-023-11610-1.
Land elevation exerts a significant influence on soil fertility through affecting macro and micro climatic conditions and geomorphological processes. To evaluate the soil fertility at different elevation classes, namely 1600-2000, 2000-2400, 2400-2800, and > 2800 m, 350 surface soil samples (0-30 cm) were collected from the agricultural lands of northwestern Iran. Soil properties, including soil texture, calcium carbonate (CaCO), pH, electrical conductivity (EC), organic matter (OM), and soil macronutrients (TN, P, and K) and micronutrients (Fe, Mn, Zn, and Cu), were measured. Finally, the interpretation and classification of the soil samples were made using the nutritional value index (NIV). The comparison of the NIV index based on elevation changes showed that the Gomez method classifies the soil properties in an optimal order as evidenced by its tendency towards the center of the data. However, the Common method is more consistent with the observed trend. After classifying the NIV index using the Common method, it was determined that CaCO and soil salinity are not the limiting factor for soil fertility in different elevation classes. However, in all elevations, high pH, low OM at elevations > 2800 m, total nitrogen (TN), available phosphorous (AP), and micronutrients deficiencies, except Zn at the elevation of 1600-2000 m, are the main limiting factors for soil fertility of agricultural lands. The results provide further insight into the elevation-based land evaluation and may supports grower's decision on nutrient management and crop selection strategies.
海拔通过影响宏观和微观气候条件以及地貌过程对土壤肥力产生重大影响。为了评估不同海拔高度（1600-2000 米、2000-2400 米、2400-2800 米和>2800 米）的土壤肥力，从伊朗西北部的农业用地中采集了 350 个表层土壤样本（0-30 厘米）。测量了土壤性质，包括土壤质地、碳酸钙（CaCO）、pH 值、电导率（EC）、有机质（OM）和土壤大量营养元素（TN、P 和 K）和微量元素（Fe、Mn、Zn 和 Cu）。最后，使用营养值指数（NIV）对土壤样本进行解释和分类。基于海拔变化的 NIV 指数比较表明，Gomez 方法按照最优顺序对土壤性质进行分类，因为其趋势更接近数据中心。然而，通用方法与观察到的趋势更为一致。使用通用方法对 NIV 指数进行分类后，确定 CaCO 和土壤盐分不是不同海拔高度土壤肥力的限制因素。然而，在所有海拔高度下，高 pH 值、2800 米以上地区的 OM 含量低、总氮（TN）、有效磷（AP）和微量元素缺乏，除了 1600-2000 米海拔高度的 Zn 外，是农业用地土壤肥力的主要限制因素。研究结果为基于海拔的土地评估提供了更深入的了解，并可能支持种植者在养分管理和作物选择策略方面做出决策。
