Bilgili Ali Volkan, Küçük Çiğdem, Van Es Harold M
Agriculture Faculty, Department of Plant Nutrition and Soil Science, Harran University, Şanlıurfa, Turkey.
Faculty of Arts and Science, Department of Biology, Harran University, Şanlıurfa, Turkey.
Environ Monit Assess. 2017 Aug 19;189(9):460. doi: 10.1007/s10661-017-6177-y.
Soil quality refers to the ability of soils to perform their functions well. The soils of the Harran Plain, Turkey, have been put into intensive crop production with the introduction of an irrigation scheme and become increasingly degraded due to unsustainable management and cropping systems that resulted in the loss of production potential. The goal of this study was to quantify the quality of common soil series in the Plain using soil quality indexes (SQI) and to compare SQIs of two long-term crop rotations, cotton and wheat-corn cultivation, and different soil types. Over 400 samples were collected at a 0- to 30-cm depth and analyzed for 31 soil variables. The best representative soil quality variables forming a minimum data set (MDS) were selected using principal component analysis (PCA), and soil quality scores were obtained using both linear and non-linear scoring functions. The MDS included three physical (hydraulic conductivity, bulk density, and plant available water content), two biological (soil organic matter and catalase enzyme activity), and nine chemical soil quality indicators (CEC, pH, plant available Cu and Fe, exchangeable Na and K, soluble Ca, Mg, and Na). Because of the low level of SOM, soil qualities were overall low with indexes obtained using two scoring functions ranging from 38.0/100 to 48.7/100. Correlations between SQI obtained using two approaches (linear vs. non-linear; r > 0.61) and using two data sets (all data vs. MDS; r > 0.79) were high. Non-linear scoring functions were more sensitive to management impacts. ANOVA models testing the individual impacts of soil types and crop management on soil quality were statistically different (p < 0.01), but the models including interactions were not. Overall, the fields under cotton cultivation were generally associated with higher clay contents and had the lowest SQIs as a result of intensive cultivation.
土壤质量是指土壤良好发挥其功能的能力。随着灌溉系统的引入，土耳其哈兰平原的土壤被用于集约化作物生产，由于不可持续的管理和种植制度导致生产潜力丧失，土壤质量日益退化。本研究的目的是利用土壤质量指数（SQI）量化该平原常见土壤系列的质量，并比较两种长期作物轮作（棉花种植和小麦 - 玉米种植）以及不同土壤类型的土壤质量指数。在0至30厘米深度采集了400多个样本，并对31种土壤变量进行了分析。使用主成分分析（PCA）选择形成最小数据集（MDS）的最佳代表性土壤质量变量，并使用线性和非线性评分函数获得土壤质量分数。MDS包括三个物理指标（水力传导率、容重和植物有效含水量）、两个生物指标（土壤有机质和过氧化氢酶活性）以及九个化学土壤质量指标（阳离子交换量、pH值、植物有效铜和铁、交换性钠和钾、可溶性钙、镁和钠）。由于土壤有机质含量较低，使用两种评分函数得到的土壤质量总体较低，指数范围为38.0/100至48.7/100。使用两种方法（线性与非线性；r > 0.61）和两种数据集（所有数据与MDS；r > 0.79）获得的SQI之间的相关性很高。非线性评分函数对管理影响更敏感。检验土壤类型和作物管理对土壤质量的个体影响的方差分析模型在统计学上存在差异（p < 0.01），但包含相互作用的模型则没有差异。总体而言，棉花种植田通常粘土含量较高，由于集约化种植，其土壤质量指数最低。
