伊犁新垦区土壤养分特征与土地开垦的方向探讨

研究伊犁新垦区土壤养分的空间分布特征及其变化规律，对于合理开发利用土壤资源、优化施肥、建设稳产高产农田等具有重要意义。本文基于实测土壤剖面数据，运用数理统计、地统计学和GIS空间分析方法，研究了伊犁新垦区土壤最上部两层养分的统计特征、空间分布和空间变异，并进行了克里格插值，得到了区域养分的分布图；在此基础上探讨了研究区土地开垦和利用中需注意的问题。研究结果表明：①研究区表土层和第二层的土层厚度平均为10.49cm和19.58cm。表土层和第二层的有机质含量平均为13.72g/kg和10.08g/kg。表土层和第二层的有效氮含量平均为42.54mg/kg和33.98mg/kg，表土层和第二层的有效磷含量平均为12.22mg/kg和4.22mg/kg，表土层和第二层的速效钾含量平均为433.54mg/kg和326.40mg/kg。大部分土壤呈碱性，第二层土壤的碱性比表土层更强；②土壤最上部两层的有机质含量和有效氮含量均呈显著的正相关。土壤有效磷含量和土层厚度呈显著的负相关；③土壤最上部两层的有机质和有效氮的空间变异较大，其次是速效钾、有效磷和土层厚度，PH值的空间变异最小；④土壤最上部两层的有机质、有效磷、速效钾和PH值的空间自相关范围分别是116km、147km、42km和147km。表土层、第二层有效氮的空间自相关范围分别是65km和7km。表土层、第二层的土层厚度的空间自相关范围分别是17km和147km；⑤研究区被开垦时，应适当使用氮肥和磷肥，不必使用钾肥。

Soil Nutrient Properties and Land Development in the Newly Reclaimed Area of Yili, Sinkiang Municipality, China

It is of utmost importance for properly utilizing and protecting land resources, optimizing their fertilization and improving farmland yield to examine spatial distributions and variability in soil nutrients. In the present work, 69 soil profiles and 134 soil samples obtained in a field investigation were used to explore the soil nutrient characteristics in two top layers over the newly reclaimed area of Yili, Sinkiang Municipality, China. First, six indexes were selected to capture the soil nutrients, i.e., layer thickness, soil organic matter, available nitrogen (N), available phosphorus (P), available potassium (K) and PH value. Second, statistics, spatial correlation and spatial variability of soil in two top layers were analyzed using the conventional statistics, geo-statistics and GIS spatial analysis techniques. Third, the Kriging interpolation technique was utilized to derive the spatial distributions of soil nutrients characteristics over the newly reclaimed area of Yili. Finally, on the basis of derived spatial distributions and characteristics of soil nutrients, some suggestions were given on land use and land development over the study area. Results showed that mean layer thicknesses were averagely 10.49 cm and 19.58 cm in topsoil and subsoil, respectively. Likewise, soil organic matter contents were 13.72g/kg and 10.08g/kg, available N contents 42.54mg/kg and 33.98mg/kg, available P contents 12.22mg/kg and 4.22mg/kg, available K contents 433.54mg/kg and 326.40mg/kg, respectively. In general, mean PH value was higher than 7, showing alkaline. It was found that soil organic matter and available N exhibited a strong spatial correlation, while available P and layer thickness were negatively correlated in two top layers. Soil organic matter and available N had the strongest spatial variability in two top layers, followed by available K, available P, layer thickness, and PH values. It was also found that ranges of spatial autocorrelation of soil organic matter, available P, available K and PH values were averagely 116 km, 147 km, 42 km and 147 km in two top layers. By contrast, ranges of available N were 65 km and 7 km and ranges of layer thickness were 17 km and 147 km in the topsoil and subsoil. It was suggested that N and P fertilizer should be appropriately used and K fertilizer should not be necessarily utilized over the study area. In addition, attentions should be paid over where the soil shows strong alkaline, or has thin layer thickness occurring over the middle of the South Channel Irrigation Area, or has poor soil organic matter over the west of the North Irrigation Area of the Yili River.