根据2014年采集的121个耕层(0~20 cm)土壤氮素含量数据,在Arc GIS 10.0平台上运用地统计学、缓冲区分析和叠置分析等方法,研究崇州西河流域土壤氮素的空间分布特征及其影响因素。结果表明,该区土壤全氮和碱解氮含量分别达(1.18±0.40)g kg~(-1)和(86.52±28.71)mg kg~(-1),存在中等程度的空间变异。其中,全氮总体呈环状分布,而碱解氮则呈斑块状或条带状分布,二者均在中部怀远镇附近出现高值区(>1.80 g kg~(-1),>120 mg kg~(-1)),而在北部街子-三郎山区一带和南部丘顶出现低值区(<0.95 g kg~(-1),<60 mg kg~(-1))。影响因素分析表明,土壤氮素在平原区含量显著高于山区和丘陵区。由紫灰沉积物和再积黄泥发育而来的土壤氮素含量显著高于沙页岩残坡积物和紫色沉积物。从不同农地利用方式来看,水稻-小麦轮作下土壤氮素平均含量最高。在道路和河流的2.5 km缓冲范围内,土壤氮素存在不同的变化趋势,自然地质过程对其主控作用总体大于人为活动因素。
【英文摘要】
Soil nitrogen was a vital nutrient to enhance plant growth. According to the data of soil nitrogen content collected from 121 random grid and hierarchical sampling points in top soil in 2014,spatial distribution characteristics and their influential factors of soil nitrogen in West River Valley were analyzed using the software Arc GIS 10. 0 with geostatistics and spatial analysis. Results showed that the content of soil total nitrogen(TN) and available nitrogen(AN) were(1. 18 ± 0. 40) g·kg~(-1)and(86. 52 ± ...