江苏省环太湖地区速效磷和速效钾含量时空变化研究

对土壤养分时空变异的充分了解是土壤养分管理和合理施肥的基础。本文以江苏省环太湖地区为例,利用1982年全国第二次土壤普查成果和2004年的野外采样数据,以速效磷和速效钾为指标,通过传统的统计学和GIS地统计技术,探讨区域尺度上土壤速效养分的时空变化规律。结果表明:从1982年到2004年,研究区土壤速效磷和速效钾的含量都有所增加,前者增加更为显著。速效磷和速效钾含量为Ⅱ级的土壤面积分别增加了12.5%和13.6%,Ⅲ级的土壤面积则分别有8.9%的增加和13.4%的减少,速效磷含量为Ⅳ级的土壤面积减少了21.3%,速效钾含量为Ⅲ、Ⅰ级以及速效磷含量为Ⅰ级的土壤面积都有不到1%增减。土壤速效磷增幅最大的区域在常熟市东部和宜兴市的环太湖地区,武进市东部降幅最大。土壤速效钾含量在宜兴市南部和无锡市区西北部增加最明显,宜兴市中北部、太仓市和张家港市则有明显下降。研究结果可为本区土壤质量的综合研究和管理决策提供依据。

Spatial-temporal Variation of soil available P and K in Taihu Lake region of Jiangsu province, China

Better understanding of soil nutrient spatial．temporal variability is the basis for rational soil management and fertilization．In this paper，spatial and temporal variability of soil available nutrients was analyzed in the studv area surrounding Taihu lake in Jiangsu province，taking available phosphorus(AP)and available potassium(AK)as two indicators，with the data from the Second National Soil Survey in 1982 and field sampling in 2004．bv traditional statistic and geostatistical technologies．The results showed that the average content of soil AP and AK went up from 1 982 to 2004．and the former increased more significantly．The area with levelⅡAP and AK content increased by 12.5% and 13.0%． respectively，and the area of levelⅢAP and AK content increased by 8.9％and decreased bv 13.4％．respectivelv．The area of level IVAP content decreased by 21．3％，and the area of levelⅣand I AK content，and level I AP content changed less than 1％．The largest increasing region of soil AP content was in the east of Changshu and around Taihu lake area of Yixing，and the largest decreasing area was in the east of Wujin．The content of soil AK increased obviouslv in the south of Yixing and the northwest of Wuxi，and decreased in mid-north of Yixing，Taicang and Zhangjiagang．These results provide a theoretical foundation for integrating research and management of soil quality in the studv area．