长三角经济高速发展地区土壤pH时空变化及其影响因素

通过调查和分析长三角地区张家港市2004年和第二次土壤普查时(1980)的土壤pH,探讨了该市近20年来基于经济高速发展影响下的土壤pH变化及影响因素。结果表明,自第二次土壤普查以来,该市土壤pH变化明显。南部人为土地区绝大部分土壤pH值都下降了一个单位,平均值由7.39降至6.33;北部雏形土区,两个时期的土壤pH值分别为7.92和7.98。土壤pH的降低可能同该地区长期施用化学肥料、酸雨及工业酸性“三废”排放的增加有关。此外,土地利用和田间管理也对土壤pH变化起着较为重要的作用,而土壤地球化学性质差异则是导致南北地区土壤pH变化不同的内在因素。

Spatial -Temporal Variation of pH Values of Soils in A Rapid Economic Developing Area in the Yangtze River Delta Region and Their Causing Factors

Through the investigation of pH values in soils in the Zhangjiagang County in the Yangtz River delta region in 2004 and the analogy with those pH values of soils in 1980,the spatial-temporal variation of pH values of soils and their causing factors have been discussed in this paper.It is shown that with rapid economic development,significant changes of pH values in soils in the area have been observed since the Second National Soil Survey in 1980.Majority of pH values in anthrosols in the southern part of the area is decreased for about one pH unit,with average pH values decreasing from 7.39 in 1980 to 6.33 in 2004.However,the majority of pH values in cambosols in the northern part of the area is almost not changed,with average pH values of 7.92 in 1980 and 7.98 in 2004 respectively.Heavy application of chemical fertilizers,acid deposition and industrial discharging could be the reasons causing the decrease of pH values in the soils.In addition,land utilization and field management have also played important role for the pH value changes of the soil in the area.It is believed that the difference of the soil geochemical properties in the southern and in the northern parts is the main internal factors causing the different changes of pH values in various types of soils in the northern and southern areas respectively.