长江三角洲典型地区土壤性质对土地利用变化的响应—以江苏省锡山市为例

以锡山市为分析样区,对土壤pH、有机质、全氮、全磷、速效氮、速效磷和速效钾等7个指标对旱地变为未利用地、水田变为菜地、水田变为旱地、水田变为林地和水田变为未利用地等五种变化方式的响应进行了研究.结果表明,土地利用变化对土壤性质有显著影响,但不同变化方式对各指标的影响方向及影响程度不同：（1）水田变为菜地、旱地和林地使土壤向酸化方向发展,土壤pH分别降低0.47、0.78和0.17;旱地和水田变为未利用地分别使土壤pH提高0.24和0.74;（2）水田变为未利用地、菜地和林地分别使有机质降低3.83、3.18和0.35 g kg^-1;水田变为旱地、旱地变为未利用地分别使有机质含量增加7.58和1.07 g kg^-1;（3）旱地变为未利用地、水田变为菜地和未利用地分别使全氮降低0.31、0.08和0.11 g kg^-1;水田变为旱地和林地分别使全氮提高0.41和0.04 g kg^-1;（4）旱地变为未利用地使全磷有微小幅度的降低,降低量为0.01 g kg^-1;水田变为菜地、旱地、林地和未利用地后不同程度地提高全磷含量,增加量分别为0.23、0.08、0.23和0.09 g kg-1;（5）旱地和水田变为未利用地分别使速效氮降低2.38和7.62 mg kg^-1;水田变为菜地、旱地和林地分别使速效氮增加11.61、34.51和18.26 mg kg^-1;（6）旱地变为未利用地使速效磷降低3.70 mg kg^-1;水田变为菜地、旱地、林地和未利用地分别使速效磷增加45.16、7.54、40.55和10.94 mg kg^-1 ;（7）旱地变为未利用地以及水田变为菜地、旱地、林地和未利用地均使速效钾含量有所增加,增加量分别为8.75、77.44、32.28、160.4和27.59 mg kg^-1.

RESPONSES OF SOIL PROPERTIES TO CHANGE IN LAND USE IN A TYPICAL AREA OF THE YANGTZE RIVER DELTA——A CASE STUDY OF XISHAN CITY,JIANGSU PROVINCE,CHINA

Xishan City,a typical area of the Yangtz River Delta,was selected as a case for study of responses of 7 soil fertility indices,such as soil pH,organic matter(OM),total nitrogen(TN),total phosphorus(TP),available nitrogen(AN),available phosphorus(AP),and available potassium(AK),to changes in land use,i.e.from dry-land to unused land(DCU),from paddy field to vegetable field(PCV),from paddy field to dry-land(PCD),from paddy field to forest land(PCF),and from paddy field to unused land(PCU),in Yangtze River Delta.Results show that changes in land use did significantly affect soil properties to a varying degree.1) PCV,PCD and PCF led to decrease in soil pH by 0.47,0.78 and 0.17,respectively,while DCU and PCU to increase by 0.24 and 0.74,respectively;2) PCU,PCV and PCF led to decrease in content of OM by 3.83,3.18 and 0.35g kg-1,respectively,while PCD and DCU to increase by 7.58 and1.07 g kg-1 respectively;3) DCU,PCV and PCU led to decrease in content of TN by 0.31,0.08 and 0.11 g kg-1,while PCD and PCF to increase by 0.41and 0.04 g kg-1,respectively;4) DCU led to decrease in content of TP slightly by 0.01 g kg-1,while PCV,PCD,PCF and PCU to increase by 0.23,0.08,0.23 and 0.09 g kg-1,respectively;5) DCU and PCU led to decrease in content of AN by 2.38 and 7.62 mg kg-1,while PCV,PCD and PCF to increase by 11.61,34.51 and 18.26 mg kg-1,respectively;6) DCU led to decrease in content of AP by 3.70 mg kg-1,while PCV,PCD,PCF and PCU to increase by 45.16,7.54,40.55 and 10.94 mg kg-1,respectively;and 7) DCU,PCV,PCD,PCF and PCU led to increase in content of AK by 8.75,77.44,32.28,160.4 and 27.59 mg kg-1,respectively.