Acta Geographica Sinica ›› 2010, Vol. 65 ›› Issue (7): 789-800.doi: 10.11821/xb201007003

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The Influence of Land Use Change on Soil Development and over the Loess Tablelands in the Northern Weihe River Basin, China

PANG Jiangli, ZHANG Weiqing, HUANG Chunchang, ZHA Xiaochun, ZHANG Caiyun, CHANG Meirong, ZHU Meiling, DING Min   

  1. College of Tourism and Environment Science, Shaanxi Normal University, Xi'an 710062, China
  • Received:2010-01-27 Revised:2010-05-12 Online:2010-07-20 Published:2010-07-30
  • Supported by:

    National Natural Science Foundation of China, No.40471119; No.40771018; Fundamental Research Funds for Central Universities, No.KG200901007

Abstract:

Investigations of land use change and its impact on soil development were carried out over the loess tablelands in the northern Weihe River basin. Typical soil profiles, including 6 cultivated soil and 8 apple orchard soil were surveyed in detail, and then sampled systematically. Pedological characteristics and the structure of soil profiles were observed in the field. Particle-size distribution, magnetic susceptibility, contents of organic matter, CaCO3, trace elements, pH value and micromorphology was analyzed in laboratory. An integration of the results shows that: (1) When cultivated land was converted to apple orchard, the structure of the soil profile changed from Ap-Bc-A-Ck-C to AB-(Bc)-A-Ck-C gradually. (2) Element change occurred in the topsoil between 0 and 35 cm in depth. Magnetic susceptibility, contents of organic matter, major elements (Si, Al, Fe, K, Mg, Ca, Na) and trace elements (Cu, Co, Ni, Zn, Vi, Cr, Pb, Cs) tend to increase, and CaCO3 content and pH value tend to decrease. (3) Between 35 and 90 cm in depth, magnetic susceptibility, contents of organic matter, major and trace elements tend to decrease, and CaCO3 content tends to increase. (4) Soil properties remain unchanged below 90 cm in depth. (5) Soil porosity change is obvious. The number of the soil pores is reduced, and the average area of pores is increased. The total content of clay mineral is increased, the ratio of the residual clay to alluvial clay is reduced. The illuviation depth of secondary calcite in the cultivated soil profile occurred between 0 and 35 cm in depth. However, in apple orchard soil profile, carbonate illuviation extended to the depth of 90 cm in general. All of these evidences show that human land use change has affected soil properties and soil development in a relatively short period of time. After cultivated land was changed into apple orchard, soil properties changed mainly between 0 and 35 cm in depth, and the deeper part between 35 and 90 cm was also affected.

Key words: land use change, cultivated land, apple orchard land, soil profile, loess tablelands, northern Weihe River basin