Pollution Research Paper

A SUGGESTION FOR SUSTAINABLE GROUNDWATER USE ONINTENSIVE ARABLE AREA IN SEMIARID REGION

YOUNG-SIK HAM

Abstract

Topsoil and groundwater qualities were investigated by obtaining onsite measurements in the Alxa semiarid region in Inner Mongolia, north western China. The groundwater quality was found to be unacceptable for drinking as the concentration of groundwater nitrate (NO3–) was 66–250mg l–1, with an average value of 130 mg l–1; this value is 1.3–5.6 times higher than that specified by the regulatory drinking water standards recommended by the World Health Organization (50 mgNO3– l–1) or U.S. Environmental Protection Agency (44.26 mg NO3– l–1). The mean values of the groundwater electrical conductivity (EC) and nitrate NO3– in intensive agricultural areas were, respectively, 2.9 and 3.2 times higher than those in non-intensive agricultural areas. In addition, the groundwater EC and NO3– of the intensive and non-intensive agricultural areas exhibited considerable differences (EC: p<0.001, NO3–: p<0.05, Student t-test). This study suggests a sustainable groundwater use (as irrigation water use) without nitrogen fertilization on intensive arable area in semiarid region. The recommended amount of irrigation water use can help improve the degradation of the topsoil and enhance the groundwater qualities while decreasing the surplus N content.