张源沛,张益明,周会成.半干旱地区春小麦不同种植方式土壤水分变化规律研究初探[J].土壤,2003,35(2):168-170. Zhang Yuanpei, Zhang Yiming, Zhou Huicheng. PRELIMINARY STUDY OF SOIL WATER VARIATION UNDER SPRING WHEAT CULTIVA - TION WITH AND WITHOUT PLASTIC MULCHING IN SEMIARID REGIONS OF NINGXIA[J]. Soils,2003,35(2):168-170