The soils under different cropping patterns in red hilly regions of southern Hunan Province were investigated in field and analyzed in laboratory, and its acidification, exchangeability and contents of large, medium and micro- nutrient were researched. The results showed that under cropping patterns of A1 (intercropping citrus with watermelon) and C1 (monoculture of watermelon), the exchangeable acid and exchangeable A13+ in soil were lower than those under other cropping patterns, while cation exchange capacity (CEC), effective cation e...