Abstract: Studies on the effect of simulated acid rain on mung beau and maize show that the chlorophyll content, chlorophyll a/b values and leaf vitality of these crops and the PH values ofleaf sap and soil are positively correlated with the PH value of simulated acid rain, andtheir relative conductivity, peroxidase activity and proline content are negatively correlated with it. The SOD activity is decreased with decreasing PH of acid rain.

Key words: Simulated acid rain, Eco-physiology, Mung bean, Maize, mechanically harvested cotton, fiber quality, water use efficiency, seed cotton yield, nitrogen partial factor productivity, water and nitrogen regulation