Effects of simulated acid rain on growth quality of pakchoi under different fertilization conditions

A greenhouse cultivation experiment was conducted to evaluate the effects of different fertilization conditions on chlorophyll, total N, total P, total K accumulation in pakchoi on the whole growth stage under the press of simulated acid rain. The results showed that acid rain had inhibitory effect on the growth of pakchoi. Strong acidity of acid rain (pH ≤ 3.5) had stronger inhibitory effect. The accumulation rates of indices were the highest from the 21st to the 28th day, and higher in inorganic fertilizer treatment in the mature period. Compared with the control group, the loss rates of indices at harvest period of pakchoi treated with simulated acid rain at pH 2.5, 3.5, 4.5, 5.6 were as follows: for chlorophyll content, the inorganic treatment had 27.99%, 15.29%, 7.94%、1.09%, the organic treatment had 25.39%, 7.43%, 0.18%, -2.45%); for total N, the inorganic treatment had 47.28%, 37.04%, 23.58%, 8.65%, the organic treatment had 37.89%, 34.93%, 23.58%, 8.65%; for total P, the inorganic treatment had 49.15%, 25.84%, -3.54%, -1.69%, the organic treatment had 46.69%, 45.11%, 22.15%, 14.53%; for total K, the organic treatment had 55.42%, 35.39%, 8.26%, 6.52%, the organic treatment had 36.43%, 22.62%, 9.57%, 6.85%. Inorganic fertilizer could slow down the chlorophyll loss and NPK accumulation loss of pakchoi under stress of simulated acid rain, while organic fertilizer could slow down the NPK accumulation loss of pakchoi under stress of weak acid rain. According to the acidity situation of acid rain in vegetable growing areas, the appropriate fertilizer to maximize production could be selected.