模拟酸雨对油菜大田土壤酸化及K,Na,Ca,Mg溶出的影响

Effect of Simulated Acid Rain on Acidification and Dissolution of Potassium,Natrium,Calcium and Magnesium in the Rape Plantation Soil

在油菜大田栽培的自然生态环境条件下,通过喷淋和土柱淋溶试验,研究不同pH模拟酸雨对油菜大田土壤K,Na,Ca和Mg等盐基离子溶出的影响.结果表明:酸雨喷淋和淋溶后油菜大田土壤和淋滤液的pH明显高于酸雨pH;酸雨pH<3.5时,土壤pH主要受酸雨酸度控制,酸雨胁迫起主要作用;酸雨pH>3.5时,土壤pH主要由土壤盐基量制约,缓冲起主要作用;随着喷淋次数和淋溶量的增加,通过缓冲作用可使油菜大田土壤生态环境有所恢复并趋向一致.K,Na,Ca和Mg的溶出量随酸雨pH,淋溶量和淋溶时间的增加而减小,随油菜群体生长量的增大而增大;4种元素中,Ca溶出量最大且变化最明显,相比之下酸雨对油菜大田中K,Na,Mg的释放影响较微弱.

Under the natural ecological condition of rape field cultivation, effect on rape soil and dissolution in the base ions of K, Na, Ca and Mg with different pH of simulated acid rain was investigated by spraying and soil columns leaching experiments. The results show that pH value of rape soil and filtrate liquid was apparently higher than pH value of acid rain after spraying and leaching. The acid rain stress was major factors, and pH of soil was confined chiefly by acidity of acid rain on pH 〈 3.5. The amortizing of soil came into play on pH 〉 3.5 due to the base quantity in soil. The ecological environment on rape plantation soil could be initialized by amortizing in increased spraying and leaching times so that pH value could tend to be balanced. The dissolution of K, Na, Ca and Mg could be decreased with raising pH of acid raln, developing leaching amount and times, and enhanced with rape group growing. Among the four metal elements, Ca had a greater amount and variation. On the other hand, releases of K, Na, Mg in the plantation soil could be feebleness under influence by acid rain.