水分和有机物料对镉污染土壤的改良效应

通过室内培养和盆栽试验相结合的方式,系统研究了3种土壤水分含量条件下,添加不同有机物料对镉(Cd)污染土壤的改良效应。研究结果表明:淹水、田间持水量和65%相对含水量条件下添加有机物料均有利于污染土壤中可交换态Cd含量的降低,铁锰氧化物及有机结合态Cd含量的增加。随土壤中水分含量的增加,影响程度增加,即淹水>田间持水量>65%相对含水量。3种水分条件下,添加蚯蚓粪处理Cd活性降低明显,其次为猪粪处理,草炭处理相对较差。淹水条件下,油菜体内Cd的含量最低,田间持水量和65%相对含水量条件下油菜部分发育指标差异不显著。添加不同有机物料各处理促进油菜生长的顺序大致为:蚯蚓粪>草炭>CK>猪粪。

Effects of water and organic materials on amelioration of Cd-polluted soil

Incubation and pot experiments were conducted to study the effects of organic materials (grass charcoal, pig manure and earthworm manure) on the amelioration of Cd-polluted soil. The experiment was performed under three water conditions, i.e. submerged, field capacity and 65% relative water content. The results showed that the content of soil exchangeable Cd decreased significantly and FeMnb-Cd, Ob-Cd contents increased after adding organic materials under different water conditions. The effect increased with the increase of soil moisture, i.e. submerged>field capacity >65% relative water content. The effects of organic materials on the availability of Cd were different, with an order of earthworm manure>pig manure>grass charcoal. The growth state of rape in soil at submerged state was better than other water conditions. Some differences of growth indexes of rape were not significant between field capacity and 65% relative water content. The effects of organic materials on the growth of rape were also different, with an order of earthworm manure>grass charcoal >CK>pig manure.