有机废液对镉污染土壤上白菜生长和镉积累影响

为探究有机废液在镉污染土壤施用对作物生长和环境健康风险的影响，该研究针对豌豆发酵液、玉米浆浓缩液、鸡粪浓缩沼液、糖蜜液和氨基酸母液5种价格低廉且在农业中应用广泛的有机废液，通过盆栽试验分析了施用2 ml/kg的5种有机废液对白菜生长与镉吸收的影响，并从白菜光合作用及抗氧化酶活性等角度进行了效果对比研究。结果表明，除氨基酸母液处理外，豌豆发酵液、玉米浆浓缩液、鸡粪浓缩沼液、糖蜜液处理较对照均可显著增加镉胁迫下白菜叶片净光合速率（P<0.05），促进白菜生长，其中施用玉米浆浓缩液分别使白菜地上部和地下部干质量提高了21.66%和68.75%。与对照相比，施用玉米浆浓缩液使白菜地上部的镉浓度降低了22.06%，并显著提高了白菜超氧化物歧化酶和过氧化氢酶活性（P<0.05），糖蜜液和氨基酸母液处理没有降低白菜镉浓度。施用玉米浆浓缩液、鸡粪浓缩沼液、糖蜜液和氨基酸母液均可显著降低白菜丙二醛含量（P<0.05），提高土壤有效态镉含量。综上，5种有机废液对镉污染条件下白菜生长和镉吸收转运的影响不同，玉米浆浓缩液促进白菜生长并减少镉积累效果最好，氨基酸母液效果最差。

Effects of organic waste liquids on Chinese cabbage growth and cadmium accumulation in cadmium-contaminated soils

Organic waste liquids can be one of the most important sources of fertilizer used for sustainable production. However it is still unclear on the risks associated with their application in cadmium-containing contaminated farmland. This study aims to investigate the effects of organic waste liquids that are applied to the cadmium-contaminated soil on crop growth and environmental health risks. A series of potting experiments were performed on the growth and cadmium accumulation of Chinese cabbage. Five low-cost and commonly used organic waste liquids were taken as the pea fermentation liquid, corn syrup concentrate, chicken manure concentrated swamp liquid, molasses liquid, and amino acid mother liquor. These organic waste liquids were added into the soil at a dose of 2 ml/kg in advance, and then the Chinese cabbage was sown after 24h of standing time. Some parameters were determined in the Chinese cabbage grown for 35 days, including the growth indexes, photosynthetic characteristics, malondialdehyde (MDA) content, and antioxidant enzyme activities, together with the aboveground and belowground cadmium concentrations of Chinese cabbage and cadmium in the active state in the soil. Moreover, the correlation and cluster analysis were utilized to clarify the correlation between the indicators and the relationship between the five organic waste liquids. The results showed that the pea fermentation liquor, corn syrup concentrate, chicken manure concentrate swamp liquid, and molasses liquid treatments promoted the growth of Chinese cabbage, except for the amino acid mother liquor. There was an increase in the net photosynthetic rate and a decrease in the MDA content of Chinese cabbage leaves under cadmium stress. Among them, the chicken manure-concentrated swamp liquid and corn syrup concentrate shared the most significant positive effect on Chinese cabbage growth. The height of Chinese cabbage plants increased by 15.21% and 12.58%, respectively, compared with the control treatment. Furthermore, the application of corn syrup significantly increased the aboveground and belowground dry weight of the Chinese cabbage plants by 21.66% and 68.75%, respectively, compared with the control treatment. There was also a significant increase in the activities of antioxidant enzymes in the Chinese cabbage plants (P<0.05), such as superoxide dismutase (SOD) and catalase (CAT). Corn syrup concentrate was the most effective in reducing the aboveground cadmium content of Chinese cabbage, followed by chicken manure concentrate treatment, which reduced the aboveground cadmium concentration of Chinese cabbage by 22.06% and 7.83%, compared with the control, respectively. Both of them also significantly reduced the cadmium transfer coefficient of Chinese cabbage plants (P<0.05). However, there was no reduce in the cadmium concentration and cadmium transfer coefficient in Chinese cabbage under the molasses liquid and the amino acid mother liquor. There was a significant increase in the cadmium enrichment coefficient, compared with the control treatment, indicating the potential health risks associated with their practical application. The corn syrup concentrate, chicken manure concentrated swamp liquid, molasses liquid and amino acid mother liquor increased the cadmium content in the soil effective state. Therefore, there were different effects of the five different organic waste liquids on Chinese cabbage growth and cadmium accumulation in the cadmium-contaminated soils. Corn syrup concentrate demonstrated great potential to promote crop growth with less cadmium uptake. The wide application was highly expected in real cases. This finding can provide a valuable reference for the resource utilization of organic waste liquid.