中度含镉鸡粪源有机肥对土壤镉积累及小白菜吸镉量的影响

Effects of chicken manure source organic fertilizer of moderately cadmium-containing on cadmium accumulation in soil and cadmium absorption in Chinese cabbage

为探讨施用鸡粪源有机肥对土壤-作物系统累积重金属镉的影响,实现鸡粪源有机肥的安全利用,以种植一季小白菜盆栽试验方式,选择镉含量适中(Cd 1.58 mg·kg^-1)的鸡粪源有机肥,以不施肥空白(CK)和化肥常规施肥处理(F)为对照,在与常规肥施加等量化肥的基础上,设置4种不同施肥量有机肥处理,分析施用鸡粪源有机肥对土壤基本理化性质和土壤镉累积量及小白菜镉吸收量的影响。结果表明:鸡粪源有机肥施用量为0.5~2 g·kg^-1时土壤全氮、碱解氮、速效钾及有效磷含量较高,分别为0.725~0.760 g·kg^-1、111.50~141.48mg·kg^-1、205.86~230.44 mg·kg^-1、19.13~28.54 mg·kg^-1,土壤有机碳为10.27~11.84 g·kg^-1,但种植一季对土壤机械组成和阳离子交换量无明显影响。总体来看,随着鸡粪源有机肥施用量的增加,土壤pH值呈现缓慢降低趋势,对土壤累积镉影响不明显,土壤中镉的可交换态和可还原态含量呈增加趋势,可氧化态和残渣态含量呈减少趋势,而小白菜地上可食用部分镉的累积量有降低趋势。综上,鸡粪源有机肥的施加有助于改善土壤基本理化性质,影响镉在土壤中的形态分布,在种植一季小白菜时对土壤累积镉影响不明显,但有助于降低小白菜地上可食用部分的镉累积量。

In order to explore the effect of applying chicken manure source organic fertilizer on the accumulation of heavy metal cadmium in soil-crop system and realize the safe utilization of chicken manure source organic fertilizer,the chicken manure source organic fertilizer with moderate cadmium content(cadmium concentration is 1.58 mg·kg-1)was selected by pot experiment of Chinese cabbage,soil basic physical and chemical properties and the accumulation of heavy metal cadmium in soil and absorption in Chinese cabbage were analyzed.Six treatments were set up,including no fertilizer control(CK),conventional fertilizer(F),and four different organic fertilizer treatments with different manure application levels on the basis of applying the same amount of chemical fertilizer as the conventional fertilizer treatment.The results showed that the contents of total nitrogen,alkali-hydrolyzed nitrogen,available potassium and available phosphorus in soil were higher when the application amount of organic fertilizer was 0.5~2 g·kg-1,which were 0.725~0.760 g·kg-1,111.50~141.48 mg·kg-1,205.86~230.44 mg·kg-1,19.13~28.54 mg·kg-1,respectively,and the content of soil organic carbon were 10.27~11.84 g·kg-1,but the soil texture and cation exchange capacity had no significant changes after cabbage planting.With the increase of the application amount of chicken manure source organic fertilizer,the overall pH value of the soil showed a slow decreasing trend,and the accumulation of cadmium in the soil was not obviously changed,the content of exchangeable and reducible state of cadmium in soil increased,and oxidizable and residue state of cadmium decreased,moreover,the accumulation amount of edible cadmium in the ground of Chinese cabbage showed a decreasing trend on the whole.In conclusion,the application of chicken manure source organic fertilizer helps to improve the basic physical and chemical properties of soil,and affects the form and distribution of cadmium in soil,it has no obvious influence on the accumulation of heavy metal cadmium in soil when planting one season of Chinese cabbage,but helps to reduce the accumulation of cadmium in edible parts of Chinese cabbage.