猪场粪水施用对设施白菜及土壤重金属的影响

Effects of pig farm slurry application on heavy metals in the cabbage and soil

为了研究养殖粪水在农田施用过程中对重金属含量积累、有效性增强以及形态变化等产生的影响,采取田间小区试验,探究了猪场粪水施用对设施白菜地上部重金属含量和土壤重金属全量、有效态含量及形态的影响。结果表明:粪水施用后,低量粪水施用处理与优化施肥(NOPT)处理白菜地上部Cu、Zn、Cr、Cd含量无显著差异,白菜地上部Cu、Zn、Cr、Pb、As、Cd含量均未超出《食品安全国家标准食品中污染物限量》(GB 2762—2017)安全限值要求。经过4茬设施白菜种植后,相较于NOPT处理,561 kg·hm^(-2)粪水施用处理显著增加了土壤Cu、Zn、Cr含量,281 kg·hm^(-2)粪水施用处理土壤中Cu、Zn(0~20 cm土层除外)、Pb、Cr、Cd、As含量与NOPT处理差异不显著,且含量均低于《土壤环境质量农用地土壤污染风险管控标准(试行)》(GB 15618—2018)安全限值。施用化肥和粪水显著提高了土壤有效态Cu、Zn含量,施用粪水处理对土壤中Cr、Pb、As、Cd形态影响较小,但显著增加了铁锰结合态Zn含量。相关分析表明,土壤有效态Cu、Zn、Cr、Cd、Pb含量与土壤有机质、速效磷、全氮、硝态氮含量存在显著正相关关系,与pH值呈显著负相关关系。研究表明,连续4茬施用猪场粪水未造成设施白菜和土壤中重金属含量超标,显著增强了Cu、Zn的有效性且显著增加了铁锰结合态Zn含量。

It is important to study the accumulation of heavy metals in the process of farmland application of pig farm slurry because of potential impacts such as effectiveness enhancement and morphological changes.This study conducted field experiments to explore the effects of pig farm slurry application on the contents,available states,and forms of heavy metals in facility cabbage and soil.The results showed that there was no significant difference between the application of slurry treatment and optimized fertilization(NOPT),with low Cu,Zn,Cr,Pb,As,and Cd contents in the shoots of the cabbage.The Cu,Zn,Cr,Pb,As,and Cd contents did not exceed the safety limit value of the Limits of Contaminants in Foods(GB 2762-2017).After four crops of facility cabbage were planted,compared with those of NOPT,561 kg·hm^(-2) of slurry application treatment significantly increased the soil Cu,Zn,and Cr contents,the Zn(except for in the 0~20 cm soil layer),Pb,Cr,Cd,and As contents in the 281 kg·hm^(-2) of slurry application treatment and NOPT were not significantly different,and the Cu,Zn Cr,Pb,As and Cd contents were lower than the safety limit value of the Soil Environmental Quality Risk Control Standard for Soil Contamination of Agricultural Land(GB 15618-2018).The application of chemical fertilizers and manure water significantly increased the soil effective Cu and Zn contents.The manure water treatment had little effect on the morphology of the Cr,Pb,As,and Cd in the soil,whereas it significantly increased the content of Fe-Mn-bound Zn.Correlation analysis showed that soil available Cu,Zn,Cr,Cd,and Pb had a significant positive correlation with soil organic matter,olsen P,total nitrogen,and NO3-N,and a significant negative correlation with pH.Four consecutive applications of manure water will not pose a the risk of the soil heavy metals content exceeding the standard.Studies have shown that four consecutive applications of manure water did not pose the content of heavy metals in the facility cabbage and soil to exceed the standard,significantly enhance the effectiveness of Cu and Zn,and significantly increase the content of Fe-Mn-bound Zn.