石灰和牡蛎粉对酸性镉污染农田粉葛增产降镉效应

Effects of lime and oyster powder on increasing the yield of and reducing cadmium content in Pueraria thomsonii in acid cadmium–contaminated farmlands

为探究含钙物质对酸性镉污染农田粉葛生长及镉富集特征,以江西省新余市酸性镉污染土壤为研究对象,研究了施用石灰和牡蛎粉2种钙素材料对土壤化学性质、粉葛各部位镉含量及生物量的影响。结果表明,与对照比,施钙(石灰、牡蛎粉)处理显著提高了土壤pH(0.85~0.87个单位),显著降低了土壤有效态镉含量(53.85%),施钙处理还降低了镉在粉葛体内富集。与对照相比,石灰处理粉葛总生物量、产量和收益分别增加了34.26%、38.20%和107.15%,块根和葛粉中镉含量分别降低了34.09%和15.38%。与对照相比,牡蛎粉处理粉葛总生物量、产量和收益分别增加了42.46%、38.07%和173.08%,块根和葛粉中镉含量分别降低了63.64%和69.23%,其中以牡蛎粉处理的增产降镉效果最佳。相关分析表明,粉葛生物量及产量与土壤pH呈显著正相关(P<0.05),与土壤镉含量呈显著负相关(P<0.05);粉葛各部位镉含量与土壤pH呈显著负相关(P<0.05),与土壤中镉含量呈显著正相关(P<0.05)。综上,在镉污染耕地上施用牡蛎粉(2250 kg·hm^(-2))更有利于促进粉葛的生长,提高粉葛产量、品质及收益,同时还能有效降低镉在粉葛体内的富集,实现粉葛安全生产。

This study aimed to determine the effects of calcium-containing substances on the growth and cadmium enrichment characteristics of Pueraria thomsonii in acid cadmium–contaminated farmlands.The acid cadmium–contaminated soil in Xinyu,Jiangxi Province,was utilized for field experiments.The effects of lime and oyster powder on soil physicochemical properties and P.thomsonii cadmium content and biomass were studied.The results showed that,compared with the control,calcium application significantly increased soil pH(0.85–0.87 units)and reduced the available cadmium content(53.85%).Treatment with calcium also effectively reduced cadmium accumulation in P.thomsonii.Compared with the control,lime treatment increased the biomass and yield of and income from P.thomsonii by 34.26%,38.20%,and 107.15%,respectively;however,it decreased the cadmium content in tubers and arrowroot by 34.09%and 15.38%,respectively.Compared with the control,oyster powder treatment could increase the biomass and yield of and income from P.thomsonii by 42.46%,38.07%,and 173.08%,respectively;the cadmium content in tubers and arrowroot decreased by 63.64%and 69.23%,respectively.Oyster powder treatment exerted the best effect on increasing the yield of and reducing cadmium content in P.thomsonii.The correlation showed that the biomass and yield of P.thomsonii were positively correlated with soil pH(P<0.05)but negatively correlated with soil cadmium content(P<0.05).The cadmium content in P.thomsonii tissues was significantly negatively correlated with soil pH(P<0.05)but positively correlated with soil cadmium content(P<0.05).Under cadmium pollution,the application of oyster powder(2250 kg·hm^(-2))to P.thomsonii was beneficial in promoting its growth,improving its yield and quality,and generating considerable revenue.Additionally,oyster powder application successfully reduced cadmium enrichment and accomplished the safe planting of P.thomsonii.