茶树枝生物质炭对农田土壤肥力与水稻镉吸收和转运的影响

Effects of tea branch biochar on soil fertility and cadmium absorption and transport in rice

开展受污染耕地治理技术探索,是确保耕地合理利用与缓解资源紧张的重要措施。该研究以茶树枝进行生物质炭烧制,在镉污染稻田中通过设置3种不同用量(3000、6000和9000 kg·hm^(-2))茶树枝生物质炭开展田间试验,探究茶树枝生物质炭对稻田土壤养分、有效态镉、水稻生长与镉吸收和转运的影响,结果表明,中用量生物质炭处理千粒重、株高、产量与空白对照处理相比分别增加5.04%、9.00%和3.77%,籽粒镉含量下降46.67%,显著降低镉在水稻体内的富集和转运系数。同时土壤pH值增加0.23,有机质含量、碱解氮含量、有效磷含量、速效钾含量分别增加11.41%、13.77%、8.28%、40.94%,土壤有效态镉含量下降13.04%。综合来看,采取茶树枝生物质炭6000 kg·hm^(-2)用量时,能够实现水稻增产与降镉,同步提升土壤肥力的目标,可作为安全利用技术措施进行推广应用。

The exploration of contaminated cultivated land treatment technology is an important measure to ensure the rational utilization of cultivated land and alleviate the shortage of resources.In this study,tea branch biochar was used to conduct field experiments in cadmium-contaminated paddy fields by setting three different amounts(3000,6000 and 9000 kg·hm^(-2))to explore the effects of tea branch biochar on soil nutrients,available cadmium,rice growth and cadmium absorption and transport.The results showed that the 1000-grain weight,plant height and yield of medium dosage biochar treatment increased by 5.04%,9.00%and 3.77%,respectively,compared with the blank control treatment,and the grain cadmium content of medium dosage biochar treatment decreased by 46.67%,which significantly reduced the biological concentration factor and translocation factor of cadmium in rice.At the same time,the soil pH value of medium dosage biochar treatment increased by 0.23,the contents of organic matter,alkali-hydrolyzable nitrogen,available phosphorus and available potassium of medium dosage biochar treatment increased by 11.41%,13.77%,8.28%and 40.94%,respectively,and the content of available cadmium in soil of medium dosage biochar treatment decreased by 13.04%.In summary,when the amount of tea branch biochar was 6000 kg·hm^(-2),the goal of increasing rice yield and reducing cadmium,and simultaneously improving soil fertility could be achieved,which could be promoted and applied as a safe utilization technical measure.