| 稻-麦轮作模式下不同钝化材料对镉污染农田土壤的原位钝化效应 |
| 摘要点击 2418 全文点击 867 投稿时间：2022-04-12 修订日期：2022-06-06 |
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| 中文关键词 钝化材料 镉(Cd) 原位钝化 持久性 稻-麦轮作 |
| 英文关键词 amendments Cd in-situ remediation persistence rice-wheat rotation |
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| 中文摘要 |
| 为明确大田条件下施用钝化材料对镉（Cd）污染农田土壤的原位钝化效应及其持续性，以秸秆生物炭、YH粉、粉煤灰、海泡石和页岩粉（粒径均<0.2 mm，施用量均为2.25kg ·m-2）这5种钝化材料为研究对象，连续监测3 a稻-麦轮作模式下原位钝化处理对土壤养分、土壤酸碱度、土壤Cd污染状况和种植作物籽粒Cd含量的影响，探讨其钝化效应及持续性，为有效控制农田土壤Cd污染、保证作物安全生产提供理论依据和数据支撑.结果表明：①稻-麦轮作模式下，施用5种钝化材料对土壤养分含量影响较小，但均可提高土壤pH，促使土壤Cd由酸提取态向残渣态转化，降低土壤Cd有效性，其中秸秆生物炭与YH粉处理下当季土壤有效Cd含量的降幅最大（20.42%~22.53%），是其它钝化处理的1.07~1.84倍.②稻-麦轮作模式下，首年施用5种钝化材料后均显著降低了水稻和小麦籽粒Cd含量，降幅分别达19.88%~48.77%和5.06%~24.00%.施用秸秆生物炭、粉煤灰和YH粉后作物籽粒Cd含量显著低于对照和其它钝化材料，该处理条件下的水稻籽粒ω（Cd）（0.195、0.197和0.223 mg ·kg-1）达到或接近《食品安全国家标准食品中污染物限量》（GB 2762-2017）.③5种钝化材料对农田土壤Cd的钝化效应随时间的延长均有所减弱，粉煤灰、海泡石和页岩粉在施用后第3 a已无明显钝化效应，而秸秆生物炭和YH粉处理下土壤有效Cd和作物籽粒Cd含量在稻-麦轮作第3 a中仍显著低于对照，钝化效果持久性较好.5种钝化材料施用第3 a时效果已迅速衰减，但秸秆生物炭和YH粉仍可明显降低土壤有效Cd和作物籽粒Cd含量，其钝化效果具有较好的持续性，是用于稻-麦轮作模式下Cd污染农田土壤安全生产的理想钝化材料. |
| 英文摘要 |
| Exploring the effects of one-time amendment treatments on cadmium (Cd)-contaminated farmland soils is beneficial for providing a theoretical basis to effectively prevent Cd pollution in farmland soils and ensure the safe production of crops. Five amendments, including straw biochar, fly ash, sepiolite, white marble powder, and shale (particle size <0.2 mm, application rate 2.25 kg·m-2), were applied to the Cd-contaminated farmland soils. The soil nutrients, pH, soil available Cd, and Cd chemical forms in the soils and grain Cd concentration in the planted crops were determined to investigate the effects and persistence of one-time applications of the five amendments. The results showed that:① the application of the five amendments had little effect on soil nutrient content, but all of them could increase soil pH. Amendment treatments improved the transfer of Cd from the acid extraction fraction to residue fraction and further reduced the Cd availability in the soil. The decreasing amplitudes of straw biochar and white marble powder soil conditioner were 20.42%-22.53%, which was higher than those in the other treatments. ② The grain Cd concentrations in rice and wheat were significantly decreased under the amendment treatments with the decreasing amplitudes of 19.88%-48.77% and 5.06%-24.00%, respectively. The Cd concentrations in rice grains under the treatments of straw biochar, fly ash, and white marble powder soil conditioner were 0.195, 0.196, and 0.223 mg·kg-1, respectively, which were lower than those under the other treatments and were close to or approached the National Standard of Food Safety(GB 2762-2017)(0.2 mg·kg-1). ③ The immobilization effects on Cd in farmland soils were decreasing with time under one-time application of the amendments. The available Cd concentrations in the soil and Cd concentrations in crop grains were still lower than those in the control after three rounds of rice-wheat rotation. The straw biochar and white marble powder soil conditioner had a good and long-term effect on reducing Cd availability in soils and Cd concentrations in crop grain, making them ideal materials for safe production in Cd-contaminated soils. |
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