| 龙泽东,孙梅,罗尊长,孙耿,李超,肖小平.长期不同耕作方式与秸秆还田对稻田镉生物有效性的影响[J].农业环境科学学报,2021,40(9):1888-1896. |
| 长期不同耕作方式与秸秆还田对稻田镉生物有效性的影响 |
| Effects of different long-term tillage methods and straw returning on cadmium bioavailability in paddy fields |
| 投稿时间：2021-02-04 |
| DOI：10.11654/jaes.2021-0152 |
| 中文关键词: 耕作方式 秸秆还田 双季稻 镉 生物有效性 |
| 英文关键词: tillage methods straw returning double cropping rice cadmium bioavailability |
| 基金项目:湖南省自然科学基金项目（2019JJ50338）；区域创新发展联合基金项目（U19A2048）；农业部与财政部科研专项（农办财函[2015]38号） |
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| 中文摘要: |
| 以湖南省典型双季稻区的土壤-水稻系统为研究对象，通过长期田间连续定位试验，研究不同耕作方式和秸秆还田对土壤-水稻系统镉生物有效性的影响。试验采用随机区组设计，共设4个处理：翻耕+秸秆不还田（CT）；翻耕+秸秆还田（CTS）；旋耕+秸秆还田（RTS）；免耕+秸秆还田（NTS）。结果表明： NTS处理增加了土壤阳离子交换量，降低了粉粒的比例。NTS处理土壤总镉和离子交换态镉含量分别为（0.48±0.01）mg·kg-1和（0.39±0.01）mg·kg-1，与CTS和RTS处理均无显著差异，但显著高于CT处理。NTS处理早稻和晚稻糙米总镉含量分别高达（0.30±0.04） mg·kg-1和（0.60±0.07） mg·kg-1，超过0.20 mg·kg-1的国家食品安全标准（GB 2762—2017），且显著高于其他处理。水稻糙米中总镉含量和土壤总镉、碳酸盐结合态镉和铁锰氧化物结合态镉含量显著正相关。研究表明，耕作强度越弱土壤中镉的生物有效性越高，秸秆还田相对于不还田处理增加了镉的生物有效性。耕作方式和秸秆还田通过影响土壤镉生物有效性进而影响水稻镉含量，免耕秸秆还田增加了土壤和水稻糙米中的镉，带来了镉超标的安全问题。 |
| 英文摘要: |
| The effects of different tillage methods and straw returning on the bioavailability of cadmium in a soil-rice system in Hunan Province were studied with the aim to provide supporting data for improved soil quality and reduced rice cadmium content in these systems. The trial was randomized and a total of four treatment groups were designed:plow tillage with residue removed(CT); plow tillage with residue retention(CTS); rotary tillage with residue retention(RTS); no-tillage with residue retention(NTS). The study found that the NTS group increased the soil CEC content and reduced the proportion of powder particles. The total cadmium and ion-exchanged cadmium contents in NTS soil were(0.48±0.01) mg·kg-1 and(0.39±0.01) mg·kg-1, respectively. These were not significantly different from the CTS and RTS treatments but were significantly higher than the CT treatments. The total cadmium content of brown rice from early and late rice in NTS were(0.30±0.04) mg·kg-1 and(0.60±0.07) mg·kg-1, respectively, which exceeded the national food safety standards(0.20 mg· kg-1) and were significantly higher than in the other treatment groups. The total cadmium content in brown rice was positively correlated with total soil cadmium, carbonate bound cadmium, and iron-manganese bound cadmium. The weaker the tillage intensity, the higher the bioavailability of cadmium in soil, and the higher the bioavailability of cadmium in straw returning to the field compared with the nonreturn treatment. Tillage methods and straw returning affect the cadmium content in rice by affecting soil bioavailable cadmium. No-tillage with straw returning to the field increases the cadmium content in soil and brown rice, resulting in unsafe cadmium levels that exceed the national food safety standards. |
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