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我国传统水稻种植多采用冬闲连作模式,连作模式会引起土壤有害物质积累,田间病虫草害频发[1],种植过程中存在过量使用农药化肥,且肥料利用率低[2]的情况,同时冬闲田面积不断增加,将会威胁到我国的粮食安全和农业生态环境[3]。而水旱轮作是一种新型生态农作模式,能较好地应对传统水稻种植模式存在的弊端[4-5],同时还可以提高水稻产量[6-7],降低农作物发病率[8],调节土壤理化性质,遏制土壤酸化[9],提高土壤养分含量[6],增加土壤微生物丰富度和活性,强化土壤呼吸作用[10],已在我国大面积推广。
土壤及稻米Cd污染日益严重,为此,许多学者研究了不同钝化剂对Cd污染土壤的修复效果。近年来,研究石灰、生物炭和羟基磷灰石(hydroxyapatite, HAP)施加到土壤后重金属生物有效性的变化及其对重金属污染土壤的修复效果成为热门。大量研究[11-16]指出,石灰、生物炭和HAP都能提高土壤pH,而pH的提高能增加土壤胶体对Cd的吸附量[17]。张子叶等[18]发现,石灰能提高水稻茎秆中Ca的含量,抑制Cd通过茎秆转移,从而抑制Cd在稻米中的积累;同时石灰还能促进水稻的生长[19]。生物炭则可以通过表面静电吸附、阳离子交换和吸附沉淀等机制吸附重金属[20],降低其生物有效性;还可以促进水稻对营养元素的吸收[21],并减少Cd在稻米中的积累。添加HAP能显著提高土壤对重金属的固定能力[16],减少土壤中交换态Cd的含量,HAP对Cd的固定主要依赖吸附机制[22-23],包括HAP表面上Ca2+与Cd2+的离子交换以及HAP晶格对Cd的吸附;此外,左清青[24]还发现,施加HAP后,土壤微生物种群数量和多样性均有显著提高,且微生物与HAP能产生协同效应,达到改善土壤生态的目的。
目前,水旱轮作的研究主要关注对作物生长及温室气体排放的影响,农田原位钝化修复技术的研究集中于单一种植模式下对土壤Cd短时间的固化效果,而将两者结合起来研究钝化剂对水旱轮作土壤和作物重金属含量的文献相对较少。本研究以降低土壤有效Cd和作物籽粒中的Cd含量为目标,研究了在水旱轮作模式下施加修复剂对土壤理化性质、土壤有效Cd含量、稻米和油菜籽中Cd积累的影响,并分析了其造成影响的原因。
水旱轮作原位钝化削减技术修复土壤镉污染
Remediation of cadmium pollution in soil by in-situ passivation reduction technology of water and drought rotation
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摘要: 为筛选适用于西南地区水旱轮作土壤Cd污染的修复技术,采用水稻-油菜轮作模式和原位钝化实验相结合的方式,比较了施用石灰、生物炭和羟基磷灰石(HAP)3种常见修复剂对土壤基本理化性质、作物产量及籽粒吸收积累镉的影响。结果表明:3种处理均能显著提高土壤pH,与CK相比,使用石灰、生物炭和HAP后,水稻收获期土壤pH分别提高了1.18、0.51和0.91个单位,油菜收获期土壤pH分别提升了0.29、0.81和0.63个单位,但在油菜收获期施用石灰和HAP处理的土壤pH出现明显回落,降幅为0.91个和0.30个单位,施用生物炭处理的土壤pH则进一步提高了0.28个单位;3种处理在水稻收获期均能提高土壤有机质含量,其中生物炭效果最佳;3种处理均能显著降低水稻收获期土壤有效Cd含量,与CK处理相比,分别降低了21.84%、34.08%和20.12%,但在油菜收获期施用石灰和HAP处理的土壤有效Cd含量较相同处理在水稻收获期时有所回升,而生物炭则进一步降低了41.76%;石灰、生物炭和HAP处理对作物产量影响不大,但与CK处理相比,稻米中Cd含量分别降低了30.00%、43.33%和38.00%,油菜籽中Cd含量分别降低了21.00%、53.57%和55.90%,施用生物炭和HAP处理效果较佳。综上所述,生物炭修复水旱轮作模式下农田Cd污染效果最佳。Abstract: The combination of rice-canola rotation model and in-situ passivation experiment was used to screen the Cd pollution remediation technologies in the water and drought rotation soil and crop of the southwest region. This study compared the effects of three common remediation agents: lime, biochar and hydroxyapatite (HAP) on soil basic physical and chemical properties, crop yield, cadmium absorption and accumulation in seed. The results showed that the three treatments with these agents could significantly improve the soil pH. Compared with CK, after the addition of lime, biochar or HAP, the pHs of the remediated soil at rice harvest time raised by 1.18, 0.51 or 0.91 units, respectively. The remediated soil pHs at rape harvest time raised by 0.29, 0.81 or 0.63 units, respectively. However, the pHs of the soil treated with lime and HAP during the rapeseed harvest period showed a significant drops by 0.91 and 0.30 units, respectively, and the pH of the soil treated with biochar further raised by 0.28 units. The three treatments could improve the soil organic matter content at rice harvest time, and the biochar had the best effect. While these treatments could significantly reduce the effective Cd content in the soil at rice harvest time by 21.84%, 34.08% and 20.12%, respectively. Compared with the same treatments during rice harvest period, the effective Cd content in soil treated with lime and HAP during the rapeseed harvest period increased, while the effective Cd content in soil treated with biochar further decreased by 41.76%. Lime, biochar or HAP treatment had slight effect on crop yield, but compared with CK treatment, the Cd contents in rice decreased by 30.00%, 43.33% or 38.00%, and in rapeseed decreased by 21.00%, 53.57% or 55.90%, respectively. The treatment effects of biochar and HAP was better. In summary, biochar treatment had the best effect on Cd pollution remediation in farmland with water and drought rotation mode.
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Key words:
- water and drought rotation /
- cadmium pollution remediation /
- in situ passivation /
- seed /
- soil
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表 1 处理方法及修复剂用量
Table 1. Treatment methods and dosage of remediation agents
处理编号 修复剂种类 修复剂用量/
(kg·hm−2)每个小区修复
剂用量/kg1 无修复剂 — — 2 石灰 1 200 2.52 3 生物炭 4 005 8.41 4 羟基磷灰石 5 655 11.86 表 2 3种处理后作物产量
Table 2. Crop yields after three treatments
kg·hm−2 处理 稻米产量 油菜籽产量 (干质量) CK 12 379±1.40a 2 985±0.41a 石灰 11 534±2.00a 2 982±0.61a 生物炭 11 679±2.18a 2 617±0.94a HAP 11 923±0.69a 2 801±0.59a -
[1] 张晓红, 张娟娟, 王明兆. 江阴市水旱轮作的实践与思考[J]. 上海农业科技, 2011(5): 150-151. doi: 10.3969/j.issn.1001-0106.2011.05.105 [2] 张福锁, 王激清, 张卫峰, 等. 中国主要粮食作物肥料利用率现状与提高途径[J]. 土壤学报, 2008, 45(5): 915-924. doi: 10.3321/j.issn:0564-3929.2008.05.018 [3] 金姝兰, 侯立春, 徐磊. 长江中下游地区耕地复种指数变化与国家粮食安全[J]. 中国农学通报, 2011, 27(17): 208-212. [4] 徐宁, 黄国勤. 稻田轮作对水稻病、虫、草害的影响[J]. 生物灾害科学, 2013(1): 26-30. [5] 孙丹平. 稻田水旱复种轮作对作物生长、资源利用和土壤生态环境的影响[D]. 南昌: 江西农业大学, 2016. [6] 王飞, 李清华, 林诚, 等. 冷浸田水旱轮作对作物生产及土壤特性的影响[J]. 应用生态学报, 2015, 26(5): 1469-1476. [7] 王子芳, 高明, 秦建成, 等. 稻田长期水旱轮作对土壤肥力的影响研究[J]. 西南农业大学学报(自然科学版), 2003, 25(6): 514-521. doi: 10.3969/j.issn.1673-9868.2003.06.012 [8] 王海霞, 殷俊, 凌须美, 等. 水旱轮作对设施番茄生长影响的初探[J]. 农业装备技术, 2011, 37(4): 43-44. doi: 10.3969/j.issn.1671-6337.2011.04.028 [9] 常新刚, 黄国勤, 熊云明, 等. 双季稻与黑麦草水旱轮作的产量和土壤理化性状分析[J]. 耕作与栽培, 2005(4): 16-17. doi: 10.3969/j.issn.1008-2239.2005.04.007 [10] 张立成, 邵继海, 林毅青, 等. 稻-稻-油菜轮作对土壤微生物活性和多样性的影响[J]. 生态环境学报, 2017, 26(2): 204-210. [11] 谢运河, 纪雄辉, 田发祥, 等. 不同Cd污染特征稻田施用钝化剂对水稻吸收积累Cd的影响[J]. 环境工程学报, 2017, 11(2): 1242-1250. doi: 10.12030/j.cjee.201510041 [12] 张振兴, 纪雄辉, 谢运河, 等. 水稻不同生育期施用生石灰对稻米镉含量的影响[J]. 农业环境科学学报, 2016, 35(10): 1867-1872. doi: 10.11654/jaes.2016-0432 [13] 李园星露, 叶长城, 刘玉玲, 等. 生物炭耦合水分管理对稻田土壤As-Cd生物有效性及稻米积累的影响[J]. 农业环境科学学报, 2018, 37(4): 696-704. doi: 10.11654/jaes.2017-1505 [14] 张燕, 铁柏清, 刘孝利, 等. 玉米秸秆生物炭对稻田土壤砷、镉形态的影响[J]. 环境科学学报, 2017, 38(2): 715-721. [15] CUI H B, ZHOU J, ZHAO Q G, et al. Fractions of Cu, Cd, and enzyme activities in a contaminated soil as affected by applications of micro- and nanohydroxyapatite[J]. Journal of Soils and Sediments, 2013, 4(13): 742-752. [16] 陈杰华, 王玉军, 王汉卫, 等. 基于TCLP 法研究纳米羟基磷灰石对污染土壤重金属的固定[J]. 农业环境科学学报, 2009, 28(4): 645-648. doi: 10.3321/j.issn:1672-2043.2009.04.001 [17] 殷飞, 王海娟, 李燕燕, 等. 不同钝化剂对重金属复合污染土壤的修复效应研究[J]. 农业环境科学学报, 2015, 34(3): 438-448. doi: 10.11654/jaes.2015.03.005 [18] 张子叶, 谢运河, 黄伯军, 等. 镉污染稻田水粉调控与石灰耦合的季节性休耕修复效应[J]. 湖南农业科学, 2017, 12(12): 47-51. [19] 杨静, 谭永锋, 肖志强, 等. 不同剂量石灰对酸化稻田土壤养分含量及水稻产量的影响[J]. 安徽农业科学, 2015, 43(36): 175-176. doi: 10.3969/j.issn.0517-6611.2015.36.068 [20] JIANG T Y, JIANG J, XU R K, et al. Adsorption of Pb(Ⅱ)on variable charge soils amended with rice-straw derived biochar[J]. Chemosphere, 2012, 89(3): 249-56. doi: 10.1016/j.chemosphere.2012.04.028 [21] REGMI P, GARCIA M J L, KUMAR S, et al. Removal of copper andcadmium from aqueous solutin using switch grass biochar produced viahydrothermal carbonization process[J]. Journal of Environmental Management, 2012, 109(17): 61-69. [22] 邢金峰, 仓龙, 葛礼强, 等. 纳米羟基磷灰石钝化修复重金属污染土壤的稳定性研究[J]. 农业环境科学学报, 2016, 35(7): 1271-1277. doi: 10.11654/jaes.2016.07.007 [23] ZHANG Z Z, LI M Y, CHEN W, et al. Immobilization of lead and cadmium from aqueous solution and contaminated sediment using nano-hydrox-yapatite[J]. Environmental Pollution, 2010, 158(2): 514-519. doi: 10.1016/j.envpol.2009.08.024 [24] 左清青. 纳米羟基磷灰石对污染土壤镉钝化效应研究[D]. 保定: 河北大学, 2017. [25] 鲁如坤. 土壤农业化学分析方法[M]. 北京: 中国农业科技出版社, 2000. [26] 孙鸣镝. AB-DTPA浸提土壤多元素的适用性分析及其测定四种土壤污染元素环境质量标准初探[D]. 哈尔滨: 东北林业大学, 2014. [27] BOISSON J, RUTTENS A, MENCH M. Evaluation of hydroxyapatite as a metal immobilizing soil additive for the remediation of polluted soils: Part1. Influence of hydroxyapatite on metal exchangeability in soil, plant growth and plant metal accumulation[J]. Environmental Pollution, 1999, 104(2): 225-233. doi: 10.1016/S0269-7491(98)00184-5 [28] HAO R J, ZHONG-PE L I, CHE Y P. Differences in organic mineralization between aerobic and submerged conditions in paddy soils of southern Jiangsu Province, China[J]. Journal of Integrative Agriculture, 2011, 10(9): 1410-1418. [29] 周晓阳, 徐明岗, 周世伟, 等. 长期施肥下我国南方典型农田土壤的酸化特征[J]. 植物营养与肥料学报, 2015, 21(6): 1615-1621. doi: 10.11674/zwyf.2015.0629 [30] CUI L Q, LI L Q, ZHANG A F, et al. Biochar amendment greatly reduces rice Cd uptake in a contaminated paddy soil: A two -year field experiment[J]. BioResources, 2011, 6(3): 2605-2618. [31] YUAN J H, XU R K, ZHANG H. The forms of alkalis in the biochar produced from crop residues at different temperatures[J]. Bioresource Technology, 2011, 102(3): 3488-3497. doi: 10.1016/j.biortech.2010.11.018 [32] 尹带霞. 生物炭对稻田土壤重金属生物有效性的影响与作用机制[D]. 长沙: 湖南师范大学, 2016. [33] 钱翌, 褚兴飞. 纳米羟基磷灰石修复镉铅污染土壤的效果评价[J]. 环境科学与技术, 2011, 34(11): 176-179. doi: 10.3969/j.issn.1003-6504.2011.11.036 [34] 胥焕岩, 彭明生, 刘羽. pH值对羟基磷灰石除镉行为的影响[J]. 矿物岩石地球化学通报, 2004, 23(4): 305-308. doi: 10.3969/j.issn.1007-2802.2004.04.005 [35] 代允超, 吕家珑, 曹莹菲, 等. 石灰和有机质对不同性质镉污染土壤中镉有效性的影响[J]. 农业环境科学学报, 2014, 33(3): 514-519. doi: 10.11654/jaes.2014.03.017 [36] ANGE N, PATRICK S. Role of phosphate in the remediation and reuse of heavy metal polluted wastes and sites[J]. Waste Biomass Valor, 2010, 1(1): 163-174. doi: 10.1007/s12649-009-9006-x [37] 赵中秋, 朱永官, 蔡运龙. 镉在土壤-植物系统中的迁移转化及其影响因素[J]. 生态环境学报, 2005, 14(2): 282-286. doi: 10.3969/j.issn.1674-5906.2005.02.031 [38] 周婷, 周根娣, 和苗苗. 生物炭对土壤重金属吸附机理研究进展[J]. 杭州师范大学学报(自然科学版), 2018, 17(4): 404-410. doi: 10.3969/j.issn.1674-232X.2018.04.012 [39] 张振宇. 生物炭对稻田土壤镉生物有效性的影响研究[D]. 沈阳: 沈阳农业大学, 2013. [40] 方放, 周建斌, 杨继亮. 稻壳炭提取SiO2及制备活性炭联产工艺[J]. 农业工程学报, 2013, 28(23): 184-191. [41] CHEN Z, TIE B, LEI M, et al. Phytoexclusion potential studies of Si fertilization modes on rice cadmium[J]. Environmental Science, 2014, 35(7): 2762-2770. [42] LIU J X, WANG F, SHEN J X, et al. Study of nano-hydroxyapatite adsorption in heavy metals[J]. Advanced Materials Research, 2013, 777: 15-18. doi: 10.4028/www.scientific.net/AMR.777.15