【作者】 李翔；

【导师】 王小治； 张志勇；

【作者基本信息】 扬州大学 ， 环境工程（专业学位）， 2021， 硕士

【摘要】 近年来,农田土壤重金属污染日益严重,影响了农作物正常生长。土壤重金属超标导致农作物过量吸收重金属到体内,通过食物链方式进入到人体内损害人体健康。为从源头保障农产品质量安全,实现农田土壤镉污染的安全利用,通过大田及盆栽试验研究施加天象土壤调理剂(TX)、宁粮土壤调理剂(NL)、生物炭(BC)、石灰(Li)、硅肥(Si)等5种钝化剂对土壤pH、土壤肥力(有机质、营养元素)、Cd有效态含量、Cd不同形态的影响及钝化剂的持久性效果,并探讨钝化剂对不同水稻、小麦品种的产量以及水稻、小麦各器官吸收Cd的影响,进而筛选出降Cd效果较优的钝化剂和籽粒吸收Cd较少的水稻、小麦品种。得到的主要结果如下:(1)稻季试验中,施加钝化剂降低土壤Cd有效态含量,施加TX、NL 土壤调理剂、生物炭、石灰、硅肥处理较对照处理分别降低了 59.4%、29.9%、22.8%、22.4%、54.4%。施加钝化剂降低了土壤Cd不稳定态含量(弱酸提取态和可还原态),增加了Cd稳定态含量(可氧化态和残渣态)。施加不同钝化剂不同程度降低了各水稻品种根、茎和籽粒Cd含量,并提高各水稻品种产量。其中施加TX 土壤调理剂的效果最优,与对照处理相比,其对南粳9108、扬粳103、扬粳805、淮稻5号籽粒中Cd含量分别显著降低了 80.5%、82.8%、65.4%、55.6%,对水稻产量分别提高了 29.2%、9.2%、18.6%、14.2%。(2)麦季试验中,施加钝化剂降低土壤Cd有效态含量,施加TX、NL 土壤调理剂、生物炭、石灰、硅肥处理较对照处理分别降低了 66.8%、48.6%、12.4%、36.4%、70.8%。BCR结果表明施加钝化剂降低土壤Cd的弱酸提取态和可还原态含量,增加可氧化态和残渣态含量。施加钝化剂抑制各小麦品种根部、茎部和籽粒对Cd的吸收同时提高各小麦品种产量。其中硅肥和TX 土壤调理剂效果较优,Si处理对宁麦13、扬辐麦4号、扬麦15、扬麦23和明麦籽粒Cd分别显著降低54.2%、51.5%、58.7%、44.8%、47.1%,对产量分别提高 11.1%、3.5%、7.7%、10.9%、2.4%。(3)稻季施加钝化剂,麦季不施加各处理对提高土壤pH、有机质均有所回落,对降低土壤Cd有效性效果减弱。降低土壤Cd有效性和抑制小麦根部、茎部和籽粒部位Cd积累量效果最优的是Si处理,其次是TX处理。(4)在稻季试验中,只有种植淮稻5号和扬粳805同时配施TX 土壤调理剂处理,籽粒Cd含量分别为0.163 mg/kg、0.147 mg/kg,符合农产品安全质量标准。麦季试验中,种植宁麦13和扬辐麦4号同时配施硅肥或TX 土壤调理剂,籽粒Cd含量较低。推荐淮稻5号和扬粳805这两个水稻品种、宁麦13和扬辐麦4号为适应于苏中地区的重金属低积累水稻、小麦品种,可再结合施用TX土壤调理剂或硅肥在重金属Cd中轻度污染土壤上推广应用。更多还原

【Abstract】 In recent years,heavy metal pollution in farmland soil has become increasingly serious,which has affected the normal growth of crops.Excessive heavy metals in soil lead to excessive absorption of heavy metals into crops,which enter human body through food chain and harm human health.In order to ensure the quality and safety of agricultural products from the source,and realize the safe use of cadmium pollution in farmland soil,the application of tianxiang soil conditioner(TX),ningliang soil conditioner(NL),biochar(BC),lime(Li),silicon fertilizer(Si)and other 5 passivating agents on farmland and indoor potted plants was studied.Effects on soil pH,soil fertility(organic matter,nutrient elements),Cd available state content,different forms of Cd and the persistence effect of inactivators,and explore the effects of inactivators on the yield of different rice and wheat varieties,as well as rice and wheat.According to the influence of Cd absorption by organs,inactivating agents with better Cd-reducing effect and rice and wheat varieties with less Cd absorption by grains were screened out.The main results obtained are as follows:(1)In the rice season experiment,the application of passivation agent reduced the effective content of soil Cd,and the application of TX,NL soil conditioner,biochar,lime,and silicon fertilizer treatments reduced 59.4%,29.9%,22.8%,22.4%,and 22.4%,respectively,compared with the control treatment.54.4%.The application of passivators reduces the soil Cd unstable state content(weak acid extraction state and reducible state),and increases the Cd stable state content(oxidizable state and residue state).Applying different inactivators to varying degrees inhibited the absorption of Cd by the roots,stems and grains of each rice variety and increased the yield of each rice variety.Among them,the application of TX soil conditioner had the best effect.It significantly reduced the Cd content in the grains of Nanjing 9108,Yangjing 103,Yangjing 805,and Huaidao 5 by 80.5%,82.8%,65.4%,and 55.6%,respectively.The yield of rice varieties increased by 29.2%,9.2%,18.6%,and 14.2%respectively.(2)In the wheat season test,the application of passivator to reduce the effective content of soil Cd,the application of TX,NL soil conditioner,biochar,lime,and silicon fertilizer treatments reduced by 66.8%,48.6%,12.4%,36.4%,and 36.4%,respectively,compared with the control treatment.70.8%.The BCR results show that the application of passivation agent reduces the content of weak acid extraction state and reducible state,and increases the content of oxidizable state and residue state.The application of inactivating agents inhibited the absorption of Cd by the roots,stems and grains of various wheat varieties while increasing the yield of each wheat variety.Among them,silicon fertilizer and TX soil conditioner are more effective.Si treatment significantly reduces Cd of Ningmai 13,Yangfumai 4,Yangmai 15,Yangmai 23 and Mingmai grains by 54.2%,51.5%,58.7%,44.8,respectively.%,47.1%,increase the output by 11.1%,3.5%,7.7%,10.9%,2.4%respectively.(3)Applying passivation agent in the rice season and not applying any treatment in the wheat season will increase the soil pH and organic matter,but will reduce the effectiveness of reducing soil Cd.For long-term reduction of soil Cd availability and suppression of Cd accumulation in wheat roots,stems and grains,the best effect is Si treatment,followed by TX treatment.(4)In the rice season experiment,only planting Huaidao 5 and Yangjing 805 combined with TX soil conditioner treatment,the grain Cd content was 0.163 mg/kg and 0.147 mg/kg,which met the safety and quality standards of agricultural products.In the wheat season experiment,when both Ningmai 13 and Yangfumai 4 were combined with silicon fertilizer or TX soil conditioner,the Cd content in the grains was low,but both exceeded the safety and quality standards for agricultural products.Two rice varieties,Huaidao 5 and Yangjing 805,Ningmai 13 and Yangfumai 4 are recommended as low-heavy metal accumulation rice and wheat varieties adapted to the central Jiangsu region,and can be combined with TX soil conditioner or silicon fertilizer.更多还原