稻田消解沼液工程措施的水环境风险分析  

Analysis of water environment risk on biogas slurry disposal in paddy field

作　　者：王子臣[1,2] 梁永红[2] 盛婧[1] 管永祥[2] 吴昊[2] 陈留根[1] 郑建初[1] 

机构地区：[1]江苏省农业科学院农业资源与环境研究所,江苏省农业科学院循环农业研究中心,南京210014 [2]江苏省农业环境监测与保护站,南京210036

出　　处：《农业工程学报》2016年第5期213-220,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家科技支撑计划项目(2012BAD14B12);国家水体污染控制与治理科技重大专项(2012ZX07101004);江苏省农业科技自主创新资金项目(CX(14)2106);江苏省农业三新工程项目(SXGC[2015]291)

摘　　要：为研究稻田消解沼液的能力及消解沼液过程中潜在的水体环境污染风险,该文通过田间定位试验,采取工程措施,监测并分析了稻田主要生育期消解沼液过程中田面水及不同深度下渗水总氮、铵态氮和硝态氮质量浓度变化情况。结果表明：1）稻田消解沼液的关键时期是施灌后的前3 d,总氮降解幅度达46.67%～78.36%,铵态氮降解幅度达47.52%～85.27%,且穗肥期消解速率大于基蘖期。施灌后3 d内若产生径流造成周边水体富营养化的环境风险较大,可采取封闭大田排水口或增加小区田埂高度5～10 cm等田间工程措施,控制地表径流产生量和产生时间,确保安全消解,实现农业面源污染源头减量减排。2）沼液消解量在200%BS处理（沼液氮量为常规施肥氮量的2倍,即沼液量705.88 t/hm2）以上,基蘖期和穂肥期对周边水体潜在的污染风险均高于常规施肥处理,100%BS处理（沼液氮量为常规施肥氮量的1倍,即沼液量352.94 t/hm2）与常规施肥处理相比潜在的环境污染风险稍低。因此,稻田工程措施消解沼液应采取少量多次的消解方式。3）稻田工程措施消解沼液对下渗水的污染风险主要集中在基蘖期,以铵态氮污染风险为主,硝态氮污染风险较小,污染程度因下渗水深度不同而有所差异。研究表明基蘖期稻田每次沼液消解量应控制在211.76 t/hm2以内,穗肥期稻田消解沼液能力较强,污染风险较小,单次消解量低于423.53 t/hm2在该试验的一个稻米生长周期内可视为安全的。该研究结果可为稻田沼液安全消解技术及农业面源污染源头减量减排技术提供理论支撑。To study the digestion ability of biogas slurry in paddy field and the potential risk of water environment pollution in the process of digestion, 4 irrigation amounts of biogas slurry treatments and 2 control treatments were designed based on the location test with engineering measures in this study. The treatments included 1000 t/hm2 biogas slurry at base-tiller stage of rice combined with 120 kg/hm2 nitrogen（urea） at panicle stage of rice（BS10）, and 635.29, 423.53, 211.76 t/hm2 biogas slurry at base-tiller stage respectively combined with 423.53, 282.35, 141.18 t/hm2 biogas slurry at panicle stage（300% BS, 200% BS and 100% BS）. The control treatments were conventional fertilization（CF） with 180 kg/hm2 nitrogen（urea） at base-tiller stage and 120 kg/hm2 nitrogen（urea） at panicle stage, and no-fertilization treatment（CK） without fertilizer both at base-tiller stage and at panicle stage of rice. Then the changes of the total nitrogen, ammonia nitrogen and nitrate nitrogen in both field surface water and soil percolation water at 40 and 60 cm depth were monitored 1, 2, 3, 5 and 7 d after biogas slurry application during the main rice growth period. The data were analyzed by Microsoft Excel（2010） and SPSS for windows（13.0）. Results showed that： 1） The key period of biogas slurry digestion in paddy field was the first 3 d after irrigation with the total nitrogen degradation rate of 46.67%-78.36% and the ammonia nitrogen degradation rate of 47.52%-85.27%. And the digestion rate at panicle fertilizer stage was greater than that at base-tillers stage. The environmental risk of surrounding water body eutrophication was bigger if runoff was generated 3 d after the irrigation. To ensure safe disposal and realize the reduction of agricultural non-point source pollution source and emissions, engineering measures should be adopted such as closing field drain or increasing ridge height by 5-10 cm to control surface runoff. 2） The potential risk of surrounding water pollution with the am

关 键 词：环境控制 氮 污染 稻田 水环境风险 沼液 安全消解 地下水 

分 类 号：X713[环境科学与工程—环境工程] S19[农业科学—农业基础科学]