生化抑制剂组合对黄泥田土壤氮素转化的影响及其环境生态效应

发布时间：2018-05-12 02:41

  本文选题：尿素 + 脲酶抑制剂　； 参考：《浙江大学》2017年博士论文

【摘要】：尿素是我国农业生产中广泛应用的氮(N)肥种类,如何减少稻田尿素N损失对提高水稻氮肥利用率、减少环境污染至关重要。从土壤中N素生物化学转化的过程入手,采用脲酶/硝化抑制剂进行双重调控,是从源头上控制农田N素污染、实现高效利用尿素N的有效措施。本文采用室内培养试验研究脲酶抑制剂N-丁基硫代磷酰三胺(NBPT)和硝化抑制剂2-氯-6-(三氯甲基)吡啶(CP)及其两者组合对尿素态N在黄泥田土壤中的转化作用效果及氨(NH3)挥发累积特性的影响,以及土壤温度和含水量互作对生化抑制剂组合抑制N素转化效果的影响;对比土壤或纯脲酶中N-丙基硫代磷酰三胺(NPPT)与NBPT抑制尿素水解效果,评价抑制脲酶性能,并通过分子对接和分子动力学模拟研究其与洋刀豆脲酶的相互作用机制。采用土柱淋溶试验,研究N肥配施生化抑制剂组合对N、钾(K)在黄泥田土体中淋溶损失,及土壤CO2、CH4和N2O累积排放和全球增温潜势(GWP)的影响。采用田间试验研究生化抑制剂组合与施肥模式互作对黄泥田水稻产量、群体质量和养分利用率、稻季田面水和渗漏液N素浓度动态变化、NH3挥发及稻季温室气体(CH4和N2O)排放通量的影响。取得的主要研究结果如下:1.生化抑制剂组合对黄泥田土壤尿素态氮转化及氨挥发累积特性的影响:不同剂量NBPT处理可以缓释尿素施入3～9 d,有效抑制土壤脲酶活性,减缓尿素分解,显著降低NH3挥发速率峰值34.98%。不同剂量CP处理可以有效抑制NH4+-N向NO3--N转化,其有效调控时间长达72 d以上,但加剧NH3的挥发损失,显著增加NH3挥发速率峰值10.89%。NBPT+CP组合既能缓释尿素3～9d,有效抑制脲酶活性,减缓尿素水解,又能保持土壤中较高NH4+-N含量的时间超过72 d,且降低施肥初期的NH3挥发速率,减少NH3挥发损失。在黄泥田土壤中施用生化抑制剂时,NBPT和CP选用范围分别为≤0.5%和≤0.3%。2. NPPT与NBPT的脲酶抑制效应比较:壤土和黏土中,尿素作用时间≤9d,NBPT/NPPT可以延长尿素水解时间超过3d。砂土中,尿素分解过程相对缓慢,NBPT/NPPT显著降低土壤脲酶活性,抑制NH4+-N生成。不同尿素用量条件下,脲酶抑制剂在不同质地土壤中脲酶抑制效果表现为高施N量优于低施N量,且砂土黏土壤土。不同剂量NPPT与土壤或洋刀豆脲酶反应显著抑制脲酶活性,延缓尿素水解,效果与NBPT类似。分子对接显示,NPPT/NBPT与洋刀豆脲酶之间的作用模式相似:两者均渗入脲酶活性催化位点,与洋刀豆脲酶催化部位的镍离子和不同氨基酸的残基密切结合。模拟计算得出,NPPT和NBPT与洋刀豆脲酶的结合能(AGdock)分别为-66.04 kcal·mol-1 和-66.36 kcal·mol-1。NPPT由于其产品热稳定性高、适于尿素融浆的加工过程,有利于尿基肥料应用在以后的生产中。3. 土壤温度和含水量互作对生化抑制剂组合抑制氮素转化效果的影响:土壤温度和土壤含水量对生化抑制剂组合在黄泥田土壤中抑制尿素水解效应显著,以土壤温度影响更大。随着土壤温度增加,尿素水解转化增强,有效作用时间降低,硝化作用增强,脲酶和硝化抑制效应减弱;随着土壤含水量降低,尿素水解转化缓慢,有效作用时间延长,硝化作用减弱,脲酶和硝化抑制效应增强。不同土壤温度和含水量条件下,NBPT/NPPT或配施CP处理有效抑制黄泥田土壤中脲酶活性,延缓尿素水解;CP或配施NBPT/NPPT处理有效抑制NH4+-N向NO3--N转化,保持土壤中较高NH4+-N含量长时间的存在。黄泥田土壤中生化抑制剂组合最佳应用的土壤温度和含水量分别为25℃和60%WHC。4.氮肥配施生化抑制剂组合对黄泥田土壤氮、钾淋溶损失及温室气体排放的影响:不同N肥种类NBPT处理可以有效抑制淋溶液中NH4+-N生成,延缓淋洗出峰时间,减少NH4+-N流失;CP处理可以有效抑制NH4+-N向NO3--N转化,减少NO3--N流失,有效调控时间超过72d; NBPT+CP组合既能保持土壤中较高NH4+-N含量,又能降低淋溶液中NO3--N浓度。与单施NBPT相比,配施CP可以减少黄泥田土壤中NO3-淋溶,增加土壤晶格对K+的吸附,减轻K+淋失风险,有效时间长达72 d。不同种类N肥添加CP延迟并显著降低N2O排放通量峰值。CP或配施NBPT分别减少土壤N2O排放量32.66%和24.72% (尿素)、29.85%和29.44% (尿素硝铵);尿素配施NBPT显著减少N2O排放量10.56%。添加抑制剂有效减少各种N肥的GWP,以NBPT+CP组合降幅最大(24.68%)。5.生化抑制剂组合与施肥模式对黄泥田水稻产量、群体质量、养分累积及利用率的影响:尿素分次施用处理水稻产量和经济效益较一次性施用处理分别显著提高14.2%和14.6%;水稻有效茎蘖数、有效叶面积指数(LAI)、抽穗至成熟期干物质累积和抽穗期SPAD值分别提高0.8%、24.0%、9.3%和1.5%;水稻成熟期N、P、K吸收量分别提高11.0%、0.9%、4.2%; N肥吸收利用率和N肥农学利用率分别显著提高27.5%和70.8%。不同施肥模式下,配施生化抑制剂组合(NBPT/NPPT+CP)显著提高水稻有效茎蘖数及茎蘖成穗率,增大有效LAI,增加抽穗期SPAD值,提高水稻粒叶比,改善源库关系;增加水稻N、P、K吸收量,促进抽穗后干物质生产和N素积累,提高籽粒中的养分分配及N素利用效率。6.生化抑制剂组合与施肥模式对黄泥田稻季田面水和渗漏液氮素动态变化、氨挥发及温室气体排放的影响:尿素分次施用处理稻季NH3挥发净损失率较一次性施用处理显著降低24.6%; CH4和N2O排放总量、GWP及GHGI分别显著降低13.5%、20.7%、14.4%和25.0%。不同施肥模式下,CP显著提高稻季田面水NH4+-N浓度和NH3挥发速率峰值,增加稻田NH3挥发损失量,而NBPT/NPPT或配施CP有效降低田面水NH4+-N和NH3挥发速率峰值,减少稻田NH3挥发损失量;CP显著降低稻季渗漏液N03--N浓度和N2O排放通量峰值,减少稻季CH4和N2O排放总量,而CP或配施NBPT/NPPT有效降低渗漏液NO3--N峰值,减少稻季CH4和N2O排放,降低GWP和GHGI。
[Abstract]:Urea is a kind of nitrogen (N) fertilizer widely used in agricultural production in China. How to reduce the loss of urea N in rice field is very important to improve the nitrogen utilization rate and reduce environmental pollution. Starting with the process of bioconversion of N in the soil, the dual regulation of urease / nitrification inhibitor is used to control the pollution of N in farmland from the source and to achieve high level of pollution. The effective measures for using urea N. In this paper, the effect of urease inhibitor N- butyl thiophen three amine (NBPT) and nitrification inhibitor 2- chlorine -6- (CP) pyridine (CP) and their combination on the urea state N in the yellow mud field soil and the effect of the ammonia (NH3) volatilization accumulation, as well as the soil temperature and the soil temperature are studied in this paper. The effect of water content interaction on the inhibition of N transformation by biochemical inhibitor combinations; the inhibition of urea hydrolysis by N- propyl thiophosphoryl three amine (NPPT) and NBPT in soil or pure urease to inhibit urease performance, and to study the interaction mechanism of the urease with the urease by molecular docking and molecular dynamics simulation. Experiments were conducted to study the effects of N fertilizer and biochemical inhibitor combination on the leaching loss of N, potassium (K) in soil and the soil CO2, CH4 and N2O cumulative emission and global warming potential (GWP). The dynamic changes of N concentration, NH3 volatilization and the effect of greenhouse gas (CH4 and N2O) emission fluxes in the rice season. The main results are as follows: 1. the effects of biochemical inhibitor combination on the transformation of urea nitrogen and the accumulation of ammonia volatilization in the soil of the yellow mud field: different doses of NBPT treatment can release urea into 3~9 D and effectively inhibit soil urea Enzyme activity, slowing down the decomposition of urea, significantly reducing the peak NH3 volatilization rate 34.98%., CP treatment can effectively inhibit the transformation of NH4+-N to NO3--N, its effective regulation time is up to 72 D, but it aggravates the volatilization loss of NH3 and increases the peak value of NH3 volatilization, which can not only release urea 3 ~ 9D, but also effectively inhibit urease activity. Reducing the hydrolysis of urea and keeping the time of high NH4+-N content in the soil more than 72 D, and reducing the NH3 volatilization rate at the early stage of fertilization and reducing the loss of NH3 volatilization. The selection range of NBPT and CP is less than 0.5% and the urease inhibition effect of 0.3%.2. NPPT and NBPT, respectively, in the loam soil and clay, in the loam soil and clay. The action time of the element is less than 9D, and the hydrolysis time of the urea can extend the hydrolysis time of urea to exceed the 3D. sand, the urea decomposition process is relatively slow, the urease activity of the soil is decreased and the NH4+-N formation is inhibited by NBPT/NPPT. The urease inhibitors in different soil conditions show that the urease inhibition effect of urease inhibitors is higher than the low application of N in the soil with high application of N and the sand soil. The reaction of different doses of NPPT to soil or yanagan urease significantly inhibited urease activity and delayed urea hydrolysis. The effect was similar to that of NBPT. Molecular docking showed that the mode of action between NPPT/NBPT and yanagan urease was similar: both were infiltrated into urease active site, and nickel ions and different amino groups in the catalytic site of yanagan urease. The simulation results show that the binding energy of NPPT and NBPT with yanagan urease (AGdock) is -66.04 kcal, mol-1 and -66.36 kcal. Mol-1.NPPT, respectively, because of the high thermal stability of the product, which is suitable for the process of urea melting, which is beneficial to the interaction of the soil temperature and water content in the later production of the urea based fertilizer. The effects of inhibitor combination on nitrogen conversion were inhibited: soil temperature and soil water content inhibited the effect of urea hydrolysis on the combination of biochemical inhibitors in the yellow mud field soil, and the effect of soil temperature was greater. With the increase of soil temperature, the hydrolysis of urea was enhanced, the time of effective action was reduced, nitrification was enhanced, urease and nitrification were increased. The inhibition effect was weakened; with the decrease of soil water content, the conversion of urea hydrolysis was slow, the time of effective action was prolonged, nitrification was weakened, and the inhibition effect of urease and nitrification was enhanced. Under the conditions of different soil temperature and water content, NBPT/NPPT or CP treatment effectively inhibited urease activity in the yellow mud field soil, delayed the urea hydrolysis, CP or the application of NBPT/NPPT. The treatment effectively inhibited the transformation of NH4+-N into NO3--N and kept the high NH4+-N content in the soil for a long time. The soil temperature and water content of the best application of the biochemical inhibitor combination in the yellow mud field soil were 25 and 60%WHC.4., respectively, and the effects of the combination of nitrogen fertilizer and nitrogen fertilizer on the soil nitrogen, potassium leaching loss and greenhouse gas emission in the yellow mud field, respectively. NBPT treatment of different N fertilizers can effectively inhibit the formation of NH4+-N in the leaching solution, postpone the peak time of leaching and reduce the loss of NH4+-N. CP treatment can effectively inhibit the transformation of NH4+-N into NO3--N, reduce the loss of NO3--N, and effectively control the time more than 72d; NBPT+CP combination can not only keep the higher NH4+-N content in the soil, but also reduce the concentration of NO3--N in the leaching solution. Compared with the single application of NBPT, the application of CP could reduce the NO3- leaching in the soil of the yellow mud field, increase the adsorption of the lattice to K+, reduce the risk of K+ leaching, the effective time is 72 D. and the CP delay is added to different kinds of N fertilizers and the N2O emission flux peak.CP or 24.72% (urea), 29.85% and 29.44% (urea), 29.85% and 29.44%, respectively, respectively. (ammonium urea ammonium nitrate); Urea Combined with NBPT significantly reduced N2O emissions by 10.56%. adding inhibitors to effectively reduce GWP of various N fertilizers, and the maximum (24.68%).5. biochemical inhibitor combination and fertilization model on rice yield, population quality, nutrient accumulation and utilization rate in the yellow mud field by NBPT+CP combination: urea applied to rice yield and economy The efficiency of the treatment was increased by 14.2% and 14.6%, respectively, and the effective stem and tiller number, effective leaf area index (LAI), the accumulation of dry matter and the SPAD value of the heading stage were increased by 0.8%, 24%, 9.3% and 1.5%, and the absorption of N, P and K in the mature period of rice was 11%, 0.9%, 4.2%, and N fertilizer utilization and N fertilizer utilization ratio respectively. Under the different fertilization modes of 27.5% and 70.8%., the combination of biochemical inhibitor combination (NBPT/NPPT+CP) significantly increased the number of effective tillers and the percentage of tillers, increased the effective LAI, increased the SPAD value of the heading stage, increased the grain leaf ratio and improved the relationship between the source and reservoir, and increased the absorption of N, P and K in rice, and promoted the production of dry matter after heading and the accumulation of N in the heading. The effects of nutrient distribution and N utilization efficiency on the dynamic changes of nitrogen in rice water and leachate, ammonia volatilization and greenhouse gas emissions from rice water and leachate in yellow mud field were improved by.6. biochemical inhibitor combination and fertilization mode. The loss rate of volatile net volatilization of NH3 was significantly reduced by 24.6% compared with that of one-time application treatment in rice season, and CH4 and N2O emissions were total. Quantity, GWP and GHGI significantly decreased 13.5%, 20.7%, 14.4% and 25.0%., CP significantly increased the concentration of NH4+-N and the peak of NH3 volatilization in rice field, and increased the volatilization loss of NH3 in paddy field, while NBPT/NPPT or combined CP decreased the peak value of NH4+-N and NH3 volatilization rate of paddy field water and reduced the volatilization loss of paddy NH3. The concentration of N03--N and N2O emission flux peak in rice season leachate, decrease the total emission of CH4 and N2O in rice season, and CP or NBPT/NPPT to reduce NO3--N peak in leakage fluid, reduce CH4 and N2O emission in rice season, reduce GWP and GHGI..

【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S153.6
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本文编号：1876787