本文選題：再生水 + 深層土壤��； 參考：《中國(guó)農(nóng)業(yè)大學(xué)》2016年博士論文

【摘要】：再生水灌溉是緩解水資源短缺地區(qū)農(nóng)業(yè)用水壓力的重要舉措,但是再生水中含有相對(duì)較高的鹽分、養(yǎng)分及溶解性有機(jī)質(zhì)(DOM)等,再生水灌溉可能增加深層土壤中鹽分離子的含量和對(duì)地下水的污染風(fēng)險(xiǎn),增強(qiáng)農(nóng)田排放溫室氣體的潛能。本文通過(guò)種植夏玉米/冬小麥田間試驗(yàn),首先研究了不同水氮水平下深層土壤中氮素的遷移特性,以及再生水灌溉下深層土壤中鹽分離子的遷移規(guī)律；然后率定和驗(yàn)證了再生水灌溉下深層土壤中水鹽運(yùn)移參數(shù),構(gòu)建了區(qū)域模擬模型和評(píng)估模型,評(píng)估了再生水長(zhǎng)期灌溉對(duì)地下水的影響；最后借助室內(nèi)培養(yǎng)試驗(yàn),一是探討灌水水質(zhì)類型(地下水、再生水)、添加氮肥類型(K15NO3、(15NH4)2SO4)和不同含水率(40%、60%和90%WFPS)對(duì)土壤N2O排放和氮肥轉(zhuǎn)化的影響機(jī)理,二是研究灌水水質(zhì)類型(地下水、再生水)和氮肥類型(尿素、硫酸銨和緩釋肥)對(duì)土壤碳和氮礦化的影響機(jī)理。獲得以下結(jié)論：(1)在深層壤土土壤中,3種施氮量(142.5、285.0和427.5 kg Nhm-2)和80 mm灌水定額下NO3--N、NH4+-N和TN主要在0～145 cm土層變化,影響深度為440 cm。在深層非均質(zhì)土壤中,土壤質(zhì)地和結(jié)構(gòu)對(duì)水分、NO3--N和TN在土壤剖面中的分布有顯著影響,土壤結(jié)構(gòu)對(duì)NH4+-N在土壤剖面中的分布有顯著影響；4種施氮量(0、130、260和390kgNhm-2)和2種灌水定額(52.5和105 mm)下NO3--N、NH4+-N和TN主要在0～400、0～200和0～120 cm土層變化,影響深度為400 cm,而380～450 cm粘質(zhì)壤土土層對(duì)氮素的遷移起到了阻滯作用。(2)在深層非均質(zhì)土壤中,土壤質(zhì)地和結(jié)構(gòu)顯著影響土壤中鹽分離子的含量。3種灌水處理(地下水灌水定額52.5 mm、再生水灌水定額分別為52.5和105 mm)下Na+、Mg2+、SO42-、 HCO3主要在0～120 cm土層中隨水分遷移和累積,380～450 cm粘質(zhì)壤土土層對(duì)鹽分離子的遷移起到了阻滯作用,減小了對(duì)地下水的污染風(fēng)險(xiǎn)。與地下水相比,相同灌水定額的再生水灌溉使土壤中K+、Ca2+和Cl-含量明顯增加,3種離子遷移能力較強(qiáng),分別主要在0～450、0～250和0～120cm土層變化,而影響深度分別為450、450和380 cm。(3)模擬了田間深層非均質(zhì)土壤中含水率和ECe值,率定和驗(yàn)證了水鹽遷移參數(shù)。構(gòu)建了水鹽遷移區(qū)域模擬模型,結(jié)果表明未來(lái)50年間通州區(qū)和大興區(qū)再生水灌溉包氣帶底端土壤ECe平均值是0.70和0.85 dS m-1,分別是地下水灌溉的1.40和1.09倍。提出了5個(gè)風(fēng)險(xiǎn)指標(biāo),構(gòu)建了區(qū)域評(píng)估模型,發(fā)現(xiàn)通州區(qū)和大興區(qū)再生水灌溉鹽分對(duì)地下水的污染風(fēng)險(xiǎn)分別是地下水灌溉的1.06和1.08倍,而通州區(qū)地下水和再生水灌溉的污染風(fēng)險(xiǎn)分別是大興區(qū)的1.75和1.72倍。長(zhǎng)期再生水灌溉需要同時(shí)考慮再生水中的鹽分含量以及包氣帶結(jié)構(gòu)特性。(4)室內(nèi)原狀土柱添加K15NO3或(15NH4)2SO4并在不同含水率下培養(yǎng)216 h后,不同處理N2O累積排放量為3.78～36.30 mgNm-2,氮肥N2O損失占氮肥總量的0.14%～2.44%,氮肥殘留占氮肥總量的10.16%～26.95%。與地下水相比,再生水灌溉土壤在40% WFPS時(shí)N2O排放量顯著增加了10.98%,在60% WFPS時(shí)氮肥殘留顯著增加了20.95%。灌水水質(zhì)類型和土壤含水率對(duì)氮肥N2O損失具有顯著交互作用,灌水水質(zhì)類型和氮肥類型對(duì)氮肥殘留也具有顯著交互作用,再生水灌溉在特定條件下影響了土壤N2O排放和氮肥轉(zhuǎn)化。氮肥類型和含水率是影響N2O排放量和氮肥轉(zhuǎn)化的2個(gè)重要因素。再生水滴灌時(shí)控制土壤含水率在41%和60% WFPS之間(最佳含水率為45.5% WFPS)并施用KNO3能減少N2O排放和氮肥N2O損失,增加土壤氮肥殘留。(5)室內(nèi)開展了20 d的碳礦化試驗(yàn)和14周的氮礦化試驗(yàn),不同處理碳和氮礦化量的平均值分別為73.50～91.37 mg kg-1和52.65～64.04 mg kg-1。與地下水相比,再生水灌溉處理沒(méi)有顯著增加土壤中DOC、DON、有機(jī)碳和有機(jī)氮的含量,而土壤碳和氮的礦化量分別只增加了3.33%和1.01%。與不施氮肥土壤相比,施尿素、硫酸銨和緩釋肥土壤碳和氮的礦化量分別顯著增加了14.14%-21.22%和15.81%～22.16%；去DOM后土壤碳和氮的礦化量分別顯著降低了9.B3%和14.83%,氮肥和DOM是土壤碳和氮礦化的重要影響因素。(6)綜合考慮地下水和再生水灌溉對(duì)土壤-地下水-溫室氣體的影響效應(yīng),建議北京和其他類似半濕潤(rùn)氣候地區(qū)長(zhǎng)期再生水灌溉時(shí)選擇滴灌灌溉,施用NO3-形態(tài)氮肥,單季施氮量小于150kg N hm-2,并控制土壤含水率在41%和60% WFPS之間。
[Abstract]:Reclaimed water irrigation is an important measure to alleviate the water pressure in agricultural water shortage area, but the reclaimed water contains relatively high salinity, nutrient and dissolved organic matter (DOM). Reclaimed water irrigation may increase the content of salt ions in deep soil and the risk of contamination of groundwater, and enhance the potential of greenhouse gas emission from farmland. In the field of summer maize / winter wheat field experiment, the migration characteristics of nitrogen in deep soil under different water and nitrogen levels and the migration law of salt ions in deep soil under reclaimed water irrigation were studied, and the parameters of water and salt migration in deep soil under reclaimed water irrigation were determined and verified, and a regional simulation model and evaluation were constructed. The model was used to assess the effect of reclaimed water on long-term irrigation on groundwater. Finally, with the help of indoor culture tests, one was to explore the effects of irrigation water quality (groundwater, reclaimed water), nitrogen fertilizer type (K15NO3, (15NH4) 2SO4) and different water content (40%, 60% and 90%WFPS) on soil N2O emission and nitrogen fertilizer transformation, and two to study irrigation water quality. The influence mechanism of type (groundwater, reclaimed water) and nitrogen fertilizer type (urea, ammonium sulfate and slow release fertilizer) on soil carbon and nitrogen mineralization. The following conclusions are obtained: (1) in deep loam soil, 3 kinds of nitrogen application (142.5285.0 and 427.5 kg Nhm-2) and 80 mm irrigation quota are NO3--N, NH4+-N and TN are mainly in the 0~145 cm soil layer, and the influence depth is 440 cm. in the deep loam soil. In deep heterogeneous soil, soil texture and structure have significant influence on the distribution of water, NO3--N and TN in soil profile. Soil structure has a significant influence on the distribution of NH4+-N in soil profile; 4 nitrogen application (0130260 and 390kgNhm-2) and 2 kinds of irrigation quota (52.5 and 105 mm) NO3--N, NH4+-N and TN mainly from 0 to 400,0 to 200 and 0 to 0 ~. 120 cm soil layer change, the influence depth is 400 cm, and the 380~450 cm clay loam soil layer has blocked the nitrogen migration. (2) in the deep heterogeneous soil, the soil texture and structure significantly affect the content of salt ions in the soil.3 irrigation treatment (groundwater irrigation quota 52.5 mm, reclaimed water irrigation quota is 52.5 and 105 mm respectively). Na+, Mg2+, SO42-, HCO3 are mainly migrated and accumulated in the 0~120 cm soil layer with water, and the 380~450 cm clay loam soil layer plays a blocking effect on the migration of salt ions and reduces the risk of pollution to the groundwater. Compared with the groundwater, the same irrigation quota of regenerated water irrigation makes the content of K+, Ca2+ and Cl- significantly increased, 3 kinds of ions in the soil. The migration ability is strong, mainly in 0 ~ 450,0 ~ 250 and 0 ~ 120cm soil layers, and the depth of influence is 450450 and 380 cm. (3) respectively. The water content and ECe value in the deep inhomogeneous soil in the field are simulated. The water and salt migration parameters are determined and verified. The simulation model of water and salt migration is constructed. The results show that Tongzhou District and Daxing are in the next 50 years. The average value of soil ECe at the bottom end of the zone of reclaimed water irrigated by regenerated water is 0.70 and 0.85 dS M-1, 1.40 and 1.09 times of groundwater irrigation, respectively. 5 risk indexes are put forward, and a regional evaluation model is put forward. It is found that the risk of groundwater pollution in Tongzhou District and Daxing District is 1.06 and 1.08 times of groundwater irrigation, while Tongzhou District The pollution risk of groundwater and reclaimed water irrigation is 1.75 and 1.72 times as high as that of Daxing District. Long term reclaimed water irrigation needs to consider the salt content of the regenerated water and the structural characteristics of the cladding zone. (4) K15NO3 or (15NH4) 2SO4 is added to the original soil column and 216 h under different water content, and the cumulative emission of N2O is 3.78 ~ 3 at different treatments. 6.30 mgNm-2, nitrogen fertilizer N2O loss accounted for 0.14% ~ 2.44% of total nitrogen, nitrogen residue accounted for 10.16% ~ 26.95%. of total nitrogen, compared with ground water, the N2O emission of the soil irrigated by reclaimed water was significantly increased by 10.98% at 40% WFPS. At 60% WFPS, the nitrogen residue significantly increased the 20.95%. water quality and the soil moisture content to the N2O loss of nitrogen fertilizer. The irrigation water quality and nitrogen type have significant interaction with nitrogen fertilizer residues. The reclaimed water irrigation affects the soil N2O emission and nitrogen fertilizer conversion under specific conditions. Nitrogen type and water content are 2 important factors affecting N2O emission and nitrogen fertilizer conversion. The soil water content of the regenerated water drip irrigation is 41% and the soil water content is controlled by the reclaimed water drip irrigation. 60% WFPS (the optimum water content is 45.5% WFPS) and KNO3 can reduce N2O emission and nitrogen fertilizer N2O loss and increase soil nitrogen fertilizer residues. (5) 20 d carbon mineralization test and 14 week nitrogen mineralization test have been carried out in the room. The average value of different treatments of carbon and nitrogen mineralization is 73.50 to 91.37 mg kg-1 and 52.65 to 64.04 mg kg-1. and underground water facies, respectively. In contrast, reclaimed water irrigation did not significantly increase the content of DOC, DON, organic carbon and organic nitrogen in soil, while the mineralization of soil carbon and nitrogen increased by 3.33% and 1.01%., respectively, and the mineralization of carbon and nitrogen in urea, ammonium sulphate and slow-release fertilizers increased by 14.14%-21.22% and 15.81% to 22.16%, respectively, and to DO After M, the mineralization of soil carbon and nitrogen was significantly reduced by 9.B3% and 14.83%. Nitrogen and DOM were important factors for the mineralization of soil carbon and nitrogen. (6) the effects of groundwater and reclaimed water irrigation on soil groundwater and greenhouse gases were considered. It was suggested that the drip irrigation should be selected in Beijing and other semi humid regions. Irrigation, applying NO3- form nitrogen fertilizer, single crop nitrogen application amount was less than 150kg N hm-2, and control soil moisture content between 41% and 60% WFPS.
【學(xué)位授予單位】：中國(guó)農(nóng)業(yè)大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類號(hào)】：S153;S274
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本文編號(hào)：1952357