γ-聚谷氨酸和耐鹽植物聯(lián)合修復(fù)設(shè)施栽培鹽漬化土壤
發(fā)布時(shí)間：2018-09-17 12:31
【摘要】：設(shè)施農(nóng)業(yè)是隨農(nóng)業(yè)現(xiàn)代化和種植結(jié)構(gòu)調(diào)整發(fā)展起來的新型產(chǎn)業(yè),是最具活力的現(xiàn)代化農(nóng)業(yè),也是傳統(tǒng)農(nóng)業(yè)向現(xiàn)代化集約型農(nóng)業(yè)轉(zhuǎn)變的有效方式。近年來我國設(shè)施農(nóng)業(yè)發(fā)展迅猛,2008年設(shè)施栽培面積突破330萬hm2,約占世界設(shè)施農(nóng)業(yè)總面積的85%,其中設(shè)施蔬菜種植面積達(dá)到34.7萬hm2；2010年我國設(shè)施蔬菜總產(chǎn)量超過1.7億噸,占蔬菜總產(chǎn)量的25%。設(shè)施農(nóng)業(yè)生產(chǎn)中大水大肥灌溉、土壤連作障礙經(jīng)常發(fā)生,養(yǎng)分失衡嚴(yán)重,土壤中大量鹽分隨水分蒸發(fā)向上運(yùn)動而聚集在土表,造成土壤板結(jié)和次生鹽漬化等環(huán)境問題,導(dǎo)致農(nóng)產(chǎn)品的產(chǎn)量和質(zhì)量下降。其中,設(shè)施土壤次生鹽漬化問題最為突出。目前,全球次生鹽漬化土壤面積達(dá)到7700萬hm2,占農(nóng)業(yè)土壤面積的30%以上,其中58%的鹽漬土分布在農(nóng)業(yè)灌溉區(qū),并呈現(xiàn)逐年增加的趨勢。土壤次生鹽漬化已成為阻礙我國設(shè)施農(nóng)業(yè)發(fā)展的主要問題,修復(fù)次生鹽漬化土壤是設(shè)施農(nóng)業(yè)生產(chǎn)中亟待解決的環(huán)境問題。引起設(shè)施土壤次生鹽漬化的原因很多,主要有環(huán)境因素、盲目施肥、不合理灌溉和種植方式等。次生鹽漬化的發(fā)生不僅造成設(shè)施土壤營養(yǎng)失衡,肥力下降,還會阻礙植物的吸水過程,對作物產(chǎn)生毒害作用,導(dǎo)致作物的產(chǎn)量和品質(zhì)下降；次生鹽漬化還會影響土壤微生物的生長和群落結(jié)構(gòu),抑制微生物活性。目前,鹽漬化土壤的改良和修復(fù)手段主要有工程措施、化學(xué)措施、生物措施和農(nóng)業(yè)措施,雖然取得了一定成效,但還存在建設(shè)投資大、運(yùn)行成本高、容易造成二次污染、修復(fù)效果差或人為影響大等問題,特別是單一措施的修復(fù)能力非常有限,必須將多種修復(fù)手段相結(jié)合。耐鹽植物包括稀鹽植物(或真鹽生植物)、泌鹽植物和拒鹽植物(或假鹽生植物)等,具有良好的脫鹽能力,有關(guān)它們的篩選、開發(fā)與利用引起了學(xué)術(shù)界的關(guān)注。稀鹽植物田菁被廣泛用于修復(fù)鹽漬土,景天三七是新近發(fā)現(xiàn)的一種稀鹽植物,它們不僅對Na+、K+、Ca2+、Mg2+、Cl-和NO3-等鹽分離子具有一定的耐受能力,還能有效吸收這些離子。另一方面,γ-聚谷氨酸(γ-PGA)具有良好的水溶性、超強(qiáng)的螯合能力、生物降解性和環(huán)境友好等特點(diǎn),已被用于廢水中金屬離子的去除研究,但在污染土壤修復(fù)中的應(yīng)用還鮮見報(bào)道。本研究調(diào)查和分析了上海市郊主要園藝場出現(xiàn)耕作障礙的設(shè)施大棚土壤的鹽分特征和鹽漬化程度,應(yīng)用統(tǒng)計(jì)分析方法,確定該地區(qū)次生鹽漬化土壤的主要類型和主要鹽分離子；針對該地區(qū)廣泛分布的Ca2+-Mg2+-NO3型次生鹽漬化土壤,利用γ-PGA螯合土壤中的Ca2+、Mg2+,降低其生物有效性；采用盆栽實(shí)驗(yàn),研究景天三七和田菁對鹽漬土中Ca2+、Mg2+和NO3-的吸收特征；將γ-PGA與耐鹽植物聯(lián)用,去除鹽漬土中的Ca2+、Mg2+和NO3-,考察它們對次生鹽漬土的修復(fù)效果。取得如下主要研究結(jié)果：1.隨著種植年限的增加,上海市郊耕作障礙設(shè)施大棚土壤的平均含鹽量呈現(xiàn)先升高后降低的趨勢,非鹽漬土、微鹽漬土、輕度鹽漬土、中度鹽漬土、重度鹽漬土和鹽土分別占4.35%、17.39%、56.52%、4.35%、4,35%和13.04%。大棚鹽漬土中含鹽量與陰陽離子含量間的相關(guān)性較好,陽離子以Ca2+和Na+為主,其次為Mg2+；陰離子以NO3-和8042-為主,其次為Cl-, NO3是最主要的積累離子。施肥方式、種植年限、作物類型和管理水平都會影響次生鹽漬化程度。根據(jù)典型對應(yīng)分析(CCA),Ca2+、Mg2+和N03-積累量均隨種植年限的增加而增大；長期單施有機(jī)肥或化肥,分別造成土壤堿化或酸化,加重土壤次生鹽漬化；合理混施化肥和有機(jī)肥的大棚土壤鹽漬化程度較低,且不受種植年限的影響。2.根據(jù)鹽分離子和采樣點(diǎn)的關(guān)系,將上海市郊設(shè)施鹽漬化土壤劃分為4種類型：Ⅰ號類型為崇明縣的部分大棚土壤,受Na+、Cl和HCO3-的影響較大；Ⅱ號類型為崇明縣的另一部分大棚土壤,受K+、Ca2+、Mg2+和NO3-的影響較大；Ⅲ號類型包括奉賢、閔行、青浦、部分南匯和部分嘉定地區(qū)的大棚土壤,主要受Ca2+Mg2+、N03和Cl-的影響；Ⅳ號類型為松江、部分南匯和部分嘉定地區(qū)的大棚土壤,主要受SO42-的影響。其中,大部分鹽漬化土壤屬于Ⅲ號類型,應(yīng)重點(diǎn)控制。3.獲得γ-PGA去除Ca2+、Mg2+的最佳條件,即γ-PGA的初始濃度為1000mg.L-1,混合體系的初始pH為7,溫度為25℃在最佳實(shí)驗(yàn)條件下,γ-PGA對Ca2+、Mg2+的最大去除率分別達(dá)到51.59%和68.03%。二級動力學(xué)模型能夠很好地描述γ-PGA對Ca2+、Mg2+的去除過程,獲得Ca2+、Mg2+的去除速率常數(shù)分別為0.00282和0.0166(mg·L1)·1.min-1,其主要作用機(jī)制為γ-PGA的酰胺鍵和羧酸陰離子與Ca2+、Mg2+形成螯合物。4.景天三七對Ca2+、Mg2+_的最大去除率分別為64.35%和53.35%,對NO3也有較強(qiáng)的去除能力,最大去除率為51.78%；田菁對Ca2+、Mg2+的最大去除率分別為82.87%和45.55%。但是,田菁的根瘤菌具有固氮作用以及田菁?xì)報(bào)w的分解作用,使得土壤中N03-濃度維持在1.038 g.kg-1,比原鹽漬土的N03-濃度提高了26.02%。5.盆栽實(shí)驗(yàn)發(fā)現(xiàn),施入y-PGA不僅降低了Ca2+、Mg2+的生物有效性,減小了耐鹽植物幼苗受到的鹽分脅迫,還能促進(jìn)植物的生長發(fā)育和抗逆性。監(jiān)測耐鹽植物的生理參數(shù)發(fā)現(xiàn),1000mg·L-1γ-PGA和景天三七(J3)對Ca2+、Mg2+和N03。的處理效果最好,最大去除率分別達(dá)到93.25%、94.79%和84.26%；200 mg.L-1y-PGA和田菁(T1)對Ca2+、Mg2+的處理效果較好,最大去除率分別達(dá)到90.26%和69.92%。由于田菁根瘤菌的固氮作用和植物殘?bào)w的分解作用,使得土壤中NO3。濃度維持在0.868 g-kg-1,比原鹽漬土的NO3-濃度提高了5.36%。比較y-PGA、耐鹽植物單一處理和聯(lián)合處理的修復(fù)效果,獲得修復(fù)Ca2+-Mg2+-NO3-型次生鹽漬土的最佳組合為1000 mg·L-1 γ-PGA和景天三七(J3),總鹽分的最終去除率達(dá)到74.71%。
[Abstract]:Facility agriculture is a new industry developed with the modernization of agriculture and the adjustment of planting structure. It is the most vigorous modern agriculture and an effective way to transform traditional agriculture into modern intensive agriculture. In 2010, the total yield of protected vegetables exceeded 170 million tons, accounting for 25% of the total yield of vegetables. In protected agricultural production, irrigation with large amount of water and fertilizer, soil continuous cropping obstacles often occur, nutrient imbalance is serious, a large amount of salt in the soil accumulated on the soil surface with the upward movement of water evaporation, resulting in soil erosion. Environmental problems such as soil compaction and secondary salinization have led to a decline in the yield and quality of agricultural products. Among them, secondary salinization of protected soils is the most prominent. At present, the area of secondary salinized soils in the world reaches 77 million hm2, accounting for more than 30% of the total agricultural soil area, of which 58% of the saline soils are distributed in agricultural irrigated areas, showing an increase year by year. Secondary salinization of soil has become a major obstacle to the development of facility agriculture in China. Rehabilitation of secondary salinized soil is an urgent environmental problem in facility agriculture. There are many reasons for secondary salinization of facility soil, such as environmental factors, blind fertilization, irrational irrigation and planting methods. The occurrence of salinization will not only cause the imbalance of soil nutrients and fertility, but also hinder the process of plant water uptake and produce toxic effects on crops, resulting in the decline of crop yield and quality. Secondary salinization will also affect the growth of soil microorganisms and community structure, inhibit microbial activity. There are engineering measures, chemical measures, biological measures and agricultural measures, although some results have been achieved, but there are still many problems, such as large investment in construction, high operating costs, easy to cause secondary pollution, poor repair effect or human impact, especially the repair capacity of a single measure is very limited, and a variety of restoration methods must be combined. Salt-tolerant plants, such as dilute salt plants (or euhalophytes), salt-secreting plants and salt-repellent plants (or pseudohalophytes), have good desalination capacity, and their screening, development and utilization have attracted academic attention. On the other hand, gamma-polyglutamic acid (gamma-PGA) has good water-solubility, strong chelating ability, biodegradability and environmental friendliness. It has been used in the removal of metal ions from wastewater, but in the remediation of contaminated soil. This study investigated and analyzed the salinity characteristics and salinization degree of greenhouse soils with farming obstacles in main horticultural farms in Shanghai suburbs. The main types and main salt segregators of secondary salinized soils in this area were determined by statistical analysis method. The bioavailability of raw saline soil was reduced by chelating Ca 2+, Mg 2+, with gamma-PGA; the absorption characteristics of Ca 2+, Mg 2+ and NO3 - by Sesbania Sesbania and Selaginella paniculata in saline soil were studied by pot experiment; and the effects of removing Ca 2+, Mg 2+ and NO3-, by combining gamma-PGA with Salt-Tolerant plants, on the restoration of secondary saline soil were investigated. The main results are as follows: 1. With the increase of planting years, the average salinity of greenhouse soil in the suburb of Shanghai increased first and then decreased. Non-saline soil, slightly saline soil, slightly saline soil, moderately saline soil, severely saline soil and saline soil accounted for 4.35%, 17.39%, 56.52%, 4.35%, 4,35% and 13.04% respectively. There was a good correlation between soil salt content and anion and cation content. Ca2+ and Na + were the main cations, followed by Mg2 +; NO3 - and 8042 - were the main anions, followed by Cl -, NO3 was the main accumulation ion. Fertilizing methods, planting years, crop types and management level all affected the degree of secondary salinization. +, Mg2+ and N03-accumulation increased with the increase of planting years; long-term application of organic fertilizer or chemical fertilizer resulted in soil alkalization or acidification, which aggravated soil secondary salinization; reasonable mixing of chemical fertilizer and organic fertilizer in greenhouse soil salinization degree is low, and is not affected by planting years. 2. According to the relationship between salt separator and sampling points, the salinization degree will be lower. The greenhouse soils in Shanghai suburbs can be divided into four types: part of the greenhouse soils in Chongming County are of type I, which are greatly affected by Na +, Cl and HCO3 - and part of the greenhouse soils in Chongming County are of type II, which are greatly affected by K +, Ca 2 +, Mg 2 + and NO3 - respectively; part of the greenhouse soils in Fengxian, Minhang, Qingpu, Nanhui and part of Jiading are of type III. The greenhouse soils in this area are mainly affected by Ca2+Mg2+, N03 and Cl-, and the type IV is Songjiang, some Nanhui and some Jiading areas are mainly affected by SO42-. Most of the saline soils belong to the type III and should be controlled emphatically. 3. The optimum conditions for removing Ca2+, Mg2+ by gamma-PGA, i.e. the initial concentration of gamma-PGA is 1000mg.L. The maximum removal rates of Ca2+ and Mg2+ by gamma-PGA were 51.59% and 68.03% respectively under the optimum experimental conditions. The second-order kinetic model could well describe the removal process of Ca2+ and Mg2+ by gamma-PGA, and the removal rate constants of Ca2+ and Mg2+ were 0.00282 and 0.0166 (mg.L1). 1.min-1, respectively. The mechanism of action is that the amide bond of gamma-PGA and the anion of carboxylic acid form chelate with Ca 2+, Mg 2+. 4. The maximum removal rates of Ca 2+, Mg 2+, and NO 3 are 64.35% and 53.35% respectively, and 51.78% respectively, and 82.87% and 45.55% for Ca 2+, Mg 2+ respectively. Nitrogen fixation and Sesbania residue decomposition kept the concentration of N03-in the soil at 1.038 g.kg-1, which was 26.02% higher than that of the original saline soil. 5. Pot experiments showed that the application of y-PGA not only reduced the bioavailability of Ca2+, Mg2+, but also reduced the salt stress on salt-tolerant plant seedlings, and promoted plant growth and development. Monitoring physiological parameters of salt-tolerant plants showed that 1000 mg L-1 gamma-PGA and Sesbania notoginseng (J3) had the best effect on Ca2 +, Mg2 + and N03. The maximum removal rates were 93.25%, 94.79% and 84.26% respectively; 200 mg L-1y-PGA and Sesbania (T1) had the best effect on Ca2 +, Mg2 + with the maximum removal rates of 90.26% and 69.92% respectively. Nitrogen fixation by rhizobia and decomposition of plant residues resulted in the concentration of NO3 in soil being maintained at 0.868 g-kg-1, which was 5.36% higher than that of the original saline soil. Compared with y-PGA, the best combination of single treatment and combined treatment of salt-tolerant plants was 1000 mg-L-1 gamma-PGA and landscape treatment. 37 (J3), the final removal rate of total salt reached 74.71%.
【學(xué)位授予單位】：西南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：S156.41
本文編號：2245930
[Abstract]:Facility agriculture is a new industry developed with the modernization of agriculture and the adjustment of planting structure. It is the most vigorous modern agriculture and an effective way to transform traditional agriculture into modern intensive agriculture. In 2010, the total yield of protected vegetables exceeded 170 million tons, accounting for 25% of the total yield of vegetables. In protected agricultural production, irrigation with large amount of water and fertilizer, soil continuous cropping obstacles often occur, nutrient imbalance is serious, a large amount of salt in the soil accumulated on the soil surface with the upward movement of water evaporation, resulting in soil erosion. Environmental problems such as soil compaction and secondary salinization have led to a decline in the yield and quality of agricultural products. Among them, secondary salinization of protected soils is the most prominent. At present, the area of secondary salinized soils in the world reaches 77 million hm2, accounting for more than 30% of the total agricultural soil area, of which 58% of the saline soils are distributed in agricultural irrigated areas, showing an increase year by year. Secondary salinization of soil has become a major obstacle to the development of facility agriculture in China. Rehabilitation of secondary salinized soil is an urgent environmental problem in facility agriculture. There are many reasons for secondary salinization of facility soil, such as environmental factors, blind fertilization, irrational irrigation and planting methods. The occurrence of salinization will not only cause the imbalance of soil nutrients and fertility, but also hinder the process of plant water uptake and produce toxic effects on crops, resulting in the decline of crop yield and quality. Secondary salinization will also affect the growth of soil microorganisms and community structure, inhibit microbial activity. There are engineering measures, chemical measures, biological measures and agricultural measures, although some results have been achieved, but there are still many problems, such as large investment in construction, high operating costs, easy to cause secondary pollution, poor repair effect or human impact, especially the repair capacity of a single measure is very limited, and a variety of restoration methods must be combined. Salt-tolerant plants, such as dilute salt plants (or euhalophytes), salt-secreting plants and salt-repellent plants (or pseudohalophytes), have good desalination capacity, and their screening, development and utilization have attracted academic attention. On the other hand, gamma-polyglutamic acid (gamma-PGA) has good water-solubility, strong chelating ability, biodegradability and environmental friendliness. It has been used in the removal of metal ions from wastewater, but in the remediation of contaminated soil. This study investigated and analyzed the salinity characteristics and salinization degree of greenhouse soils with farming obstacles in main horticultural farms in Shanghai suburbs. The main types and main salt segregators of secondary salinized soils in this area were determined by statistical analysis method. The bioavailability of raw saline soil was reduced by chelating Ca 2+, Mg 2+, with gamma-PGA; the absorption characteristics of Ca 2+, Mg 2+ and NO3 - by Sesbania Sesbania and Selaginella paniculata in saline soil were studied by pot experiment; and the effects of removing Ca 2+, Mg 2+ and NO3-, by combining gamma-PGA with Salt-Tolerant plants, on the restoration of secondary saline soil were investigated. The main results are as follows: 1. With the increase of planting years, the average salinity of greenhouse soil in the suburb of Shanghai increased first and then decreased. Non-saline soil, slightly saline soil, slightly saline soil, moderately saline soil, severely saline soil and saline soil accounted for 4.35%, 17.39%, 56.52%, 4.35%, 4,35% and 13.04% respectively. There was a good correlation between soil salt content and anion and cation content. Ca2+ and Na + were the main cations, followed by Mg2 +; NO3 - and 8042 - were the main anions, followed by Cl -, NO3 was the main accumulation ion. Fertilizing methods, planting years, crop types and management level all affected the degree of secondary salinization. +, Mg2+ and N03-accumulation increased with the increase of planting years; long-term application of organic fertilizer or chemical fertilizer resulted in soil alkalization or acidification, which aggravated soil secondary salinization; reasonable mixing of chemical fertilizer and organic fertilizer in greenhouse soil salinization degree is low, and is not affected by planting years. 2. According to the relationship between salt separator and sampling points, the salinization degree will be lower. The greenhouse soils in Shanghai suburbs can be divided into four types: part of the greenhouse soils in Chongming County are of type I, which are greatly affected by Na +, Cl and HCO3 - and part of the greenhouse soils in Chongming County are of type II, which are greatly affected by K +, Ca 2 +, Mg 2 + and NO3 - respectively; part of the greenhouse soils in Fengxian, Minhang, Qingpu, Nanhui and part of Jiading are of type III. The greenhouse soils in this area are mainly affected by Ca2+Mg2+, N03 and Cl-, and the type IV is Songjiang, some Nanhui and some Jiading areas are mainly affected by SO42-. Most of the saline soils belong to the type III and should be controlled emphatically. 3. The optimum conditions for removing Ca2+, Mg2+ by gamma-PGA, i.e. the initial concentration of gamma-PGA is 1000mg.L. The maximum removal rates of Ca2+ and Mg2+ by gamma-PGA were 51.59% and 68.03% respectively under the optimum experimental conditions. The second-order kinetic model could well describe the removal process of Ca2+ and Mg2+ by gamma-PGA, and the removal rate constants of Ca2+ and Mg2+ were 0.00282 and 0.0166 (mg.L1). 1.min-1, respectively. The mechanism of action is that the amide bond of gamma-PGA and the anion of carboxylic acid form chelate with Ca 2+, Mg 2+. 4. The maximum removal rates of Ca 2+, Mg 2+, and NO 3 are 64.35% and 53.35% respectively, and 51.78% respectively, and 82.87% and 45.55% for Ca 2+, Mg 2+ respectively. Nitrogen fixation and Sesbania residue decomposition kept the concentration of N03-in the soil at 1.038 g.kg-1, which was 26.02% higher than that of the original saline soil. 5. Pot experiments showed that the application of y-PGA not only reduced the bioavailability of Ca2+, Mg2+, but also reduced the salt stress on salt-tolerant plant seedlings, and promoted plant growth and development. Monitoring physiological parameters of salt-tolerant plants showed that 1000 mg L-1 gamma-PGA and Sesbania notoginseng (J3) had the best effect on Ca2 +, Mg2 + and N03. The maximum removal rates were 93.25%, 94.79% and 84.26% respectively; 200 mg L-1y-PGA and Sesbania (T1) had the best effect on Ca2 +, Mg2 + with the maximum removal rates of 90.26% and 69.92% respectively. Nitrogen fixation by rhizobia and decomposition of plant residues resulted in the concentration of NO3 in soil being maintained at 0.868 g-kg-1, which was 5.36% higher than that of the original saline soil. Compared with y-PGA, the best combination of single treatment and combined treatment of salt-tolerant plants was 1000 mg-L-1 gamma-PGA and landscape treatment. 37 (J3), the final removal rate of total salt reached 74.71%.
【學(xué)位授予單位】：西南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：S156.41
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 李思亮,劉叢強(qiáng),肖化云;地表環(huán)境氮循環(huán)過程中微生物作用及同位素分餾研究綜述[J];地質(zhì)地球化學(xué);2002年04期
2 張玉龍,張繼寧,張恒明,楊麗娟;保護(hù)地蔬菜栽培不同灌水方法對表層土壤鹽分含量的影響[J];灌溉排水學(xué)報(bào);2003年01期
3 王家明;魏玉西;殷邦忠;劉蕾;劉淇;;以牡蠣殼為鈣源的谷氨酸螯合鈣制備工藝研究[J];中國海洋藥物;2010年02期
4 楊景成,韓興國,黃建輝,潘慶民;土壤有機(jī)質(zhì)對農(nóng)田管理措施的動態(tài)響應(yīng)[J];生態(tài)學(xué)報(bào);2003年04期
5 ;Salinity and Persistent Toxic Substances in Soils from Shanghai,China[J];Pedosphere;2009年06期
6 李文慶,張民,李海峰,昝林生;大棚土壤硝酸鹽狀況研究[J];土壤學(xué)報(bào);2002年02期
7 張俊華;賈科利;;寧夏紅寺堡揚(yáng)黃灌區(qū)次生鹽漬化土壤改良成效研究[J];土壤;2011年04期
8 李文慶，駱洪義，丁方軍，劉加芬;大棚栽培后土壤鹽分的變化[J];土壤;1995年04期
9 張北贏;陳天林;王兵;;長期施用化肥對土壤質(zhì)量的影響[J];中國農(nóng)學(xué)通報(bào);2010年11期
10 趙振勇;張科;王雷;王平;田長彥;;鹽生植物對重鹽漬土脫鹽效果[J];中國沙漠;2013年05期
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