本文選題：石灰性土壤　切入點：秸稈還田　出處：《西北農林科技大學》2017年博士論文

【摘要】：Zn作為必需微量營養(yǎng)元素,在人體生長發(fā)育過程中起著重要作用,人體Zn缺乏已受到全世界普遍關注。在土壤-植物-動物(人)連續(xù)系統(tǒng)中,土壤Zn缺乏是導致作物可食部分Zn含量低下,最終導致人體Zn缺乏的重要原因。在我國,小麥作為北方人口的主食,主要分布在北方的石灰性土壤地區(qū),該地區(qū)土壤有效Zn含量多處于Zn潛在缺乏水平(DTPA-Zn含量0.5~1.0 mg kg-1),生產的小麥籽粒Zn營養(yǎng)品質低下,難以滿足人體對Zn的營養(yǎng)需求,進而對該地區(qū)人群的身體健康構成嚴重威脅。因此,提高石灰性土壤Zn有效性,對于改善小麥Zn吸收及小麥籽粒Zn營養(yǎng)品質,最終緩解以小麥為主食人群的Zn缺乏具有重要意義。植物根系對Zn的吸收不僅取決于土壤有效Zn含量的高低,還與Zn在土壤中的擴散遷移能力有關。盡管土施Zn肥是一種有效地提高石灰性土壤有效Zn含量的重要措施,但是其對于Zn在土壤擴散遷移影響甚微,最終導致對小麥Zn吸收及籽粒Zn營養(yǎng)品質的改善效果不佳。研究發(fā)現,新鮮有機物料腐解產生的活性有機碳組分如溶解性有機質能與土壤Zn離子發(fā)生絡合或者螯合作用生成可溶性有機Zn復合物,進而顯著提高土壤Zn的有效性和移動性。農作物秸稈還田作為減少環(huán)境污染、提高能源轉化效率、維持和改善農田土壤質量和生產力的重要措施在我國已得到廣泛應用。然而,關于農作物秸稈降解產生的活性有機碳組分對于石灰性土壤外源Zn有效性和形態(tài)轉化、Zn擴散遷移規(guī)律及其冬小麥Zn吸收和籽粒Zn營養(yǎng)品質的影響,目前鮮有報道。因此,本研究通過4個培養(yǎng)和為期兩年的田間試驗探究了秸稈還田對石灰性土壤有效Zn含量、Zn擴散遷移規(guī)律及形態(tài)轉化、小麥Zn吸收及籽粒Zn生物有效性的影響。主要結果如下:(1)田間填埋培養(yǎng)試驗探究了秸稈還田對石灰性土壤DTPA-Zn含量及外源Zn老化的影響。結果表明,單獨秸稈還田對石灰性土壤有效Zn含量(DTPA-Zn)及土壤Zn各形態(tài)組分沒有產生顯著影響,而單獨施Zn顯著提高土壤DTPA-Zn及各組分Zn含量,其中松結有機態(tài)Zn(Lom-Zn)含量提高了近4倍。與單施Zn肥相比,盡管秸稈還田與Zn肥配施對土壤DTPA-Zn、各形態(tài)Zn及外源Zn肥無效化比率的影響不顯著,但通過微孔擴散模型計算發(fā)現秸稈還田與Zn肥配顯著提高了土壤Zn的表觀擴散系數和老化速率。(2)半擴散池室內模擬試驗研究了秸稈還田和外源施Zn對石灰性土壤Zn擴散遷移的影響。結果表明,單獨秸稈還田不會對石灰性土壤DTPA-Zn擴散遷移產生影響。雖然單施Zn肥顯著提高了土壤DTPA-Zn含量及DTPA-Zn的擴散遷移能力,但在培養(yǎng)45 d里土壤DTPA-Zn主要被限制在離施肥區(qū)15 mm以內,而且整個裝置中外源Zn的DTPA-Zn回收率也不足40%。當秸稈還田和Zn配施時,培養(yǎng)45 d土壤DTPA-Zn的最遠擴散距離可達20 mm,而且整個裝置外源Zn肥的DTPA-Zn回收率提高到了45%。此外,對lom-zn進行分組發(fā)現,秸稈還田配施zn肥較單獨施zn顯著增加了有效性較高的富里酸結合態(tài)zn組分的含量,這可能是導致土壤dtpa-zn擴散遷移能力和外源zn肥dtpa-zn回收率提升的主要原因。(3)室內模擬試驗評價了不同有機質含量的石灰性土壤上外源zn有效性及形態(tài)轉化對秸稈還田的響應。結果表明,375℃高溫處理是一種有效的移除石灰性土壤有機質,但不會對其他土壤性質產生顯著影響的方法。有機質移除75%以后,土壤dtpa-zn含量隨著lom-zn含量的減小而顯著降低,表明石灰性土壤原有有機質決定著石灰性土壤有效zn含量的高低。外源施zn顯著的提高土壤dtpa-zn、lom-zn含量及土壤zn轉移因子,但隨著時間推移提升效果均逐漸降低,這是由于施入石灰性土壤(特別是有機質含量相對較低的土壤)的外源zn隨著時間推移逐漸被碳酸鹽礦物和粘土礦物(蒙脫石)吸附固定進而轉化為無效態(tài)zn。此外,在土施zn條件下,秸稈還田顯著提高了土壤zn轉移因子,降低了zn分配指數,表明秸稈還田促進了土壤無效態(tài)zn向有效態(tài)zn組分的轉化,進而極大地抑制了石灰性土壤上外源zn的無效化過程,這種抑制效果在有機質含量相對較高的土壤上表現更為明顯。(4)田間填埋培養(yǎng)試驗評價了不同有機物料對于石灰性土壤外源zn有效性及形態(tài)轉化的影響。結果表明,在土施zn肥的條件下,外源有機物料添加均可以有效的提高石灰性土壤dtpa-zn、lom-zn含量及土壤zn轉移因子,降低土壤zn分配指數,而且各有機物料表現為雞糞玉米秸稈=生物菌肥黃腐酸。盡管雞糞和生物菌肥改善石灰性土壤外源zn有效性效果較好,但是綜合考慮環(huán)境和經濟效益,農作物秸稈配合土施zn肥仍是提高潛在缺zn石灰性土壤zn有效性的最佳選擇。(5)兩年的冬小麥田間試驗研究了秸稈還田和外源施zn對石灰性土壤zn有效性及冬小麥zn吸收的影響。試驗結果表明,單獨秸稈還田沒有對土壤有效zn、各形態(tài)zn含量及小麥zn吸收量產生影響。單施zn肥土壤dtpa-zn、lom-zn含量及zn轉移因子均提高1倍以上,但小麥zn攜出量僅提高了5%,而且zn肥當季利用率及dtpa-zn轉化率分別低于0.1%和20%。秸稈與zn肥配施土壤dtpa-zn、lom-zn含量及zn轉移因子與單施zn結果相似,但小麥zn攜出量卻提高了10%,zn肥的利用率也提高至0.15%。此外,相關分析表明,土壤dtpa-zn、lom-zn含量及zn轉移因子均與小麥zn攜出量及各部分zn含量呈顯著正相關關系。由此可知,除土壤dtpa-zn含量外,lom-zn含量和土壤zn轉移因子也可以作為評價石灰性土壤zn有效性高低的指標。(6)通過對兩季田間試驗冬小麥籽粒zn營養(yǎng)品質的分析發(fā)現,單獨秸稈還田并沒有對小麥籽粒zn含量及其生物有效性產生影響。單施zn肥和秸稈還田配施zn肥均顯著提高冬小麥籽粒zn含量,其中秸稈還田配施zn處理小麥籽粒zn含量最高可達39.5mgkg-1。采用植酸/zn摩爾比和人體zn吸收量(taz)對小麥籽粒zn生物有效性進行評價發(fā)現,秸稈還田配施zn肥對冬小麥籽粒植酸/zn摩爾比的降幅最大,對小麥籽粒taz的提高效果最好。此外,對小麥籽粒fe和mn分析表明,秸稈還田配施zn肥在改善小麥籽粒Zn營養(yǎng)品質的同時并不會對小麥籽粒Fe和Mn含量及其生物有效性產生影響。綜上所述,本研究可得到如下結論:(1)秸稈還田配合土施Zn肥在改善石灰性土壤有效Zn含量的同時,也顯著的提高有效Zn在土壤中的擴散遷移能力;(2)土壤原有有機質決定著石灰性土壤DTPA-Zn含量的高低,而外源有機物料(包括作物秸稈)可以通過抑制石灰性土壤對外源Zn的吸附固定,從而提高石灰性土壤外源Zn肥的有效性;(3)秸稈還田配合土施Zn肥可以顯著地提高石灰性土壤上冬小麥對Zn的吸收和籽粒Zn含量及其生物有效性。因此,盡管秸稈還田配合土施Zn肥對于小麥籽粒Zn含量的提高作用尚未達到小麥籽粒Zn強化的目標含量,但是在我國秸稈還田大面積推廣應用的大背景下,土施Zn肥在提高石灰性土壤上冬小麥Zn吸收和籽粒Zn營養(yǎng)品質方面仍具有較大潛力。
[Abstract]:Zn as a micronutrient, plays an important role in the process of human growth and development, lack of human Zn has been paid more attention all over the world. In soil - plant - animal (human) in a continuous system, the soil Zn is the lack of crop edible part of Zn content is low, the ultimate cause of human body Zn deficiency. In China, wheat as a staple food in northern population, mainly distributed in calcareous soil in North China, the content of soil Zn in this region at the Zn level (0.5~1.0 potential lack of DTPA-Zn content mg kg-1), the production of Zn in wheat kernel nutritional quality is low, it is difficult to meet the nutritional needs of the human Zn, which poses a serious threat to the the area of the health of the people. Therefore, to improve the effectiveness of Zn in calcareous soil, to improve the Zn uptake of wheat and wheat grain Zn nutritional quality, and ultimately ease eating wheat population Zn deficiency has important significance. Plant root Zn uptake depends not only on the level of soil available Zn content, is also related to Zn diffusion in soil migration. Although soil Zn fertilizer is an effective and important measure to improve the effective content of Zn in calcareous soil, but the soil Zn in the diffusion migration have little effect, resulting in the poor Zn uptake of wheat grain Zn and improve nutritional quality. The study found that organic carbon produced fresh solutions of organic materials such as corrosion of the dissolved organic matter can generate complex or chelation of soluble organic compound Zn with soil Zn ion, and greatly improve the effectiveness of Zn in the soil and crop straw as mobility. To reduce environmental pollution, improve energy conversion efficiency, maintain and improve soil quality and productivity is an important measure in our country has been widely used. However, the crop straw degradation Active organic carbon produced for calcareous soil is effective and exogenous Zn transformation, Zn diffusion and influence of winter wheat Zn Zn uptake and grain nutritional quality, is rarely reported. Therefore, this research through the 4 culture and field experiments for two years of straw on calcareous soil Zn the content of Zn, diffusion and transformation, and affect the validity of the Zn uptake of wheat grain Zn organisms. The main results are as follows: (1) test to study the effect of straw on calcareous soil DTPA-Zn content and exogenous Zn aging training field landfill. The results show that the single straw on calcareous soil available Zn content (DTPA-Zn) and various forms of soil Zn fractions did not produce a significant effect, and the application of Zn alone significantly increased soil DTPA-Zn and the component content of Zn, which loosely combined organic Zn (Lom-Zn) content increased by nearly 4 times and single. Application of Zn fertilizer, although straw and Zn fertilizer on soil DTPA-Zn, influence the morphology of Zn and exogenous Zn fertilizer void ratio is not significant, but through the pore diffusion model, found that straw and Zn fertilizers significantly increased soil Zn apparent diffusion coefficient and the rate of aging. (2) semidiffusion the indoor pool was studied of straw and exogenous Zn diffusion effect on the migration of Zn in calcareous soil. The results showed that straw alone will not spread the influence on the migration of DTPA-Zn in calcareous soil. Although Zn fertilizer significantly increased the content of DTPA-Zn and DTPA-Zn diffusion of soil migration, but in the training of 45 D in soil DTPA-Zn is mainly restricted within from fertilization area 15 mm, DTPA-Zn and Zn in the recovery of the whole device is less than 40%. when the rate of straw and Zn fertilizer, cultivation of 45 d soil DTPA-Zn is the diffusion distance of up to 20 mm, and the The whole device and the DTPA-Zn recovery of exogenous Zn fertilizer rate increased to 45%. in addition, the lom-zn group found that straw fertilizer Zn fertilizer was lower than single Zn application significantly increased the effectiveness of high fulvic acid content of Zn components, which may lead to soil dtpa-zn diffusion main reason and exogenous force Zn fertilizer dtpa-zn recovery rate increased. (3) the indoor simulation test to evaluate the efficacy of exogenous Zn and speciation in response to straw of different organic matter content in calcareous soil. The results show that the high temperature of 375 DEG C treatment is an effective removal of organic matter in calcareous soil, but did not have a significant impact on the other soil properties. The organic matter removal after 75%, dtpa-zn content of soil decreased as the concentration of lom-zn decreased significantly, showed that the calcareous soil original organic matter determines the effective content of Zn in calcareous soil. The level of external source Application of Zn significantly increased soil dtpa-zn, lom-zn content and Zn of soil transfer factor, but as time goes on to enhance the effect of decreased, which is due to the calcareous soil (especially a relatively low organic matter content of soil) exogenous Zn with the passage of time gradually by the salt mineral carbonate and clay mineral adsorption (Meng Tuoshi) fixed and then into invalid state zn. in addition, in soil Zn under the condition of straw returning significantly increased soil Zn transfer factor, reduces the Zn distribution index showed that straw returning promoted soil available to invalid state Zn conversion of Zn components, which greatly inhibited the invalidation process on calcareous soil of exogenous Zn and this inhibitory effect is manifested in relatively high organic matter content of soil is more obvious. (4) the experimental evaluation of different organic materials on calcareous soil of exogenous Zn effectiveness and transformation of training field landfill Effect. The results show that the application of Zn fertilizer in soil under the condition of exogenous organic materials were added can effectively improve the calcareous soil dtpa-zn, lom-zn content and Zn of soil transfer factor, reduce soil Zn distribution index, and the organic materials for chicken manure corn straw = biological fertilizer fulvic acid. While chicken manure and biological fertilizer improved effect of exogenous Zn on calcareous soil is good, but considering the environmental and economic benefits, crop straw with soil fertilizer Zn is still the best choice to improve soil Zn availability potential of Zn. Lack of lime (5) effects of two years of winter wheat were studied between straw and exogenous Zn absorption in Calcareous soil the effectiveness of the Zn and Zn of winter wheat. The results showed that no separate straw on soil available Zn, Zn and Zn in all forms of wheat absorption effect. Zn fertilizer soil dtpa-zn, content of lom-zn and Zn Transfer factor was increased more than 1 times, but the Zn uptake of wheat increased by only 5%, but when the season Zn fertilizer utilization rate and the conversion rate of dtpa-zn and 20%. were less than 0.1% Zn of straw and fertilizer of soil dtpa-zn, lom-zn content and Zn transfer factor and single application of Zn were similar, but the wheat uptake is Zn increased by 10%, the use of Zn fertilizer rate increased to 0.15%. in addition, correlation analysis showed that soil dtpa-zn, lom-zn content and Zn transfer factors are taken out of wheat Zn has a significant positive correlation between the amount and the content of Zn. Therefore, the content of soil dtpa-zn, also can be used to evaluate the efficiency of lime soil Zn and soil Zn content index of lom-zn transfer factor (6). Through the analysis of the two season field experiment of winter wheat Zn nutrition found that straw alone had no effect on Zn content of wheat grain and its bioavailability. Zn fertilizer and straw returning Tian fertilizer Zn fertilizer significantly increased the Zn content of winter wheat, including straw fertilizer treatment Zn Zn content of wheat grain is up to 39.5mgkg-1. by phytic acid mole ratio of /zn and human Zn uptake (TAZ) to evaluate the effectiveness of wheat Zn biological, straw fertilizer by Zn Fertilizer on winter wheat phytic acid molar ratio of /zn grain is the largest, best of wheat grain TAZ increase effect. In addition, show that the Fe and Mn analysis on wheat grain, straw fertilizer Zn fertilizer in improving the nutritional quality of wheat grain Zn also does not have an impact on wheat grain Fe and Mn content and its bioavailability. In summary, in this study, the following conclusions can be obtained: (1) straw application with Zn fertilizer in improving the soil available Zn in calcareous soil at the same time, also improve the effective diffusion of Zn in soil migration; (2) the original soil organic matter was determined in Calcareous The soil DTPA-Zn content, and exogenous organic materials (including crop straw) can be fixed by adsorption of exogenous Zn inhibited the calcareous soil, thereby enhancing the effectiveness of exogenous Zn fertilizer in calcareous soil; (3) the straw with soil Zn fertilizer can significantly improve the calcareous soil of winter wheat on the absorption of Zn and the grain content and bioavailability of Zn. Therefore, although the straw application with Zn fertilizer to improve soil Zn content of wheat grain has not yet reached the target content of wheat grain Zn enhancement, but in the straw in large areas of application in the background, application of Zn fertilizer in soil increased on calcareous soil in winter Zn uptake of wheat and grain nutritional quality, Zn still has great potential.

【學位授予單位】：西北農林科技大學
【學位級別】：博士
【學位授予年份】：2017
【分類號】：S141.4;S512.11
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本文編號：1704121