有机替代下绿洲棉田土壤特性与微生物多样性

发布时间：2018-05-04 15:09

本文选题：有机替代 + 滴灌棉田　；参考：《石河子大学》2017年硕士论文

【摘要】：【目的】随着“水肥一体化”施肥理念在北疆地区的推广应用,大面积施用水溶性化肥,轻施或不施有机肥的现象异常严峻,加之棉花长期单一连作的栽培模式,致使绿洲棉田土壤耕性与生物活性下降、有机质含量低等问题发生。本论文基于连续4年滴灌连作棉田有机替代,即减氮配施有机肥定位试验,研究了减少常规氮肥用量20%、40%,分别配施3000-6000 kg·hm-2有机肥背景下,土壤物理、化学、酶活性及生物特性的变化,探寻驱动土壤酶活性和微生物多样性变化的环境因子,阐明减氮配施有机肥调控北疆连作棉田土壤生物学性状的机制,以期为构建良好土壤结构、提升耕层肥力及维护连作棉田土壤生态系统服务功能提供技术支撑。根据国家对化肥施用“减量替代”、“提质增效”的方针政策,结合北疆棉花产业滴灌连作、长期单一施用化学氮肥这一背景,建立“因时因需因地制宜”的施肥管理策略。【方法】本研究开展于5年(2011-2015y)大田定位施肥试验的第4年(2014y),探讨了减氮配施普通有机肥或生物有机肥条件下,连作棉田土壤理化特性、酶活性、致病菌及拮抗菌多样性的变化及驱动微生物多样性变化的关键因子。1.通过传统平板培养法,结合土壤酶学及实时荧光定量(q-PCR)手段阐明连作棉田土壤生物性质对不同施肥处理的响应规律。2.运用雷达图综合评价法、聚类分析、主成分PCA分析及冗余RDA分析来系统揭示土壤理化因子与土壤微生物群落结构多样性的关系。【主要结果】1.较单施化肥CF处理,减少化学氮肥用量配施不同比例有机肥提高了田间持水量,增幅为16.5%~33.3%。配施有机肥与CK相比,增加了土壤大团聚体粒级,0.25mm水稳性团聚体在80%CF+OF、60%CF+OF处理分别比CK处理增加7.1%和8.0%;在80%CF+BF、60%CF+BF处理则分别提高8.9%和12.3%。2.有机替代的各处理均提高了土壤氮含量,以高量(6000 kg·hm-2)配施生物有机肥处理最显著(P0.05)。相较CF,配施有机肥各处理的SOC、DOC分别提高了8.1%~22.2%、12.7%~21.4%;80%CF+OF、60%CF+OF、80%CF+BF和60%CF+BF处理的活性有机碳含量比CF分别增加1.7%、5.3%、8.0%和13.5%。各有机肥处理也显著提高了土壤磷、钾含量(P0.05)。3.棉花铃期、吐絮期结果均表明,在滴灌棉田连续4年有机替代施肥后,土壤营养酶活性,如脲酶、蛋白酶、碱性磷酸酶、蔗糖酶、β-葡糖苷酶和芳基硫酸酯酶活性均显著提高(P0.05)。同时,配施有机肥处理明显增加了微生物量碳、氮含量,降低土壤微生物量碳氮比MBC/MBN。两个时期的施肥处理均显著提高土壤基础呼吸(P0.05),相较CK处理,施肥处理的土壤基础呼吸分别增加了23.2%~95.2%和13.7%~40.0%。4.土壤防御酶活性,过氧化氢酶(CAT)、过氧化物酶(POD)、多酚氧化酶(PPO)及荧光素二乙酸酯酶(FDA),在各处理中表现为配施生物有机肥(BF)配施普通有机肥(OF)单施化肥(CF)对照(CK)。平板培养法和q-PCR两种方法所得结果均表明,枯草芽孢杆菌、木霉和假单胞杆菌种群数量在60%CF+BF处理最高;相比OF、CF和CK处理,土壤芽孢杆菌丰度在BF处理,分别增加了4.6%、5.8%和50.0%。此外,生物有机肥替代化肥处理明显降低了土壤镰刀菌和大丽轮枝菌数量。5.在连续4年减氮增碳施肥环境下,土壤团聚体稳定性和土壤生物学特征相互影响。土壤不稳定团粒结构(ELT)与土壤总有机碳(SOC)、基础呼吸表现出显著负相关性(P0.05);SOC和MBC/MBN呈极显著负相关,但与土壤基础呼吸、蔗糖酶呈极显著正相关关系(P0.05)。蒙特卡罗Monte Carlo检验显示,WR0.25的解释量为43.4%(F=12.2,P=0.002),相比PAD、WMD及ELT对不同施肥的响应更敏感。冗余分析结果显示,CK处理与镰刀菌数量为正相关,CF处理和大丽轮枝菌数量为正相关,枯草芽孢杆菌、木霉、假单胞杆菌群落数量和POD,FDA,PPO及CAT活性呈密切正相关。土壤有效磷(AP)和有机碳(SOC)是引起土壤芽孢杆菌、木霉及假单胞杆菌丰度变化的驱动因子。【结论】1.减氮20%、40%,以3000 kg·hm-2或6000 kg·hm-2普通有机肥、生物有机肥替代,相比长期单施化肥,均显著提高了土壤碳、氮、磷和钾等含量。2.滴灌棉田配施有机肥,有效提高土壤基础呼吸、微生物商及营养酶、抗逆酶活性等土壤生物学特性,其效果随有机肥替代量的增加而越发明显,生物有机肥的提升效果优于普通有机肥,棉花铃期和吐絮期两个生育期的结果具有良好的协同性。3.生物有机肥对土壤致病菌,即镰刀菌和大丽轮枝菌有明显抑制作用,土壤容重和p H是影响其丰度变化的主要驱动因子;土壤有效磷、有机碳是引起土壤拮抗菌,即枯草芽孢杆菌、木霉及假单胞杆菌多样性变化的关键因子。在减氮增碳施肥条件下以有机质提升为核心,土壤有机碳、生物学性质及团聚体稳定性紧密相关,土壤结构体和生物学特征得到协同改善。
[Abstract]:[Objective] with the popularization and application of the concept of "integration of water and fertilizer" in Northern Xinjiang, the phenomenon of large area application of water-soluble chemical fertilizer, light or non application of organic manure is very severe, and the long-term single continuous cropping pattern of cotton has resulted in the decline of soil tillage and biological viability and low organic matter content in oasis cotton fields. Based on the organic manure substitution of continuous cropping continuous cropping cotton field for 4 years, that is, nitrogen reduction and application organic fertilizer location test, the changes of soil physical, chemical, enzyme activity and biological characteristics were studied under the background of reducing the amount of conventional nitrogen fertilizer 20%, 40% and applying 3000-6000 kg. Hm-2 organic manure respectively, and the environmental factors that drive the soil enzyme activity and the diversity of microbial diversity were explored. In order to provide technical support for building a good soil structure, raising the fertility of the plough layer and maintaining the service function of the soil ecosystem in continuous cropping cotton fields, the principle and policy of "reducing the quantity for the generation" and "improving the quality and increasing the efficiency" in the north of the country The drip irrigation continuous cropping system in Xinjiang cotton industry, with a long-term single application of chemical nitrogen fertilizer, established the fertilization management strategy. [Methods] the study was carried out for fourth years (2014y) of the 5 year (2011-2015y) field fertilization test (2014y), and the soil soil under the conditions of nitrogen reduction and application of organic manure or bio organic fertilizer was studied. Changes in physicochemical properties, enzyme activities, pathogenic bacteria and antagonistic diversity and key factors driving diversity of microbial diversity.1. through traditional plate culture method, combining soil enzymology and real-time fluorescence quantitative (q-PCR) means to clarify the response of soil biological properties of continuous cropping cotton fields to different fertilization treatments.2. application radar map comprehensive evaluation method, Cluster analysis, principal component PCA analysis and redundant RDA analysis were used to systematically reveal the relationship between soil physical and chemical factors and soil microbial community structure diversity. [main results] 1. compared with single fertilizer CF treatment, reducing the amount of chemical nitrogen fertilizer and applying different proportions of organic manure to increase the field water holding capacity, the increase of the increase of 16.5%~33.3%. combined with organic fertilizer compared with CK, Increased soil aggregate particle size, 0.25mm water stable aggregate in 80%CF+OF, 60%CF+OF treatment increased by 7.1% and 8% compared with CK treatment, respectively, in 80%CF+BF, 60%CF+BF treatment increased 8.9% and 12.3%.2. organic replacement respectively to improve the soil nitrogen content, with high (6000 kg. Hm-2) with biological organic fertilizer treatment most significant (P0.05). Compared with CF, SOC, DOC, 8.1%~22.2%, 12.7%~21.4%; 80%CF+OF, 60%CF+OF, 80%CF+BF and 60%CF+BF respectively increased the content of active organic carbon by 1.7%, 5.3%, 8% and 13.5%. organic manures increased soil phosphorus, potassium content (P0.05) and cotton boll period, and the results of drip irrigation showed that in drip irrigation, the results of drip irrigation were all shown in drip irrigation. After 4 years of organic substitution, the activity of soil nutrient enzyme, such as urease, protease, alkaline phosphatase, invertase, beta glucosidase and aryl sulfonesterase, increased significantly (P0.05). At the same time, the treatment of organic manure increased microbial biomass carbon, nitrogen content, and reduced soil microbial biomass carbon and nitrogen ratio in the two period of two periods. Soil basal respiration (P0.05) was significantly increased by fertilizer treatment. Compared with CK treatment, soil basal respiration was increased by 23.2%~95.2% and 13.7%~40.0%.4., respectively, and catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO) and fluorescein two acetate esterase (FDA), respectively. Machine fertilizer (BF) was matched with common organic fertilizer (OF) single fertilizer (CF) control (CK). The results of two methods of flat culture and q-PCR showed that the population of Bacillus subtilis, Trichoderma and Pseudomonas aeruginosa was the highest in 60%CF+BF; compared with OF, CF and CK, the abundance of Bacillus in soil increased by 4.6%, 5.8% and 50.0%., respectively. Under the environment of 4 years of continuous nitrogen reduction and carbon fertilization, soil aggregate stability and soil biological characteristics were influenced by bio organic fertilizer instead of chemical fertilizer treatment. Soil unstable aggregate structure (ELT) and soil total organic carbon (SOC) and basal respiration showed significant negative correlation (P0.05), S (S); S OC and MBC/MBN had a very significant negative correlation, but had a very significant positive correlation with soil basal respiration and sucrase (P0.05). The Monte Carlo Monte Carlo test showed that WR0.25 was 43.4% (F=12.2, P=0.002), and WMD and ELT were more sensitive to the response to different fertilizers than PAD. CF treatment was positively correlated with the number of Dali clad, Bacillus subtilis, Trichoderma, Pseudomonas aeruginosa communities were closely related to the activity of POD, FDA, PPO and CAT. Soil available phosphorus (AP) and organic carbon (SOC) were the driving factors causing the abundance changes of Bacillus, Trichoderma and Pseudomonas. [Conclusion] 1. reduction of nitrogen was 20%, 40%, and 3000 kg. Hm-2 or 6000 kg / hm-2 common organic manure, bio organic fertilizer replacement, compared with long-term single fertilizer application, significantly increased soil carbon, nitrogen, phosphorus and potassium content.2. drip irrigation with organic fertilizer, effectively improving soil basic respiration, microbial business and nutrient enzyme, anti reverse enzyme activity and other soil biological characteristics, the effect of the organic fertilizer is increased with the increase of organic manure. More obvious, the improvement effect of bio organic fertilizer is better than that of ordinary organic fertilizer. The results of two growth stages in Cotton Boll and spit period have good synergistic effect,.3. biological organic fertilizer has obvious inhibition effect on soil pathogenic bacteria, namely Fusarium and Dahlia, and soil bulk density and P H are the main driving factors affecting its abundance change. Available phosphorus, organic carbon (organic carbon) is the key factor that causes the diversity of Soil Antagonistic Bacteria, Bacillus subtilis, Trichoderma and Pseudomonas. In the condition of nitrogen reduction and carbon fertilization, organic matter is promoted to the core, soil organic carbon, biological properties and aggregate stability are closely related, soil structure and biological characteristics have been improved synergistically.

【学位授予单位】：石河子大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S562;S154

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