秸轩生物反应堆和堆肥改善微咸水灌溉下设施土壤和黄瓜生长的研究

发布时间：2018-05-15 20:12

本文选题：秸秆生物反应堆 + 堆肥　；参考：《中国农业大学》2016年博士论文

【摘要】：淡水资源紧缺是制约宁夏设施蔬菜产业发展和影响农民增收的突出问题,而采用微咸水灌溉是缓解宁夏农用淡水资源危机的重要途径之一。但是,微咸水灌溉下作物因受土壤盐分胁迫而容易减产。因此,如何缓解作物盐胁迫并提高作物产量是微咸水可持续利用的前提。为了缓解微咸水灌溉引起的作物盐胁迫,本论文探究了微咸水灌溉下表层(0-20cm)土壤增施堆肥、底层(20-40cm)土壤应用秸秆生物反应堆对设施黄瓜土壤环境和作物生长的影响。主要结果如下：(1)与淡水灌溉相比,微咸水灌溉显著降低了根层(0-40cm)土壤含水量,增加了根层Na盐累积并提高了土壤pH,从而限制了土壤中养分的有效性。但是,在微咸水灌溉下,堆肥和秸秆生物反应堆通过增加土壤有机质提升了根层土壤的持水力,改善了土壤孔隙度并增强了Na盐淋洗。此外,这两种土壤改良措施有效地降低了土壤pH并增加了无机氮、有效钾和有效磷含量。(2)与淡水灌溉相比,微咸水灌溉显著减少了根层土壤可培养微生物(特别是细菌)数量,降低了细菌多样性及秋冬茬氨基酸类和胺类碳源利用率；但是,在微咸水灌溉下,堆肥和秸秆生物反应堆有效阻控了上述微生物环境恶化。(3)与淡水灌溉相比,微咸水灌溉显著降低了植株K+/Na+比值,并抑制了作物NPK养分吸收。但是,在微咸水灌溉下,堆肥和秸秆生物反应堆均不同程度地增加了植株K+/Na+比值并促进了养分吸收。此外,秸秆生物反应堆对微咸水灌溉下植株K+/Na+比值增加幅度要显著高于堆肥；堆肥主要促进植株吸收N和K,而秸秆生物反应堆主要促进植株吸收P。(4)与淡水灌溉相比,微咸水灌溉显著降低了秋冬茬叶片胞间CO2浓度、蒸腾速率和净光合速率,并减少了所有种植茬口植株生物量和果实产量。但是,堆肥和秸秆生物反应堆有效阻控了微咸水灌溉对作物生长的不利影响。此外,微咸水灌溉使得前两个种植茬口果实内可溶性固形物、糖等物质含量有所降低,而在后两个种植茬口则升高。(5)在改善土壤环境和作物生长方面,对于多数指标而言,堆肥和秸秆生物反应堆配套措施并没有表现出明显的加和效应。此外,随微咸水灌溉时间增加(连续四茬),三种土壤改良措施对黄瓜生长的缓解作用逐渐减弱。上述结果表明,对于短期(2年4茬)种植而言,土壤增施堆肥和应用秸秆生物反应堆有利于缓解微咸水灌溉引起的作物盐胁迫并维持产量。但是,对实际生产而言,建议从第四茬开始,采用微咸水与淡水轮灌,并配套使用堆肥和秸秆生物反应堆改良措施减少淡水灌溉的次数。
[Abstract]:The shortage of fresh water resources is a prominent problem that restricts the development of facility vegetable industry in Ningxia and affects farmers' income, and the use of brackish water irrigation is one of the important ways to alleviate the crisis of agricultural freshwater resources in Ningxia. However, crops under brackish water irrigation are prone to yield reduction due to soil salt stress. Therefore, how to alleviate crop salt stress and increase crop yield is the premise of sustainable use of brackish water. In order to alleviate crop salt stress caused by brackish water irrigation, this paper investigated the effects of increasing compost application on surface layer (0-20 cm) and straw bioreactor (20 ~ 40 cm) on soil environment and crop growth of cucumber under brackish water irrigation. The main results were as follows: (1) compared with fresh water irrigation, brackish water irrigation significantly reduced the soil moisture content, increased the accumulation of Na salt in the root layer and increased the pH value of the soil, thus limiting the availability of nutrients in the soil. However, under brackish water irrigation, compost and straw bioreactor increased soil organic matter holding capacity, improved soil porosity and enhanced Na salt leaching. In addition, these two soil improvement measures effectively reduced soil pH and increased inorganic nitrogen, available potassium and available phosphorus contents.) compared with fresh water irrigation, brackish water irrigation significantly reduced the number of culturable microbes (especially bacteria) in root soil. The bacterial diversity and the utilization efficiency of amino acids and amines in autumn and winter stubble were decreased, but under brackish water irrigation, compost and straw bioreactor effectively controlled the deterioration of microbial environment. Brackish water irrigation significantly reduced K / Na ratio and inhibited NPK nutrient uptake. However, under brackish water irrigation, both compost and straw bioreactor increased K / Na ratio and nutrient uptake in different degrees. In addition, the K / Na ratio of straw bioreactor was significantly higher than that of compost under brackish water irrigation, and compost mainly promoted uptake of N and K, while straw bioreactor mainly promoted uptake of P.t4) compared with fresh water irrigation. Brackish water irrigation significantly decreased the intercellular CO2 concentration, transpiration rate and net photosynthetic rate of leaves in autumn and winter stubble, and also decreased the biomass and fruit yield of all crop crops. However, composting and straw bioreactor effectively controlled the adverse effects of brackish water irrigation on crop growth. In addition, brackish water irrigation reduced the contents of soluble solids and sugars in the first two crop crops, but increased in the latter two crops. Compost and straw biological reactor supporting measures did not show a significant additive effect. In addition, with the increase of irrigation time of brackish water (four crops in succession), the mitigation effect of three soil improvement measures on cucumber growth was gradually weakened. The results indicated that for short-term (2 years and 4 crop) planting, the application of soil compost and straw bioreactor could alleviate salt stress caused by brackish water irrigation and maintain yield. However, for practical production, it is suggested that the rotation irrigation of brackish water and fresh water should be adopted from the fourth crop, and the improvement measures of compost and straw biological reactor should be used to reduce the frequency of fresh water irrigation.
【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S626;S642.2

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