增氧水输入量对土壤肥力特征和棉花根系作用机理研究

with the refined development of drip irrigation technology, aerated irrigation had become the new measures for tapping the productive potential of crops. The domestic and foreign research showed that aerated irrigation could improve soil fertility and increase crop yield. However, the synergistic mechanism of aeration water inputs to soil and crops was not clear, which became the bottleneck of the development of the theory of aerated irrigation technology in the study. The aeration of the irrigation water using ultra micro bubble technology, through the indoor simulation experiment and field experiments, the mechanism of oxygen water inputs to the soil and cotton root, construction of soil water and oxygen migration model, analysis of water oxygen input on soil nutrient, microorganism and enzyme mechanism The mechanism of the effect of oxygen increasing water input on soil nutrients, microbes and enzymes was analyzed, and response mechanism and cotton root morphology function of water aerobics input; to determine the adsorption of dissolved oxygen saturated soil characteristics, the effect of aerated irrigation on soil fertility characteristics, reveal the influence mechanism of oxygen increasing irrigation on cotton root system function provides a strong theoretical and technical support for the application and popularization of oxygen increasing technology under drip irrigation under the film of cotton in Xinjiang.

随着滴灌技术的精细化发展，增氧灌溉已成为一种挖掘作物高产潜力的新措施。国内外研究表明增氧灌溉能够显著提高土壤肥力和增加作物产量,然而增氧水输入量对土壤和作物的增效作用机理尚不明确，成为增氧灌溉理论发展的技术瓶颈。本研究利用超微气泡技术对灌溉水进行增氧，通过室内模拟试验和田间试验，研究增氧水输入量对土壤和棉花根系的作用机理，构建土壤水氧运移模型，分析增氧水输入量对土壤养分、微生物和酶的作用机理，以及棉花根系形态功能对增氧水输入量的响应；确定土壤溶解氧的吸附饱和特征，探明增氧灌溉对土壤肥力特征的影响程度，揭示增氧灌溉对棉花根系功能的影响机制，为新疆棉花膜下滴灌增氧技术应用推广提供有力的理论技术支撑。

本研究针对增氧水输入的关键性问题，开展增氧水输入对土壤氮肥肥力特征的影响和溶解氧输入作用棉花的效果研究。通过初步探明增氧水输入对土壤中溶解氧变化影响，进而开展室内土壤培养试验，研究不同溶解氧浓度的增氧水对壤土和沙土土壤矿化作用和硝化作用的影响，揭示增氧水输入对土壤的供氮能力的作用机制；通过采用水培实验，进一步研究培养水增氧与否对新陆早50、57、64和73号的生物量、培养水溶解氧浓度变化量、叶绿素、抗氧化物酶活性和根系活力的影响；明确了增氧水输入可以改善土壤氧环境，提升土壤肥力，促进棉花生长，进而为提升棉花增产潜力提供了理论指导。.主要研究结论如下:.(1)农田土壤随着深度增加土壤溶解氧逐步降低，并且随着灌溉水的增加土壤溶解氧浓度迅速降低至零，而增氧水输入可以在一定程度上增加灌溉过程中土壤溶解氧浓度，但不会随着增氧浓度增加而快速增加，只能保持在6-8mg∙L-1。.(2)不同浓度的增氧水输入会促进壤土和沙土土壤硝化作用和矿化作用的发生，但随时间的延长各处理净氮矿化速率和硝化速率均呈下降趋势，作用强度会降低；增氧浓度越高，土氮素转化的程度越剧烈。与达到最大消耗速率所用时间的变化趋势相反，4个不同处理中初始消耗速率V0和最大消耗速率Vmax的趋势变化均为RCK<RD1<RD2<RD3，初始消耗速率V0的最大值（8.9501 mg∙kg-1∙d-1），最大消耗速率Vmax的最大值（13.0198 mg∙kg-1∙d-1）和达到最大消耗速率所用时间TVmax的最小值（1.5021 d）均是RD3处理。综合不同处理效应看，以90%增氧供氧曝气增氧处理氮素转化效果最好。.(3)水培棉花培养水充气有助于提高棉花株高、茎粗、根长、地上部分和地下部分干物质质量以及叶面积、叶绿素a含量、叶绿素b含量、总叶绿素，降低抗氧化物酶活性和根系活力。随培养时间的增长，水培棉花单株溶解氧消耗率增加。从不同处理综合效应来看，64-A处理效果最好。