施用腐殖酸对土壤一维入渗和蒸发的影响试验研究

发布时间：2019-05-06 13:22

【摘要】：腐殖酸是一种高分子有机物,用于农业生产可改良土壤,还具有节水、省肥、增产和环保等优点。文章通过室内试验研究、结合数值计算和理论分析的方法,开展施用腐殖酸对土壤入渗和蒸发影响的试验研究,对发展农业节水和水肥高效利用具有重要意义。本文主要研究结论如下:(1)为了研究腐殖酸溶液的入渗特性,采用正交设计方法安排了 16组正交试验方案,开展了腐殖酸溶液一维垂直入渗试验。用Phillip模型拟合了累积入渗量与入渗时间的关系,相关性较好。稳渗阶段的腐殖酸溶液的入渗速率及湿润锋运移速率均小于清水入渗试验。分别建立了累积入渗量和湿润锋的多因素计算模型,经验证该模型相关性较好。腐殖酸溶液浓度、土壤容重和土壤初始含水率对累积入渗量和湿润锋运移距离的影响依次减弱,且均呈负相关。分析了不同腐殖酸溶液的减渗效应,发现累积入渗量的减渗率和湿润锋的减少率均与腐殖酸溶液浓度之间呈正相关。入渗结束后,土壤水分分布表明:腐殖酸溶液入渗方案入渗结束后的土壤含水率低于清水入渗试验。(2)为了研究表施腐殖酸条件下的清水入渗特性,采用均匀设计方法安排了 12组试验方案,开展了表施腐殖酸条件下清水一维垂直入渗试验。发现对累积入渗量的实测值采用Phillip模型拟合效果较理想。稳渗阶段,表施腐殖酸各方案的入渗速率和湿润锋运移速率均小于未表施腐殖酸的对照试验方案。分别建立了累积入渗量和湿润锋的多因素计算模型,经验证该模型相关性较好。分析表明:土壤初始含水率对累积入渗量和湿润锋运移距离影响程度大于表施腐殖酸用量,均呈负相关。通过表施腐殖酸用量的减渗效应发现:累积入渗量的减渗率和湿润锋的减少率均与表施腐殖酸用量呈正相关。入渗结束后,土壤含水率随表施腐殖酸用量的增加而减小。(3)为了研究持续高温和昼夜交替状况下的裸地土壤水分蒸发特性,开展了表施腐殖酸条件下室内蒸发试验,探究了腐殖酸对土壤水分蒸发过程的影响。为加速蒸发采用红外灯作为热源,建立了红外灯光连续照射方式下和间断照射下的累积蒸发量模型,发现红外灯光连续照射方式下累积蒸发量呈递增的趋势,而红外灯间断方式下累积蒸发量呈波形递增的趋势。通过对累积蒸发量减少率的分析发现：土壤初始含水率相同时,累积蒸发量减少率随表施腐殖酸用量增加而增大;表施腐殖酸用量相同时,累积蒸发量减少率随土壤初始含水率的增加而减小。蒸发结束后,表施腐殖酸的方案的土壤含水率高于未表施腐殖酸的对照方案;间断照射下的土壤含水率大于连续照射下的土壤含水率。
[Abstract]:Humic acid is a kind of macromolecule organic matter, which can be used in agricultural production to improve soil. It also has the advantages of water saving, fertilizer saving, increasing production and environmental protection. In this paper, the effects of humic acid application on soil infiltration and evaporation are studied by laboratory experiments, combined with numerical calculation and theoretical analysis, which is of great significance for the development of agricultural water-saving and efficient utilization of water and fertilizer. The main conclusions of this paper are as follows: (1) in order to study the infiltration characteristics of humic acid solution, the orthogonal design method was used to arrange 16 orthogonal design schemes, and the one-dimensional vertical infiltration test of humic acid solution was carried out. Phillip model was used to fit the relationship between cumulative infiltration amount and infiltration time, and the correlation was good. The infiltration rate and wetting front migration rate of humic acid solution in steady infiltration stage are lower than that in clear water infiltration test. The multi-factor calculation models of cumulative infiltration and wetting front are established respectively, and the model is proved to have a good correlation. The effects of humic acid solution concentration, soil bulk density and initial soil moisture content on cumulative infiltration and wetting front migration distance were weakened in turn, and all of them were negatively correlated with the concentration of humic acid solution, soil bulk density and initial soil moisture content. The effects of different humic acid solutions on the impermeability were analyzed. It was found that both the reduction rate of cumulative infiltration and the decrease of wetting front were positively correlated with the concentration of humic acid solution. After infiltration, the distribution of soil moisture showed that the soil moisture content of humic acid solution infiltration scheme was lower than that of water infiltration test. (2) in order to study the infiltration characteristics of fresh water under the condition of surface humic acid application, the results showed that the soil moisture content of humic acid solution infiltration scheme was lower than that of water infiltration test. The uniform design method was used to arrange 12 groups of test schemes, and the one-dimensional vertical infiltration test of clean water was carried out under the condition of surface humic acid. It is found that the Phillip model is more effective in fitting the measured values of cumulative infiltration. In the stable infiltration stage, the infiltration rate and the wetting front migration rate of the humic acid application schemes were lower than those of the non-surface humic acid control scheme. The multi-factor calculation models of cumulative infiltration and wetting front are established respectively, and the model is proved to have a good correlation. The results showed that the effect of initial soil moisture content on cumulative infiltration and wetted front migration distance was higher than that of surface humic acid application, which showed a negative correlation between soil initial moisture content and accumulated infiltration and wetting front migration distance. Through the effect of surface application of humic acid, it was found that both the rate of cumulative infiltration and the decrease of wetting front were positively correlated with the amount of humic acid applied on the surface. At the end of infiltration, soil moisture content decreased with the increase of surface humic acid application. (3) in order to study the evaporation characteristics of bare soil water under continuous high temperature and day-night alternation, laboratory evaporation experiments were carried out under the condition of surface humic acid application. The effect of humic acid on the evaporation process of soil water was studied. In order to accelerate evaporation, infrared lamp is used as the heat source, and the model of cumulative evaporation under continuous irradiation mode and intermittent irradiation mode of infrared light is established. It is found that the cumulative evaporation amount of infrared light is increasing gradually under continuous irradiation mode of infrared light. On the other hand, the cumulative evaporation showed the trend of increasing waveform under the intermittent mode of infrared lamp. Through the analysis of the decrease rate of cumulative evaporation, it was found that the decrease rate of cumulative evaporation increased with the application of humic acid at the same time of initial soil water content. When the application of humic acid was the same, the cumulative evaporation rate decreased with the increase of initial soil moisture content. At the end of evaporation, the soil moisture content of the surface humic acid application scheme was higher than that of the non-surface humic acid application scheme, and the soil moisture content of intermittent irradiation was higher than that of continuous irradiation.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S152.7

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