残膜量对土壤水分运移和温室番茄生长的影响

发布时间：2018-02-23 17:05

本文关键词： 残膜残膜量阻滞不确定性土壤水分运移番茄生长　出处：《中国科学院大学(中国科学院教育部水土保持与生态环境研究中心)》2017年硕士论文　论文类型：学位论文

【摘要】：地膜具有增温保墒、保水抑盐,改善土壤水肥气热条件,促进作物高产稳产等作用,在北方地区大面积推广应用,且使用量和覆盖面积呈增长趋势。但地膜厚度一般为0.008 mm,拉伸负荷较低,易破碎,残膜机械回收率低。随着使用年限的增加,田间残膜量逐年增加,对土壤—作物生态系统的负面效应也日益凸显。本研究通过室内土箱、土柱模拟和温室番茄种植相结合的试验方法,设置了6个残膜量水平,分别为0、80、160、320、640和1280 kg/hm2,研究了不同残膜量对土壤水分垂直入渗、蒸发和水平扩散及番茄生长发育的影响,为残膜污染地区农艺管理方式提供参考。本文的主要结论如下:1)残膜延长了土壤水分入渗时间,入渗至45 cm土层耗时随残膜量增加而增大;入渗一定时间,含残膜处理的入渗曲线与无残膜曲线分离,分离时间随残膜量增加而提前,分离时间与残膜量之间呈对数函数减小;Kostiakov模型更适合模拟含残膜土壤的入渗过程;湿润锋运移距离与入渗时间呈幂函数增长关系,但湿润锋运移距离随残膜量增加而递减;随残膜量增加,作物适宜生长区和水分分布重心逐渐上移。残膜对土壤水分入渗有较大的不利影响,其影响程度随残膜量增加而增大。2)随着残膜量增加,湿润锋垂直运移速率和累积入渗量逐渐减小;残膜量80 kg/hm2时,湿润锋运移速率大幅下降;累积蒸发量随残膜量增加而递减,而蒸发系数呈递增趋势;随残膜量增加,0~10 cm和20~45 cm土层质量含水率呈降低趋势,而土壤水分的变异系数呈增加趋势,残膜加剧了土壤水分垂直分布的变异性,残膜量320 kg/hm2的处理会出现表土层“板结”现象。基于Gibbs抽样算法分析表明,Kostiakov入渗模型和Rose蒸发模型各参数的95%后验置信区间上下限的差值和标准差均随残膜量增加而增大,累积入渗量和累积蒸发量的95%后验置信区间面积呈增大趋势,土壤累积入渗量和累积蒸发量的不确定性随残膜增多而增强。3)残膜是一种难降解持续性污染物,会降低水平湿润锋运移速率、累积入渗量和土壤水分扩散率,残膜对土壤水分水平运动的阻滞作用随残膜增多而增强。水平湿润锋运移速率、土壤含水率和累积入渗量均随残膜量增加而减小,残膜量≥160 kg/hm2时,水平湿润锋运移速率和累积入渗量大幅降低;残膜对土壤水分水平运动的阻滞系数与残膜量呈正相关关系,残膜阻滞系数的最大增长率出现在80~160kg/hm2残膜量区间,增长率达251.15%;随残膜量的增加,阻滞作用较强区域距离入渗点的距离增大,Boltzmann系数和水分扩散率则逐渐减小,土壤基质势对水分水平运动的驱动作用和土壤持水能力逐渐减弱;但混有残膜的土壤水分水平运动过程,仍符合土壤水分扩散率单一参数模型和Kostiakov入渗模型。4)残膜阻碍了番茄苗期和开花坐果期根系的生长,根体积、根长密度和根干质量密度均随残膜量增加而降低;随着残膜量增加,苗期和开花坐果期的株高和茎粗均呈减小趋势,且株高和茎粗的增长速率逐渐降低。番茄养分积累的始盛期和高峰期随残膜量增加而提前,番茄追肥的最佳时期也应提前。在番茄苗期和开花坐果期,根系、茎秆、花和幼果的干物质量均随残膜量增加而减少,而叶片的干物质量呈递增趋势。残膜对番茄苗期根系、地上部生长和干物质积累的阻碍作用高于开花坐果期。由此可见,残膜对番茄苗期的危害强于开花坐果期,且干物质积累的始盛期和高峰期均随残膜量增加而提前,加强番茄苗期水肥管理和提前水肥施加时间是减轻残膜危害的有利措施。
[Abstract]:Plastic film with temperature raising, water salinity, improve soil water and fertilizer gas and heat conditions, promote crop yield effect, popularization and application in large area in the northern region, and the usage and coverage area increased. But the film thickness is 0.008 mm, the tensile load is low, easily broken, mechanical recovery of residual film the rate is low. With the increase of service life, the film is increasing year by year, the negative effect on soil plant ecological system has become increasingly prominent. In this study, through indoor soil box test method, soil column simulation and greenhouse tomato planting combination, set up a level 6 film residues, respectively 0,80160320640 and 1280 kg/hm2 the study, different film residues on soil water vertical infiltration, evaporation and diffusion and growth and development of tomato, and provide a reference for the management of regional agronomic film pollution. The main conclusions of this paper are as follows: 1) film extended soil Water infiltration time and infiltration to the soil layer of 45 cm with the time of residue film was increased; infiltration time, residual membrane treatment infiltration curve separation and no residual membrane separation time curve, and with the advance of residue film was increased, the separation between time and film residues logarithmic reduction; Kostiakov model more suitable for the infiltration process simulation of residual film soil; wetting front transport distance and infiltration time exponentially increase, but the wetting front distance with plastic film increased with the increase of volume decline; residual film, crop growth region and water distribution center gradually move up. The residual film on soil moisture infiltration greater adverse effects, the influence degree with the increase of residual film increases with increasing the amount of residual film.2), vertical wetting front migration rate and the cumulative infiltration decreased gradually; residue film was 80 kg/hm2, the wetting front migration rate decreased significantly; cumulative evaporation amount with film residues Decreased while the evaporation coefficient increased with the increase of the amount of residual film; 0~10, cm and 20~45 cm soil quality moisture content decreased, while the coefficient of variation of soil moisture increased, the residual film exacerbated the variability in the vertical distribution of soil moisture, processing of residue film was 320 kg/hm2 will appear in surface soil "hardening phenomenon. Analysis shows that the Gibbs sampling algorithm based on Kostiakov infiltration model and Rose evaporation model parameters of the 95% posterior confidence limit differential difference and standard interval were decreased with the increasing amount of residual film, cumulative infiltration and cumulative evaporation of the 95% confidence interval of the posterior area increased, the soil accumulation infiltration and cumulative evaporation uncertainty with plastic film increased and enhanced.3) film is a kind of difficult degradation of persistent pollutants, will reduce the level of transport velocity of wetting front, cumulative infiltration and soil moisture diffusion rate, residual coating on Soil Block water horizontal movement with the increasing level of residual film is enhanced. The wetting front migration rate, soil water content and cumulative infiltration decreased with the amount of residual film decreases with the increase of residue film was more than 160 kg/hm2, the level of transport velocity of wetting front and cumulative infiltration were greatly reduced; retardation coefficient of plastic film on the soil the level of soil water movement and the amount of residual film correlation, maximum growth rate of the residual film block coefficient in the range of 80~160kg/hm2 film residues, a growth rate of 251.15%; with the increase of the amount of residual film, blocking effect of strong regional infiltration distance the distance increases, the Boltzmann coefficient and the moisture diffusion rate is gradually reduced, the soil matrix the water potential on the horizontal movement of the drive function and water holding capability of soil decreased gradually; but mixed with the level of soil water movement process of plastic film, soil moisture diffusion rate is still in line with the single parameter model and Kostiakov infiltration model.4) film Hinder the root of tomato seedling and flowering stage of growth, root volume, root length density and dry mass density with film residues increased; with residual film increased, seedling stage and flowering stage of the plant height and stem diameter decreased, and the plant height and stem diameter growth rate gradually tomato nutrient accumulation was decreased. The peak and peak with the increase of residual film in advance, the best period of tomato fertilizer should also advance. In tomato seedling stage and flowering stage, root, stem, flower and young fruit dry weight increased with the amount of residual film decreases, while the leaf dry weight increased trend. Root residual coating on tomato seedling, higher flowering and fruit setting stage, growth and dry matter accumulation of aboveground obstacles. Thus, residual coating on tomato seedling to harm the flowering and fruit development stage, and the dry matter accumulation of the beginning period and the peak increased with the increase of early film residues It is a favorable measure to strengthen the management of water and fertilizer in tomato seedling stage and the time of applying water and fertilizer ahead of time to reduce the damage of the residual membrane.

【学位授予单位】：中国科学院大学(中国科学院教育部水土保持与生态环境研究中心)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S152.7;S626;S641.2

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