干旱区压砂地微咸水补灌对土壤水盐运移规律及西瓜生长影响的研究

发布时间：2018-01-04 11:14

本文关键词：干旱区压砂地微咸水补灌对土壤水盐运移规律及西瓜生长影响的研究　出处：《宁夏大学》2017年硕士论文　论文类型：学位论文

【摘要】：本文主要以大田试验为基础,结合土柱模拟试验,分析了宁夏中部干旱区微咸水补灌对压砂地土壤水盐分布及西瓜生长、产量、品质和耗水规律的影响;分析了在没有种植西瓜的条件下,不同微咸水灌水量的土壤水盐运移规律,并对比分析了在相同灌溉量条件下裸地与覆砂处理的土壤水盐运移特征。结果表明:(1)微咸水补灌提高了压砂地西瓜根系分布区的土壤含水量,同时西瓜耗水量与微咸水灌水量呈线性增加趋势。(2)从西瓜全生育期土壤盐分变化来看,不灌水处理基本呈平衡状态;灌水定额为15 m3/667m2处理,0-100cm 土壤盐分含量增加了 16.90%,呈累积状态;而灌水定额为30和45m3/667m2处理,0-100cm 土层土壤盐分含量分别减少了 9.24%和14.72%,呈淋洗状态。从全生育期土壤盐分离子变化分析,HC03-主要集中在土壤浅层或主根区,并在西瓜全生育期内各处理平均减少4.47-24.75%。Cl-、SO42-、Na+含量分布均随土层深度的增加呈增加趋势,在灌水15m3/667m2处理下,HCO3-、Cl-、SO42-、Mg2+、Na+尤其在0-40cm 土层含量明显增加,在灌水定额30和45m3/667m2处理下,上述离子在0-40cm 土层含量减少。Ca2+含量在土层之间波动较小,经各灌水处理呈减小趋势。(3)各灌水处理与不灌水相比,促进了西瓜的生长并提高了西瓜产量,其中15 m3/667m2处理效果最明显,灌水处理增产幅度在20.2-50.9%之间,但降低了叶绿素含量;西瓜水分利用效率随着微咸水灌水量的增加呈线性减小趋势,当补灌量为15 m3/667m2时,水分利用效率达到12.3 kg/m3;西瓜的纵横径、Vc含量随着灌水量的增加呈增加的趋势,但灌水处理也降低了瓜心和瓜周(阴阳面)可溶性固形物含量及瓜液pH值。西瓜总酸度、可溶性糖含量差异性不显著。(4)从土柱模拟试验中可以发现,随着灌水时间的延后,各处理土壤水分稳定点上层的土壤水分含量逐渐下渗减小,下层的持续累积增大,并且灌水量越大,表层(尤其5cm 土层)水分变化越稳定;微咸水灌溉覆砂处理土壤盐分峰值不断向下推移,表层(尤其5cm土层)盐分呈减少趋势。随微咸水灌水量增加,湿润锋、土壤盐分峰值不断向下运移。通过独立样本T-检验分析表明,覆砂处理相比裸地处理具有显著的保水、抑盐作用。
[Abstract]:This paper is mainly based on the field experiment, combined with the simulated experiment of soil column, analyzed the drought zone of middle Ningxia brackish water irrigation on the yield pressure distribution of soil water and salt and sand watermelon growth, and affect the quality and law of water consumption; analyzed in the absence of watermelon planting conditions, different saline water irrigation the soil water and salt migration law and comparative analysis under the same irrigation amount under the condition of bare land and sand with soil water and salt transport features. The results showed that: (1) the brackish water irrigation increased pressure sands watermelon root distribution area of soil moisture and water consumption, watermelon and saline water irrigation (increased linearly. 2) from the change of soil salinity in the whole growth period of watermelon, no irrigation in equilibrium; irrigation quota of 15 m3/667m2 treatment, soil salt content of 0-100cm increased by 16.90%, a cumulative state; and the irrigation quota was 30 and 45m3/667m2 Daniel, soil salinity, soil 0-100cm decreased by 9.24% and 14.72%, a state. From the analysis of changes in leaching of soil salt ions in the whole growth period, HC03- mainly concentrated in the shallow layer of soil or root zone, and the watermelon in the whole growth period each treatment to reduce the average 4.47-24.75%.Cl-, SO42-, Na+ content decreased with soil depth increases. The increasing trend in irrigation, 15m3/667m2, HCO3-, Cl-, SO42-, Mg2+, Na+, especially increased in 0-40cm soil layer in 30 and 45m3/667m2 in the treatment of irrigation quota, the decrease of.Ca2+ content in soil ion between the fluctuation in the layer of 0-40cm content, after all the irrigation treatments showed decreasing trend. (3) and compared to the irrigation irrigation treatment, promote the growth and improve the yield of watermelon watermelon, of which 15 m3/667m2 treatment had the most obvious effect, irrigation treatment increased in the range of 20.2-50.9%, but reduced the chlorophyll content in the West; Melon water use efficiency decreases linearly with increasing trend of brackish water irrigation, when the irrigation amount was 15 m3/667m2, the water use efficiency reached 12.3 kg/m3; watermelon freely diameter, Vc content increase with the increase of irrigation amount, but irrigation treatment also decreased the heart and melon melon week (yin and yang side) the content of soluble solids and liquid pH value. The total acidity of melon watermelon, the soluble sugar content had not significant difference. (4) in the test can be found from the soil column simulation, with the delay time of irrigation, the soil moisture content of soil water stable layer gradually decreased the infiltration, sustained accumulation of lower increases. And the greater the amount of irrigation, the surface (especially 5cm soil moisture change) more stable; brackish water irrigation in sand soil salt peak downward over the surface (especially 5cm soil) salinity showed a decreasing trend. With the increase of brackish water irrigation, soil wetting front. The results of the independent sample T- test show that the sand cover treatment has a significant water retention and salt suppression effect compared to the bare ground treatment.

【学位授予单位】：宁夏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S651;S273.5

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