ISWC OpenIR  > 水保所知识产出(1956---)
微润灌溉条件下土壤水盐运移规律研究
薛万来
Subtype硕士
Thesis Advisor牛文全
2014-05
Degree Grantor中国科学院研究生院
Place of Conferral北京
Keyword微润灌溉 土壤水分 盐分分布
Abstract

微润灌溉是一种连续灌溉技术,通过地埋管带方式,利用膜内外水势差作为
驱动力,将水缓慢输送到作物根区。由于其节水效果显著、能耗低等,近年来在
农业生产中开始得到运用。目前利用最为广泛的滴灌技术,由于其间歇灌溉的特
点,土壤蒸发和盐分淋洗作用同时存在,盐分分布呈现积盐-脱盐的反复过程,
并不能使作物根区保持完全脱盐的状态,对作物生长发育有一定消极影响。微润
灌溉则是一种连续的灌溉方式,由于其地埋的特点,蒸发作用微弱,利用微润灌
溉进行盐碱地利用,不但可以保证作物整个生育期的需水要求,而且可以使土壤
湿润层一直处在脱盐的状态。微润灌溉条件下土壤水盐运移规律的研究是正确利
用这一新型灌水方式的前提。为了探索不同影响因素下微润灌溉土壤水盐运移规
律,本文进行了微润灌溉室内模拟实验和温室种植试验。本文主要分析了入渗水
矿化度、压力水头、入渗水量对土壤水盐运移规律的影响及微润灌溉对温室番茄
生长及水分利用效率的影响。主要研究结论如下:
(1)矿化度对湿润体形状影响小,微润灌湿润体横剖面呈近似圆形;矿化度
对湿润体体积影响较大,矿化水湿润体体积大于清水的湿润体体积。当矿化度为
3g/L 时,微润灌湿润体湿润锋运移速率最大,湿润锋运移速率与时间呈幂函数
关系。矿化水可增加微润灌的累计入渗量,但累积入渗量与矿化度之间不是单调
关系,当矿化度为 3g/L 时,累积入渗量达到最大,土壤平均含水率也最大。当
矿化度低于 3g/L 时入渗水对土层盐分有一定的淋洗作用,矿化度进一步升高时,
入渗水对盐分的淋洗作用微弱;利用微咸水短期灌溉,土壤的平均含盐量与蒸馏
水处理之间没有显著差异
(2)土壤累计入渗量与压力水头呈正相关,土体微润带入渗量大于空气中,
同时建立了较高精度的预测不同压力水头下累计入渗量的模型;湿润锋运移距离
随压力水头增大而增加,各处理湿润体横剖面都近似为“圆形”,且湿润锋运移速率初期较快,后期逐渐变慢;土壤含水率最大值均出现在微润带附近,且压力水
头越大,土壤水分分布范围越广,土壤平均含水率越高。各处理土壤盐分分布呈
现出以微润带为轴心,向四周不断增大的趋势,同一深度土壤盐分含量与压力水
头呈明显的负相关关系,同时随压力水头的增加,盐分降低区深度的增幅在减小。
(3)湿润锋运移距离与入渗水量呈幂函数关系;随着入渗水量的增加,同一
深度处土壤含水量随之增加;入渗水量较小时,土壤剖面含水量曲线较为平缓,
入渗水量继续增大时,土壤剖面含水量曲线呈先陡直后平缓的变化特性;土壤含
盐量大小由微润带所在平面向外逐渐增大,且随入渗水量增加,土壤脱盐深度和
脱盐效率也逐渐增加,但脱盐深度比差异不大,湿润锋处的含盐量随入渗水量呈
指数增加趋势;微润带所在平面以下 5cm 各处理土层含盐量均低于初始含盐量,
入渗水量越大,土壤脱盐效果越明显,微润带所在平面以下 0-10cm 土层平均含
盐量在湿润深度为 15cm 时高于初始含盐量,土壤表现为积盐状态,当入渗水量
继续增大,微润带所在平面以下 0-10cm 土层土壤表现为脱盐状态。
(4)滴灌处理土壤水分的动态变化大于微润灌溉;从株高和茎粗的角度分析,
微润灌溉更有利于植物生长;两种处理番茄的光合速率日变化呈近似双峰曲线,
叶片的蒸腾速率和气孔导度日变化呈单峰曲线;无论是单位面积产量还是水分利
用,微润灌溉处理都优于滴灌处理;两种灌水方式下,番茄的耗水规律较为相似,
但滴灌处理番茄的耗水量大于微润灌溉处理。
关键词 :微润灌溉,土壤水分,盐分分布

Other Abstract

Moistube irrigation is a kind of continuous irrigation technique, through the
ground belt way, using the membrane water potential difference as a driving force,
driving water slowly to the crop root zone. Due to their remarkable water-saving
effect, low energy consumption, in recent years began to get used in agricultural
production. While the most widely used of drip irrigation technology, due to its
characteristics of intermittent irrigation, soil evaporation and salt leaching exist at the
same time, salt distribution - desalting process repeatedly, cannot keep the crop root
zone completely state of desalination, and has certain negative influence on crop
growth and development. In turn,Moistube irrigation is a kind of continuous
irrigation methods, because of its characteristics of ground belt way,Soil evaporation
is weak. When it used on saline-alkali land, not only can ensure the whole growth
period of crop water requirement, and can be kept moist soil layer in a state of
desalination. And thus the investigation of the rule of soil water and salt transport
under the condition of moistube irrigation is the precondition of correct use of this
new type of irrigation. In order to explore the rule of soil water and salt transport
under different influencing factors of moistube irrigation, this experiment has carried
on the laboratory simulation experiment and greenhouse cultivation experiment. This
experiment mainly analyzes the mineralization degrees, pressure head and infiltration
water amount on soil water and salt migration regularity and micro embellish the
influence of irrigation on the impact of greenhouse tomato growth and water use
efficiency. The main research conclusions are as follows:
(1)Degree of mineralization has small impact on the shapes of soil wetted zone, wetting front shape were similar to circle. Degree of mineralization has relatively
bigger influence on the volume of wetted soil.The volume of wetted soil in
mineralized water was bigger than that in pure water.The wetting front (horizontal,
vertical up and down) migration distance of 3g/L is farthest,the wetting front
migration distance has power function relationship with time. The mineralized water
can increase cumulative infiltration.However the relationship between cumulative
infiltration and degree of mineralization was not linear relationship.The cumulative
infiltration and average soil moisture content of 3g/L is biggest.The results of this
study provide reference for the utilization of moistube-irrigation with mineralized
water. When salinity is lower than 3 g/L, the infiltration of water has certain leaching
on soil salt content. When mineralization degree the increased further, the infiltration
of water for salt leaching with a smaller role. Using brackish water for short-term
irrigation, there were no significant differences between distilled water treatment and
brackish water treatment for average soil salt content.
(2) Cumulative infiltration was positively correlated with the hydraulic head;
infiltration of buried way is greater than the surface, while establishing a higher
accuracy mode to predict cumulative infiltration. Wetting front distance increases with
increasing hydraulic head, cross-section of wet body are similar to "round" and the
initial rapid rate of wetting front, the latter gradually slow down. Soil moisture
maximum values were close to the moistube and the greater the hydraulic head, the
wider the range of soil moisture distribution, the average soil moisture content is
higher. The distribution of soil salt under different hydraulic head presents for
moistube with axis, the characteristics of the trend of increasing. The same depth of
soil salt content and pressure head are obvious negative correlation. With the increase
of the hydraulic head, the cut in reducing zone depth of growth of salt.
(3) The wetting front transport distance and infiltration water is power function
relationship; With the increase of infiltration water amount, the same depth of soil
moisture content increased; The amount of infiltration water is small, the water
content of soil profile curve is relatively flat, Along with the infiltration of water
continues to increase, the water content of soil profile curve after first steep and gentle
change characteristic; Soil salinity in moistube as the center outward gradually   increased. And with the increase of water infiltration, soil desalting depth and
desalting efficiency also increase gradually, but the desalting depth is not significant.
The salt of wetting front with the infiltration water increased exponentially. Each soil
salt content below 5cm of the plane of the moistube is lower than the initial salt
content. Infiltration of water quantity, the more soil desalting effect is obvious. The
average soil salt content of 0 to 10 cm is higher than the initial salt content under the
moist depth of 15 cm, when the infiltration water continues to increase, 0 to 10 cm
soil layer soil performance for desalination.
(4) Drip irrigation soil moisture dynamics frequently than moistube irrigation,
moistube irrigation can adjust itself according to water demand of plants. From the
perspective of plant height and stem diameter, moistube irrigation is more conducive
to plant growth. Meanwhile two treatments tomato photosynthetic rate variation was
similar to bimodal curve, leaf transpiration rate and stomata conductance showed a
single peak curve;Both yields per unit area or water use efficiency, moistube
irrigation is better than drip irrigation; Water consumption laws are similar between
two irrigation methods, but the water demand of drip irrigation is bigger than
moistube irrigation.
Key word: Moistube irrigation, Soil moisture, Distribution of salt

Language中文
Document Type学位论文
Identifierhttp://ir.iswc.ac.cn/handle/361005/9006
Collection水保所知识产出(1956---)
Recommended Citation
GB/T 7714
薛万来. 微润灌溉条件下土壤水盐运移规律研究[D]. 北京. 中国科学院研究生院,2014.
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