| Soil secondary salinization caused a serious recession, such as a serious of agricultural production recession, agricultural productivity reduce or no production, has become a serious problem restricting the development of agriculture at present. Moistube–irrigation as a new type of water saving irrigation methods, not only has the drip irrigation water saving advantages, such as save water, save work, decrease soil surface evaporation, increase crop water use efficiency, etc. But also it has maked up for some defects existing in the drip irrigation at the same time, such as high energy consumption, easy jam, can not continuous water supply, etc. It has meet the current world within the scope of water saving irrigation in the direction of low energy consumption and accurate irrigation technology development trend. Because of its characteristics of continuous irrigation,it has becomed a kind of control and improve the irrigation soil secondary salinization at the same time. Research on moistube–irrigation were largely concentrated in the indoor simulation study stage at present, the field experimental study is relatively little. The research studied the effective utilization of mild saline soil and problems of soil secondary salinization caused by unreasonable irrigation in greenhouse. The research choosed tomato coverd of membrane in greenhouse as the research object. We have analyzed the effect of the different buried depth on the growth of tomato under greenhouse film, soil water and salt migration regularity and the effect of salinity on tomato. The research has put forward the best buried depth and the key salt in different growth stages. It provided reference for application and popularization of moistube–irrigation. This research mainly draw the following conclusion:(1) Different buried depth and pressure head on tomato growth and water use efficiency has a larger impact.A shallow depth increases will lead to ineffective evaporation surface, water use efficiency;To dive deeper causes moisture deep seepage influence of wetting body shape and position, affect the distribution and the water absorption of crop root system.Buried deeply 15 cm is 140 cm, pressure head to improve the processing of tomato water use efficiency, with good water saving effect.(2) The maximum average moisture content during whole growth period was tomato in the embedded depth of 15 cm, 20 cm depth.In this experiment, the micro embellish filling and buried deeply when the 15 cm more for tomato root water absorption, improved the tomato water use efficiency.(3) With the increase of soil depth, soil moisture content between membrane, membrane within gap is reduced.The highest soil moisture content and salinity are lowest in 10 ~ 20 cm soil layer, the phase depth soil moisture content, salt content highest minimum 15 cm.Membrane within 0 ~ 40 cm soil layers in a state of relative desalting, the nearer the micro embellish belt, desalting effect more apparent, 40 ~ 60 cm soil layer for the relative state of salt.(4) The whole growth period of tomato, the root zone soil cation easy elution order is: Na+> K+ >Mg2+>Ca2+,anionic easy elution order is: Cl-> HCO3->SO42-.Root zone salt over time and reduce the main is to reduce the content of Na+ and Cl-, followed by K+and Mg2+, other ions is a growing trend over time.Buried deeply the processing of 15 cm(Na++K+)/( Ca2++Mg2+)in the minimum ratio of soil best.(5) In the end of seedling, flowering results and salt content of dry matter weight and plant height, leaf area index significantly harm the key salt were 0.134%, 0.116% and 0.125%, respectively, the key to affect the production of salt is 0.108%.In each growth stage, the soil salt content and plant height, dry matter weight, leaf area index and yield were extremely significant negative correlation. |
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