Water Movement In Different Texture Soil And Growth Of Greenhouse Vegetable Under Moistube Irrigation

Moistube irrigation is a new water-saving irrigation technology.Compared with traditional irrigation,it can effectively reduce soil evaporation,improve soil environment,improve water use efficiency.Compared with drip irrigation,sprinkler irrigation and micro-irrigation,moistube can adjustable water head to control water supply pressure,meeting the crop soil water of the different growth stage.It has the advantages with more water-saving,energy-saving,yield-increasing.To verify that the moistube irrigation on water saving effect and economic benefit is superior to ordinary irrigation,this paper carried out the tests of 3 kinds of vegetable planting.To explore the situation of moistube tube flow,wetting front migration and water distribution of the soil of different texture,in different water pressure,this paper carried the indoor simulated test.Thus,it can be used as reference for the application and promotion of micro-irrigation.The main conclusions of this study are as follows:In the indoor simulation experiment,water pressure had obvious effect on the cumulative infiltration and infiltration rate.There was a linear relationshipbetween the cumulative infiltration rate and the test time.The migration distance of wetting front in all directions continued to expand with the test time,but the migration rate decreased gradually.The migration distance of the wetting front in two the horizontal direction were close.The wetting front distance had the relationship of power function with test time with high fitting degree.Moisture content of wetting body exhibited a step change.And the soil moisture content gradually became smaller as the center to the micro-tube.In the tests of clay loam soil and the mixed soil,the wetting front movement distance in the vertical downward direction was greater than the migration distance of the other three directions.From the analysis of wetting cross-section,the wetting front approximated regular circle.And wetting was approximate to the cylinder.In the experiment of sand,the migration distance in two horizontal direction were greater than the migration distance in the vertical direction.At the same time,the vertical downward were greater.The wetting front was approximate to the ellipse with long axis being far greater than the short axis.And wetting body approximated elliptical cylinder.In the tests of clay loam soil and the mixed soil,from the micro-tube running the same distance,pressure head had an great impact on soil moisture content.But in the test of sand,water pressure had little effect on soil moisture content.In the test of vegetable planting,vegetables daily water consumption had the change with generally increasing and then decreasing.The trend of soilmoisture of various planting box of moistube irrigation treatments was increasing first and then to a stable state.The curve of vegetable plant height was "S" type.The situation of the pressure head of 2.0m and depth of 4cm was most conducive to the growth of the four seasons spring onion,with maximum yield and water use efficiency.The situation of the pressure head of 2.0m and depth of5 cm was most conducive to the growth of the purple lettuce,with maximum yield and water use efficiency.The situation of the pressure head of 2.0m and depth of 8cm was most conducive to the growth of the cabbage,with maximum yield and water use efficiency.Except the treatment with pressure head of 2.0m and depth of 8cm in the test of the purple lettuce,the amount of water used for vegetable under the condition of moistube irrigation was less than the condition of ordinary irrigation.Also,the yield of vegetable of moistube irrigation was higher than the ordinary irrigation.