The Effect Of Water Consumption And Water Use Efficiency Under Greenhouse Conditions

The problems of agricultural water resources shortage in our country,water and fertilization management extensive of greenhouse vegetables and serious waste of water resource were increasingly significant,especially under the condition of the facility cultivation environment,unreasonable factors such as environmental regulation can also cause the vegetables production and water use efficiency lower.Therefore,through the research on the rules of greenhouse vegetables transpiration and soil surface evaporation,analyses the key factors influencing the water,exploring the mechanism process of the surface evaporation to change the vegetable water consumption in order to reasonable water management and environmental regulation of greenhouse vegetable production to provide scientific theoretical basis.This test by weighing type lysimeter and miniature evaporator for technology,greenhouse tomato as the research object in the fall,to explore the water consumption of greenhouse tomato and soil evaporation law and dynamic relationship,reveal the mechanism of the soil evaporation changing crop water consumption process.Test set three treatment,treatment 1(FM)is a surface coated,treatment 2(FMS)for the surface is not coated,the treatment of 3(NFM)for the surface coated and simulation and processing of the same soil evaporation.The main results were as follows.1.In this experiment,the change trend of tomato transpiration rate was similar in all treatments.However,there was a significant difference in water consumption.Daily transpiration rate showed a bimodal curve.Greenhouse tomato transpiration rate with growth stage,was increased first and then decreased,the average evapotranspiration rate in the whole growth period was 2.28-3.26 mm·d-1.Treatment FM,FMS and NFM's total water consumption respectively is 265.35 mm,316.89 mm and 381.70 mm.Treatment FM Compared with FMS and NFM the total water consumption reduced 17.0%? 29.9%.Under the plastic film mulching,tomatoes' evapotranspiration rate can significantly reduce,and substantial reduction in evapotranspiration during the growth periods.2.The evaporation of tomato in autumn stubble greenhouse showed a decreasing trend with the prolongation of time.The temperature in the greenhouse significantly affected the soil evaporation(p<0.01).The higher the temperature,the greater the soil evaporation.The total soil evaporation during the whole growth period was 108.28 mm,accounting for 29.5%of the total water consumption of tomato.The soil evaporation at seedling stage,flowering stage and mature stage was 43.39 mm,45.66 mm and 19.22 mm,respectively,accounting for 71.3%,26.8%and 14.2%of the water consumption in each stage.It can be seen that the high temperature environment of the tomato(early stage)of the stubble greenhouse resulted in the highest soil evaporation and the largest proportion of the total water consumption.It also indicated that the soil evaporation during this period had a great influence on the change of tomato canopy microenvironment.3.Temperature is an important factor affecting the evapotranspiration rate of tomato.The temperature is positively correlated with the evapotranspiration rate,while the appropriate cooling at high temperature can increase the evapotranspiration rate and increase the evapotranspiration of tomato.The environmental factors(temperature,relative humidity,canopy internal temperature,canopy internal humidity,10 cm soil temperature)in the greenhouse significantly affected the evapotranspiration rate of tomato,and the effect of temperature was the largest.At higher temperatures(greater than 30 ?),the increased soil evaporation at the bottom of the FMS changed the changes in the microenvironment within the canopy(humidity increases,temperature decreases).The higher the temperature in the greenhouse,the higher the temperature of the canopy in the treatment of FMS compared to the treatment of FM.The higher the temperature reduction rate of FMS was,the higher the evapotranspiration rate was trend.It can be seen that the proper cooling of the greenhouse during high temperature can improve the evapotranspiration rate of tomato and enhance the evapotranspiration.4.Under the test conditions,the appropriate reduction of the temperature inside the greenhouse canopy can promote the growth,increase the yield and improve the water use efficiency.Comprehensive analysis of the appropriate temperature during the high temperature period can improve the tomato evapotranspiration rate and enhance the water consumption of tomato,and then achieve the positive effect of promoting tomato plant growth,increasing yield and improving water use efficiency.