| In order to find out the water migration characteristics of the insterted subsurface drip irrigation and the application mode in greenhouse vegetables planting,this study designed the test from the following four aspects:(1)flow rate test,two factors were set up in the experiment,the different inserted depth(0cm(air),5 cm,10 cm,20 cm),pressure(0.05 MPa,0.08 MPa,0.1 MPa,0.15 MPa,0.25 MPa).The relationship between flow rate and pressure of irrigator under different inserted depth was studied;(2)water transport test.A test factor was set up to study the water transport law of inserting underground drip irrigation under different insertion depths(0 cm,10 cm,20 cm).(3)pot experiment.One experimental factor was set in the experiment.The effects of different buried depths(5cm,10cm,15cm)of the irrigators on the yield,growth characteristics and quality of potted pepper were studied.(4)greenhouse planting experiment.Two experimental factors were set in the experiment.Three irrigation methods were set up:the insterted drip irrigation emitter was inserted into the crop root(SDI-R)?the insterted drip irrigation emitter was inserted between two crops(SDI-M)and the surface drip irrigation(DI).The lower irrigation limits set four levels:60%of?_F at flowering/fruit-setting stage,60%of?_F at the mature harvest stage(F60M60),60%of?_F at the flowering/fruit-setting stage,70%of?_F at the mature harvest stage(F60M70),70%of?_F at the flowering/fruit-setting stage,60%of?_F at the mature harvest stage(F70M60),70%of?_F in the flowering/fruit-setting stage,70%of?_F at the mature harvest stage(F70M70).The effects of different irrigation limits on the growth,water consumption characteristics and yield of greenhouse vegetables were studied.The above four experiments were carried out in order to clarify the characteristics of water transport in different buried depths,the suitable buried depth of the irrigator in potted pepper,and the different effects of different irrigation modes and irrigation water limits on greenhouse green eggplants to obtain the application model of irrigator in potted and greenhouse vegetables planting,so as to provide reference for the scientific and rational application of insterted subsurface drip irrigation in vegetable facilities.The test results show that:(1)Compared with the flow rate in the air,the flow rate of the irrigator buried in the soil decreases by 25%~41.4%.Under the same pressure,under the condition of 0.05~0.08 MPa,the greater the depth,the smaller the cumulative discharge and flow rate;under the condition of 0.1~0.25 MPa,the maximum discharge and discharge are at the depth of 10 cm,followed by the depth of 20 cm.Under the same inserted depth,the relationship between flow rate and pressure is power function,and the correlation coefficient R~2 is more than 0.85.(2)The distance of wetting front migration is power function with time,and the correlation coefficient R~2 is greater than 0.9.The transport rate of 0 cm depth is the highest,followed by 10 cm depth.At the same inserted depth,the transverse migration rate is greater than the longitudinal one,and the difference between the two is the smallest when the inserted depth is 0 cm,and the difference between the inserted depth of 10 cm and 20 cm is large.The larger the inserted depth,the smaller the wetting body,and the farther the wetting body is from the surface of the soil.(3)Compared with flooding irrigation,insterted subsurface drip irrigation can promote crop growth better.When the depth of insertion is 10 cm,plant growth is the best,yield and fruit weight are also the highest.By comprehensive analysis of physiological indicators,yield,fruit weight and other indicators,it is concluded that the optimal depth of insertion drip irrigation in potted pepper is 10 cm.(4)Under the condition of insterted subsurface drip irrigation,when the irrigation water limit is F60M70,the yield and WUE of tomato are the highest,56046.30 kg/hm~2 and 20.43 kg/m~3 respectively,and the single fruit weight,transverse diameter and vertical diameter are the largest.Therefore,considering the economic benefits and water-saving benefits,it is concluded that under SDI-R condition,the irrigation water limit at flowering and fruit setting stage should be 60%of field capacity and 70%of field capacity at ripening and picking stage.Under the two insertion conditions,when the irrigation water limit is F60M70,and the yield and water use efficiency are the highest,which are greater than surface drip irrigation.Compared with surface drip irrigation,water consumption decreased by 35.29%and water use efficiency increased by 44.17%.But compared with emitter inserted into the crop root,the quality will be decreased.The results show that the suitable inserted depth in the pot was 10cm,the insterted subsurface drip irrigation can increase yield and save water compared with surface drip irrigation,and the irrigation water limit of insterted subsurface drip irrigation should be 60%and 70%of field capacity at flowering and fruit setting stage and mature harvesting stage respectively.In this experiment,the irrigator inserted in the middle of the crop will lead to a decrease in quality. |
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