Research Of Cucumber Water Requirement With Drip Irrigation Under Plastic Mulch In Greenhouse

Drip irrigation under mulch is an advanced technique combined the trickle irrigation technique with the polyethylene film planting technique. It has the advantages of saving water and enhancing yields. Now there is little about irrigation scheduling of drip irrigation under plastic mulch in solar greenhouse. So in practice the conventional irrigation mode is often be used. Drip irrigation under mulch reduces soil evaporation among plants, improves evapotranspiration, changes the water requirement of crop. So the schedule of drip irrigation under plastic mulch could not be substituted by the conventional irrigation model. As stated above, this paper studied the cucumber water requirement of drip irrigation under mulch in solar greenhouse and the main results are as follows:(1) Compared treatments A1-A4 with treatments Bl—B4, first ones have larger leaf area, bigger stem diameter, stronger root activity and quicker growth of cucumber fruit. It is ideal mode that the treatment is irrigated every 7 days with water amount of 15mm for each time during the bloom stage.(2) The quantity of Vc and soluble sugar content in cucumber fruit is increasing with the increase of water consumption in some degree and then decreasing with it. So there is a parabola relationship in them. The quantity of Vc is the highest in cucumber fruit that is irrigated every 7 days with water amount of 15 mm and water consumption of 185.9mm in bloom stage. And the quantity of the soluble sugar is the highest when water consumption of cucumber is 171.8mm.(3) Through analysis of cucumber leaf photosynthesis, it shows that diurnal change of photosynthesis rate of both treatments A1-A4 and treatments B1-B4 is a curve with two peaks, and the difference is that photosynthesis rate of treatments A1-A4 is higher than that of treatments B1-B4. Water in bloom stage has a little effect on cucumber transpiration, and has a larger effect on stomatal conductance of treatments A1-A4 than on that of treatments B1-B4. And in fruit stage, photosynthesis rate, transpiration rate, stomatal conductance are increasing with the increase of water amount. And the change trend in fruit stage is similar to that in bloom stage.(4)Analyzing dynamic change of soil water in bloom stage and fruit stage, it shows that treatments A1-A4 is better, equal to soil water content in 80%-85%. The yield of...