Study On Integrated Application Technology Of Fertilizer,Watering And Carbon Dioxide On Cucumber In Solar Greenhouse

Because of the relative closed condition in solar greenhouse, it leads to the lack of CO₂, and theninduces many problems such as poor growth, inhibition of photosynthetic efficiency and decrease inyield. After putting forward the integrated application technology of fertilizer, watering and carbondioxide (IATFWC), it will be contributed to improve the facility culture environment and photosyntheticefficiency so as to promote the growth of plants. This study researched about the variation of CO₂concentration in the greenhouse and compared three methods of carbon dioxide application. Based onthe application technology of carbon dioxide and the coupling technology of fertilizer and water, wedeveloped IATFWC. Through reseaching about the growth, physiology, production and quality oncucumber, it provided the theoretical basis for the implementation of IATFWC. The main achievementsof our studies are as following:1. Comparing with cloudy day, the photosynthesis of plants is stronger in clear days, and the biggerplants consume more CO₂than smaller ones. Application of CO₂is needed in clear flowering andfruit setting stage. Fruit vegetables need a large number of CO₂in fruit expanding process forphotosynthesis, but application of CO₂is not needed in seedling stage and cloudy days.2. Increasing the concentration of CO₂has remarkable effect to promoting the cucumber growth,increasing yield and improving nutrition qualitative. Comparing with the other treatments,supplying with CO₂can increase the yield by7829kg·667m-2. The influence of application withCO₂to the yield is mainly in the middle and late stage, but has little impact on the early stage. Theapplication of CO₂has remarkable effect on the soluble solid state material and Vc of cucumber.Organic soil cultivation can play a part in supplying CO₂in solar greenhouse. The influence ofOrganic soil cultivation to the yield is mainly in the early and middle stage, but has little impact onthe late stage.3. In the situation of optimizal irrigation, we reseached about effect of nitrogen and potassiumfertilizer to yield and quality of cucumber. The results show that, at the same amount of nitrogen,more content of potassium(N:K=1:1.4¹.8)could improve the plant growth and increase thecontent of chlorophyll in the leaf and improve the net photosynthesis rate. The ratio of N K1:1.8isthe best treatment.4. The method of application of carbon dioxide with straw reactor (SR), sulfate-ammoniumbicarbonate (SAB) and ammonium bicarbonate gasification filtering (ABGF) can well improve theCO₂concentration in solar greenhouse, but the last two can better control the CO₂concentration.SAB costs less than ABGF, but its strong reaction and corrosion make its inconvenient operation.ABGF is moderate and can produce more pure CO₂, so we can use this method to applicate CO₂and realize IATFWC. The concrete application proportion is that, to improve500ppm·667m²insolar green house, it needs7.2kg of ammonium bicarbonate in reaction chamber,5.32L of wateradded4.68L of phosphoric acid in level1filter,10L of water in level2filter, and then ohmic heat ammonium bicarbonate to increase carbon dioxide. After the reaction, it needs to mix the solutionof level1and2fliters and added with28.8kg fertilizer (K₂O52%), and then irrigated throughautomatic dropper.5. IATFWC can significant improve the root activity of cucumber, increase the net photosyntheticrate and yield. Through the analysis of the quality of cucumber, it can remarkable improve thecontent of the soluble solids, soluble sugar and Vc than the early stage, and reduce the nitratecontent.