Study On Tomato Water Demand And Irrigation Decision In Solar Greenhouse

This paper mainly studied the law of tomato water demand and irrigation index under drip irrigation under solar greenhouse film.In different irrigation water of tomato as test object,monitoring the growth of tomato,physiology,quality,yield and other indicators,analyzes the soil moisture,stem flow,the change of the irrigation decision indicators such as photosynthetic,and according to the law of water requirement in these indicators analysis of tomatoes and water indicators,and according to the index of water demand and irrigation relationship,and obtained the following results:(1)The changes of soil moisture content under different degrees of deficient irrigation were analyzed.The moisture content of soil layer below 20 cm was proportional to the irrigation amount.The soil variation coefficient was > in the shallow layer and > in the middle layer.(2)Studies have found that indicators related to tomato water shortage include: stem flow rate,net photosynthetic rate,transpiration rate,intercellular CO2 concentration,chlorophyll fluorescence parameter SPAD and CWSI,where stem flow rate,net photosynthetic rate,and transpiration rate,intercellular CO2 concentration,chlorophyll fluorescence parameter SPAD are positively correlated with irrigation water amount,while CWSI is negatively correlated with irrigation water amount.(3)The dry matter of tomatoes at different growth stages under different irrigation water treatments is proportional to irrigation water amount,and irrigation water amount affects yield and quality.Through the analysis of principal component analysis,it is concluded that T4 55%ET0 treatment is the optimal irrigation system among the four treatments,indicating that irrigation water amount at 55%ET0 improves quality of tomatoes,but reduces yield at the same time.(4)Using correlation and path analysis,analysis of meteorological data and stem flow rate respectively the relationship between the net photosynthetic rate,transpiration rate,using meteorological data calculate respectively a plant stem flow rate,net photosynthetic rate,transpiration rate,using the fuzzy set theory,according to the soil moisture content of stem flow rate,net photosynthetic rate,transpiration rate for irrigation decision on May 14 and May 24,for example,verify the four irrigation decision index can take advantage of the fuzzy set theory for irrigation decision...