Study On Nutrient Solution Irrigation Mode Of Eggplant Closed Circulation Tank Culture

Open systems are often used in substrate cultivated production,and there are problems such as nutrient solution emission,soil and water pollution,and salt accumulation in roots.The closed circular tank culture system can reduce the outflow of nutrient solution and recycle nutrient solution after recycle,filtration and disinfection,but it lacks standardized irrigation mode of nutrient solution.Under current background,this thesis takes the eggplant with high consumption in North China as the research object,sets the irrigation amount and frequency of different nutrient solutions,and finally clarifies the irrigation mode of eggplant closed circular tank culture nutrient solution,in order to form a low cost,water saving,fertilizer saving and ecological efficient soilless cultivation vegetable production system.The main conclusions are as follows:（1）The plant height,stem diameter,biomass accumulation,seedling index,yield and water use efficiency of eggplant showed a trend of first increase and then decrease with the increase of nutrient solution irrigation amount,and the highest value was at1500 m L.EC value,leaf number,Fo,soluble sugar content and soluble solid content in root zone decreased with the increase of irrigation amount.Root activity,p H value of root zone solution,substrate water content,net photosynthetic rate,stomatal conductance,transpiration rate,intercellular CO₂ concentration,Fm,Fv/Fm and Fv/Fo increased with the increase of irrigation amount.The results of principal component analysis showed that 1500 m L irrigation nutrient solution per eggplant had the highest score.（2）The root volume,plant height,net photosynthetic rate,stomatal conductance,transpiration rate,biomass accumulation,single fruit weight and yield of eggplant gradually increased with the increase of irrigation frequency,and the EC value of root solution and intercellular CO₂ concentration showed a decreasing trend.The water use efficiency was first high and then low,and the highest was when irrigated 6 times a day.The contents of vitamin C,soluble protein,soluble sugar,soluble solid and flavonoids were the best for irrigation 8 times a day,and the quality was poor for irrigation 2 times.Under the condition of irrigation 10 times a day,the root volume of eggplant is the largest,the root zone solution EC value is low,the plant height is the highest,the growth is better and the yield is higher.The principal component analysis was used to evaluate the comprehensive score,and the results showed that the score was the highest for each eggplant plant irrigated 10 times a day.In conclusion,the optimal nutrient solution irrigation mode is using inorganic matrix perlite,1500 m L of nutrient solution per eggplant per day and 10 times of irrigation frequency under the closed circular tank culture system.