Uptake And Utilization Of Water And Fertilizer On Vegetable Plug Seedlings Under Ebb-and-flood Irrigation

Cucumber(Cucumis sativus L.cv.Zhongnong No.18),tomato(Lycopersicun esculentun Mill.cv.Zhangza No.105),pepper(Capsicum annuum L.cv.Zhongjiao No.6)and eggplant(Solanum melongena L.cv.Yuanza No.16)seedlings were used to investigate the supply,uptake and utilization of water and fertilizer under ebb-and-flood irrigation.This experiment verified the holding law of water and mineral elements,optimal nutrient solution concentration and nutrient use efficiency.This could provide the reference for promotion and application of vegetable plug seedlings under ebb-and flood irrigation.1.Three regular plug trays(50,72,128 cell),standard nutrient solution and three irrigation height(1,2,3 cm)were used to investigate relative water content,electrical conductivity and mineral elements content(N,P,K,Ca,Mg,Mn,Cu,Zn).The results showed that the relative water content,electrical conductivity and mineral elements content of substrate increased as the irrigation height increasing.When irrigation time is 15 minutes,the relative water content of substrate under 3 cm irrigation height was increased by 20.38%,16.78% and 18.40% compared with 1 cm irrigation height,respectively.The variation law of electrical conductivity and mineral elements content is similar to relative water content under different irrigation height.Furthermore,the smaller the cell,the quicker the uptake rate of water.For example,when irrigation time is 8 minutes,the relative water content of substrate in 128 plug tray is 74.7% under 2 cm irrigation height,the relative water content of substrate in 72 plug tray is 70.3%,the relative water content of substrate in 50 plug tray is only 67.9%.This experiment verified the holding law of water and fertilizer of substrate under ebb-and-flood irrigation.2.Cucumber(Cucumis sativus L.cv.Zhongnong No.18)seedlings were grown in two pattern cell from regular and abnormal plug tray to investigate the effects of cell pattern and nutrient solution concentration(×1,×0.5 and ×0.25)on cucumber plug seedling growth and mineral elements absorption under ebb and flow irrigation.The results showed that: The amount of mineral elements especially macro-element and chlorophyll content in cucumber plug seedlings were increased significantly followed nutrient solution concentration increase,such as N,P,K was increased by 102.6%-125.1%.Similarly,the seedling size and leaf area as well as fresh and dry weight increased with increasing nutrient solution concentration.The mineral element absorption and growth of cucumber plug seedling also were affected by cell pattern and the regular cell had better performance than abnormal.Finally,based on seedling health index optimal combination,i.e.,regular cell and Hoagland nutrient solution at ×1 concentration level,was obtained.3.Tomato(cv.Zhangza No.105),pepper(cv.Zhongjiao No.6),eggplant(cv.Yuanza No.16)and Hoagland nutrient solution were used to measure morphological indexes and the mineral elements use efficiency of seedlings under ebb-and-flood irrigation.The results showed that the size,stem diameter as well as fresh and dry weight of solanaceou vegetable seedlings reach the ideal value.By further analysis for mineral element uptake,We could get the results: for tomato seedlings,the K use efficiency is highest of 76.8% followed by N,P and Ca,the lowest one is Mg,only 27.5%.For pepper seedlings,the K use efficiency is highest of 83.0% followed by N,P and Mg,the lowest one is Ca,only 33.2%.For eggplant seedlings,the K use efficiency is highest of 56.6% followed by N,P and Ca,the lowest one is Mg,only 16.1%.