The Water Mangement Research Of Pakchoi Plug Cultivation Based On Tidal Irrigation

This paper focus the drawbacks exists in current domestic greenhousewith traditional irrigation methods, introduces the foreign advancedirrigation technique-tidal irrigation, which use Pakchoi as researchmaterial and substrate water content as the main basis for studying theeffect of rehydration limit, irrigation volume and plug immersion time onPakchoi growth and nitrogen nutrient leaching deeply. The main findingsare as follows:(1) Through compared the change regularity of plug weight weestablished the correlation between plug weight and substrate watercontent by taking no-sowing plug and sowing plug as treatments, Theresults showed that there was no significant difference in plug weightreduction of the two treatments, And there was a significant linear relationbetween the plug weight and substrate water content (R2=0.8219) andbetween the plug weight and substrate relative humidity (R2=0.9773).(2) The rehydration limit test by setting different rehydration time (24hours,48hours,72hours) to control substrate moisture to study the effectof irrigation lower limit on photosynthesis and the growth conditions ofPakchoi, the results indicate that substrate water content at about50%asthe rehydration lower limit, the growth and physiological indexes areoptimal for Pakchoi.(3) Based on the two previous experiments, through the "eco-meter" monitor substrate water content, control the rehydration limit at about50%of substrate water content, set different irrigation amount (100%ET,90%ET,80%ET,70%ET), studying the effect of irrigation volume on thegrowth of Pakchoi, conclude that the irrigation volume of both100%and90%ET are optimal for the growth of Pakchoi.(4) On the basis of those experiments, by setting different plugimmersion time (10s,10min,30min,60min, throughout the growingseason) to explore it’s effect on Pakchoi growth and nutrient leaching. Theresults showed that with the prolonged of immersion time the nitrogenleaching in substrate was no significant difference, but under the treatmentof entire growing season the Pakchoi growth、biomass and the chlorophyllcontent are the highest.This paper provides technical guidance and theoretical basis foroptimizing tidal irrigation system of domestic greenhouse. The researchmeets the needs of tidal irrigation management system in greenhouse, hassome certain value in appliment.