The Study On Controlled Release Technology For Carbon Dioxide Enrichment In Greenhouse

In this paper, reseashs on controlled release technology for carbon dioxide enrichment in greenhouse has been carried out. By the theoretical and experimental studying, the conclutions can be drawn as follows:(1) The optimized CO₂ enrichment technology should be divided into two stages to go on: firstly, CO₂ shoule be supplied by very heigh speed,make the CO2 density quickly reach 600¹500μmol-mol^-1; The later speed of CO₂ feed with crop photosynthesis consume speed coincide, maintain the best CO₂ density of crop growth.(2) According to crop photosynthesis, respiration as well as soil CO₂ release rate, the optimized CO₂ supply model and the CO₂ balanced model have been established, and a computer program was developed. With tomato production as example, parameters of optimized CO₂ supply have been calculated,result as the CO₂ release rate of initial stage must reach 58.35⁶8.49%, the stabilize speed must reach 9.80-15.20mgCO₂ ? m^-2 ? min^-1.(3) Based on above studies,a CO₂ controlled release technology was developed employing bicarbonate ammonium. Using releated model calculated, this technology promoted CO₂ density to 800μmol·mol^-1 more than,which completely satisfy CO₂ requirement of crop photosynthesis;(4) Using liquid fertilizer preparation technology, we can develop reaction liquid into the foliar fertilizer, so raise nutrition elements' utilization rate and fertilizer's economic benefits.