Greenhouse Production of Cucumbers
Sanchez-Guerrero, M.C., Lorenzo, P., Medrano, E., Baille, A. and Castilla, N. 2009. Effects of EC-based irrigation scheduling and CO2 enrichment on water use efficiency of a greenhouse cucumber crop. Agricultural Water Management 96: 429-436.
The total season-long yield of the cucumber crop was increased by 19% by the extra 100 ppm of CO2 supplied to it during daylight hours, while the overall water use efficiency of the CO2-enriched plants, based on the amount of water supplied to them, was about 40% higher.
The five Spanish researchers conclude their report by stating that their study "confirms the potential interest of using moderate CO2 enrichment strategies in greenhouses located in areas such as the Mediterranean basin, where the agricultural sector is facing scarce and declining water resources, and needs to drastically reduce the contamination due to fertilizer emission to ensure the sustainability of greenhouse production." And, of course, it demonstrates the significant benefits that may come to open-field agriculture, as the CO2 content of earth's atmosphere continues to rise.