Plant performance in controlled environment agriculture, the effect of different ebb and flow irrigation intervals on Brassica oleracea and Lactuca sativa

Increasing productivity in controlled environment agriculture may decrease environmental footprint and increase profitability of food produced in a vertical farm. Irrigation may be a limiting factor when it comes to plant performance and relevant research is limited. This study aims to increase productivity of lettuce and kale in a vertical farm by finding what irrigation levels enable highest crop productivity. Crops were grown in stone wool substrate in an ebb and flow irrigation system under four different intervals (4, 15, 60, and 270 min). Results in fresh and dry weight indicate an optimal irrigation interval for lettuce between 5- and 15-min interval. This data is supported by mineral content of lettuce. No significant difference between these two smallest irrigation intervals can be found. For kale data is inconclusive and no optimal irrigation levels have been found. During the experiment airflow was hardest to control which may affected results