Use resources wisely: waste management and organic liquid fertilizer use in greenhouse production system

Interest in local and organic food production, waste management and sustainable food production in controlled environments are gaining interest. Significant amount of food is wasted in the US. Converting solid food waste into useful products has substantial economic, social and environmental benefits. Therefore, there is a need for technological advancement with innovative technology, solving community problems with local resources, and, ultimately, changing the way of thinking and management of waste, and using resources wisely. This study focused on evaluating the effects of the organic liquid fertilizer obtained from food waste, using a patented technology (WISErg Corp., WA, USA), on overall quantitative and qualitative yield of lettuce crop growing in a sand culture system in a high tunnel greenhouse system. A comparative study was conducted using inorganic fertilizer for production in the control greenhouse while organic liquid fertilizer was used in the treatment greenhouse for the production. The results showed that the fresh weight based yield data indicated no significant differences for all lettuce cultivars grown between the inorganic and organic fertilizer fed group plants. Bioactive content analysis for anthocyanin levels showed that they were slightly higher especially in the colored lettuce cultivars (i.e., 'Cherokee', 'Magenta' and 'Salanova Red Incised') in the organic liquid fertilizer fed group compared to fed with inorganic fertilizer. This preliminary study provided promising results for potential use of liquid organic fertilizer reducing the demand on inorganic fertilizers, improving waste management practices and using resources wisely in controlled environment food production system.