EVALUATION OF ROMAINE LETTUCE (LACTUCA SATIVA L. CV. PARRIS ISLAND) PRODUCTION UNDER AN ELEVATED CARBON DIOXIDE (CO2) GAS ENVIRONMENT GENERATED FROM COMPOST MATERIALS

Abstract

Composting is a process in which organic matter is biologically degraded leading to stabilized organic matter and waste gases such as carbon dioxide and ammonia. The CO2 emissions from the composting process can be used to supplement CO2 in controlled environment agriculture production. Partially composted feedstocks was evaluated for CO2 and NH3 emissions in a series of incubation experiments. The results indicated that the compost material had potential usage as a CO2 source for use in a controlled environment agricultural growing system. Romaine lettuce (Lactuca sativa L. cv. Parris Island) was grown under compost gas and pure CO2 gas enrichment in a hydroponic system. The mixed gas from compost material, after NH3 filtering had similar effects on lettuce growth as a pure CO2 enriched treatment, leading to increased lettuce biomass production, relative to plants under ambient conditions and increased total amount of nitrogen and carbon contents in the leaves.