Identification of simple mass balance models for plant growth - Towards food production on manned space missions

This paper presents a simple mass balance model for plant growth. This work is a first step in the development of a model intended to enable the prediction and control of a plant production chamber for MELiSSA, a regenerative life support system project developed by the ESA. Photosynthesis and respiration were selected as key reactions for biomass production. Considering these reactions, the model was developed using a mass balance approach. Reaction kinetics were chosen based on plant physiology and standard biochemical reaction knowledge. The identification and validation of yield and kinetic parameters were performed using data from lettuce and beet experiments in a closed plant chamber. The model adequately predicts lettuce growth, and predicts beet biomass and carbon dioxide flux well after an initial acclimation phase. The oxygen prediction could be improved and should be the subject of further study.