Monitoring and controlling of CO₂ concentrations in open top chambers for better understanding of plants response to elevated CO₂ levels

Abstract

The exponentially rising concentration of CO₂ in the atmosphere is one of the important changes, which effectively influences the productivity of agricultural crops. Innovative approaches for conducting long-term experiments on plants have been developed to investigate the growth and yield response of different plants to predicted elevated levels of CO₂. The accuracy of the results depends on the system adopted and its maintenance of the desired CO₂ levels with near natural conditions for other parameters. In one of such efforts, a system for continuous monitoring and maintaining the desired level of CO₂, temperature and relative humidity in open top chambers (OTCs) was developed. Carbon dioxide gas was supplied to the chambers and maintained at set levels using manifold gas regulators, pressure pipelines, solenoid valves, rotameters, sampler, pump, CO₂ analyzer, PC linked Program Logic Control (PLC) and Supervisory Control And Data Acquisition (SCADA). These OTCs are cost effective for meeting the requirements of field research on CO₂ enrichment.