Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 23, 2009
Publication Date: N/A
Technical Abstract: The USDA-ARS Crop Systems and Global Change Laboratory (CSGCL), located at Beltsville, MD, maintains and operates 18 outdoor, natural sunlit plant growth chambers referred to as soil-plant-atmosphere research (SPAR) growth chambers. Each state-of-the-art SPAR chamber provides precise control over air temperature, day-time atmospheric carbon dioxide concentration, and humidity. Chambers are fully automated to measure crop canopy gas exchange including photosynthesis, respiration, and transpiration and facilitate study of source-sink relationships, root and canopy growth and development, assimilate partitioning, and various physiological responses to the growth environment. In order to address a new research initiative to quantify and model nutrient stress responses in corn and potato crops, a sophisticated micro-irrigation system was recently installed. Each SPAR chamber was retrofitted with a system of individually controlled drippers rated for a maximum flowrate of 1.5 liters per minute. The new system allows researchers to change the source of irrigation for each SPAR chamber (filtered tapwater, shared 1500 liter fertigation tank, or individual 80 liter tank), and maintains water pressure (414 kilopascals) to ensure uniform flowrate regardless of the selected dripper configuration for each chamber. Automatic control over timing and duration of supplied irrigation/fertigation is independently controlled for each SPAR chamber. This presentation focuses on the technical design and performance details of the new CSGCL SPAR facility micro-irrigation system and describes preliminary research studies with the new system.