A Greenhouse Mesocosm System for Integrated Environmental Sensing, Root
Phenotyping, and New Sensor Development
Current methods of root sampling typically only obtain small or
incomplete sections of root systems and do not capture their true
complexity. To facilitate the visualization and analysis of entire, full
sized root systems of crop plants, mesocosm growth containers were
developed with an internal volume of 45 ft3 (1.27 m3). Mesocosms allow
for unconstrained root growth, excavation and preservation of
3-dimensional RSA, and modularity that facilitates the use of a variety
of sensors. Sensors arrays monitoring matric potential, temperature and
CO2 levels are buried in a grid formation at depths of 1.25, 2.75, &
4.25 ft to assess environmental fluxes at regular intervals.
Additionally, 3-dimensional water availability can be measured using ERT
inside of root mesocosms. Methods of 3D data visualization of fluxes
were developed to allow for comparison with root architectural traits.
Following harvest, the recovered root system can be digitally
reconstructed through photogrammetry, which is an inexpensive method
requiring only an appropriate studio space and a digital camera. Initial
metrics inferred from the 3D models include root system biomass
(occupied voxels), volume, flatness, convex hull volume and solidity
with depth. Root systems are finally dissected and biomass measurements
are made in a 3-dimensional matrix of the growth zone, while the crown
is saved for X-ray CT analysis.