Projects Selected for Funding in 2014
Estimating Groundwater Recharge Using the Oklahoma Mesonet
Tyson Ochsner, Chris Fiebrich, and Chris Neel
Oklahoma water resource managers need accurate information on groundwater recharge
rates to allow more effective water management and planning and to reduce groundwater
related conflicts, but no functional recharge monitoring network exists in Oklahoma,
or anywhere else to our knowledge. The statewide Oklahoma Mesonet provides a uniquely
rich set of long-term data on hydro-meteorological variables which are relevant for
recharge estimation, most notably soil moisture. When soil moisture, hydraulic conductivity,
and hydraulic gradient are known, drainage from the soil profile can be calculated
based on unsaturated flow theory (Nolan et al., 2007). Groundwater withdrawals that
exceed the rate of drainage from the soil profile are not sustainable in the long
term, unless the aquifer receives inflows from adjacent aquifers or surface water
bodies.
Comparison of Grain Sorghum and Corn Productivity under Limited Irrigation with Subsurface Drip
Jason G. Warren, Rick Kochenower, Jody Campiche, Rodney Jones, and Art Stoecker
Various sources can be cited to demonstrate the lower irrigation requirement for optimum
grain sorghum production compared to corn. For example, a study conducted at Garden
City, KS showed that sorghum irrigated with 7 or 2 inches of water produced average
yields of 122 to 117 bu, respectively, during the 4 year study. In contrast, irrigation
of corn at rates ranging from 12 to 3 inches produced yields ranging from 205 to 119
bushels (Klocke and Curri, 2009). This data demonstrates the lower water requirement
for grain sorghum under the given environment. However, these studies do not provide
representation of yield potential using recently developed sorghum genetics and management
practices. Recent analysis of sorghum variety trial data from the OSU Panhandle Research
and Extension Center shows that between 2009-2012 average sorghum yields of 145 bu/acre
were achieved with 10 inches of in season irrigation. This along with declining well
capacities and concerns about future restrictions on water availability require that
a detailed analysis of the yield potential for irrigated sorghum and its economics
relative to corn be conducted.
Increasing water yield and quality through redcedar removal and establishment of herbaceous biofuel feedstock production systems: Effect of vegetation on groundwater recharge in upland ecosystems
Chris Zou, Rod Will, Garey Fox, and Todd Halihan
Most studies of land conversion to bioenergy production have focused solely on surface
water and not groundwater. Changes in land use and vegetation cover can directly alter
groundwater recharge processes, especially in water limited semi-arid and subhumid
regions. Vegetation reduces groundwater recharge by either extracting groundwater
from the saturated zone or reducing rainfall reaching the groundwater table. Research
so far has focused mainly on the riparian zone where connectivity between the surface
and the alluvial aquifer is intuitive and the interaction can be rapid. However, over
90% of land surface is upland, and the effect on groundwater of changes in upland
vegetation cover such as conversion from redcedar woodland to herbaceous biofuel feedstock
production is poorly understood.