A PROTOCOL FOR DIFFERENTIATING HYDROLOGIC ZONES OF SOIL MOISTURE

Authors: Gish, Timothy; Walthall, Charles; Daughtry, Craig; Prueger, John

Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 4/30/2003
Publication Date: 11/2/2003
Citation: Gish, T.J., Walthall, C.L., Daughtry, C.S., Prueger, J.H. 2003. A Protocol for Differentiating Hydrologic Zones of Soil Moisture [CD-ROM]. Crop Science Society of America, Soil Science Society of America. Denver, Colorado: Agronomy Society of America.

Interpretive Summary:

Technical Abstract: Soil moisture influences pesticide persistence, volatilization, and leaching processes as well as controlling within field crop variability. Soil water dynamics is heavily influenced by landscape position, subsurface stratigraphy, and climatological interactions. Recently, a protocol based primarily on ground-penetrating successfully identified subsurface convergent flow pathways that influenced plant growth patterns in both wet and dry years. An index was developed using plant growth patterns from dramatically different climatological seasons to reduce the uncertainty associated with the GPR technique. Ground penetrating radar, soil moisture observations, and remote sensing techniques were initially used to verify the subsurface soil moisture index. Later, pesticide volatilization fluxes from two regions identified as being either negligibly or heavily influenced by subsurface soil moisture were monitored. Volatilization fluxes from the area identified as being heavily influenced by subsurface soil moisture were nearly twice that of the other site. This study suggests that the index may be useful for determining the degree of influence subsurface soil moisture has on chemical behavior and may also be an important tool for developing algorithms to differentiate crop management zones.