SOIL AND WATER MANAGEMENT RESEARCH UNIT

Dr. Terry A. Howell, P.E.
Research Leader (Agricultural Engineer)
(806) 356-5746
terry.howell@ars.usda.gov

Efficient use of water in irrigated agriculture:

• Sprinkler irrigation (center pivots, LEPA, spray heads, chemigation)
• Microirrigation (surface drip and subsurface drip irrigation of row crops)
• Evapotranspiration (energy balance, water balance)
• Lysimeters
• Irrigation Scheduling (models, water management)
• Crop Growth Models (yield, development, ET, etc.)
• Micrometeorology
• Weather Networks
• Water Quality (drainage, erosion from irrigated lands)

Efficient use of water in irrigated agriculture:

• Center Pivot Automation
• Precision Irrigation Feedback and Control
• Time-Temperature_Threshold (TTT) Method of Irrigation Scheduling
• Canopy Temperature Based Water Stress Indicies
• Irrigation efficiency

Efficient use of water in dryland agriculture:

• Residue Management for Soil and Water Conservation
• Dryland Crop Rotations and Sequences
• Integrated Livestock and Row Crop Production Systems
• Computer Crop Growth Modeling
• Rain Infiltration and Field Hydrology

Efficient use of water in irrigated agriculture:

• Remote sensing (regional, farm, and site-specific crop management)
• Evapotranspiration (energy balance, water balance)
• Irrigation scheduling (models, water management)
• Lysimeters
• Subsurface drip irrigation
• Mechanical-move irrigation systems
• Site specific irrigation system design for precision agriculture

Efficient use of water in irrigated agriculture:

• Evapotranspiration (energy balance, water balance)
• Lysimeters
• Irrigation Scheduling (models, water management)
• Weather Networks

Efficient use of water in irrigated agriculture:

• Sprinkler irrigation (center pivots, LEPA, spray heads)
• Surface Irrigation Management (deficit irrigation)
• Evapotranspiration (energy balance, water balance)
• Remote Sensing
• Lysimeters
• Irrigation Scheduling (models, water management)
• Weather Networks

Efficient use of water in irrigated agriculture:

• Energy and Water Balances and Fluxes in the Soil-Plant-Atmosphere Continuum
• Irrigation Effects on Surface Energy Balance and Evaporative Losses (Sprinkler and Microirrigation)
• Soil Physical Property Effects on Plant Water Use
• Irrigation Scheduling
• Lysimeters for Measurement of ET and Water Quality
• Irrigation Scheduling (models, water management)
• Soil Water Measurement Methods (time domain reflectometry, neutron scattering, frequency domain, coring, etc.)
• Weather Networks
• Soil Physical Property Measurement Methods (tension and positive head infiltrometry, desorption methods)

Efficient use of water and nutrients in dryland agriculture:

• Influence of soil structure on water flow and solute transport
• Methods for the measurement of soil hydraulic properties
• Influence of soil physical properties on infiltration and water balance
• Nutrient management strategies for land application of stockpiled manure to dryland crops
• Phosphorous loading and transport on agricultural soils
• Influence of tillage and cropping systems on soil properties
• Use of the numerical method of lines to solve water, heat, and solute transport PDE's

Efficient use of water in irrigated agriculture:

• Plant Response to Water Stress
• Plant-Soil-Water Interactions
• Plant-Water Relations Measurements (transpiration, photosynthesis, leaf water relations)
• Evapotranspiration Partitioning (evaporation, E, and transpiration, T)
• Lysimeters for Measurement of ET
• Micrometeorological Measurements

Dr. Jose L. Chavez
Agricultural Engineer
(806) 356-5704
jose.chavez@ars.usda.gov

RESEARCH INTERESTS

Efficient use of water in irrigated and dryland agriculture:

• Improvement of agricultural water management
• Regional evapotranspiration (energy balance)
• Remote sensing and GIS applications for efficient water management
• Irrigation systems efficiency
• Precision irrigation (site-specific irrigation)
• Stream flow prediction

Efficient use of water in irrigated and dryland agriculture:

• Hydrologic Modeling (surface and ground water)
• Regional Water Use Budget
• Evapotranspiration (ET)
• GIS and Remote sensing (Rainfall estimation, ET and Crop Residue Cover Mapping)
• Crop Residue Management for Soil and Water Conservation
• Water Quality (Drainage, soil and nutrient losses)
• Precision Farming