Methods in Determining Crop Water Usage
A study was conducted to evaluate different methods of measuring soil moisture and crop water usage in Southwest Kansas. Soil moisture readings taken by the neutron gauge were verified...

Measurement Systems in the Hapex-Mobilhy Regional Evapotranspiration Experiment
The HAPEX-MOBILHY (Hydrologic-Atmospheric Pilot Experiment - Modelisation du Bilan Hydrique) regional evapotranspiration experiment was conducted in the south-west of France during the...

Methods for Determining Actual Evapotranspiration in Plots
The major methods used at INRA since 1965 for determining actual evapotranspiration (AET) in plots are reviewed in this paper. These procedures involve either direct determination (weighing...

Pesticide and Nitrate Movement Under Conservation and Conventional Tilled Plots
Carbofuran, alachlor, atrazine, nitrate and bromide (a tracer) were applied to plots with conventional and conservation tillage. During the early part of the growing season the conservation...

Theory and Operation of French Energy Balance, Bowen Ratio and Micro-Meteorology Instrumentation
The Penman formula for potential evapotranspiration (ETp) and the Energy Balance Method for actual evapotranspiration (ETr) provide information on evapotranspiration rates. Examination...

A Portable Bowen Ratio System for ET Measurements
The AZET system developed at the University of Arizona is designed to measure evapotranspiration (ET) in arid zone environments, using the Bowen ratio model. The system consists of a set...

Bulk Stomatal Resistance in Operational Estimates of Evapotranspiration
General relationships for estimating canopy or bulk stomatal resistance and aerodynamic resistances of grass and alfalfa reference crops for use in the Penman-J.L. Monteith equation are...

Near-Real Time Weather Information for Irrigation Management in Arizona
The Arizona Meteorological Network (AZMET) is a near-real time ag-weather information system for Arizona. A single personal computer running inexpensive bulletin board software controls...

Canvas Covered Bellani Plate Atmometer
Crop water use information is essential for sound water management and conservation in irrigated agriculture. Many water management technologies are often inapplicable until accurate and...

Crop Irrigation Requirement Model for Utah
Crop irrigation requirements vary greatly across Utah's wide range of climatic conditions. About 40 electronic weather stations have been established in areas representing...

Irrigation Scheduling Using Voice Synthesis, the Next Logical Step
An irrigation management program sponsored by the Raft River Electric Cooperative in Malta, Idaho, provided directly measured soil moisture data to selected irrigators each week during...

Use of the Penman Equation in Inter-Mountain Valleys
H.L. Penman equation as well as the J.L. Monteith version of this equation were compared under the advective conditions of the Grand Valley of Colorado. The wind function in the general...

Use Requirements for Bowen Ratio and Eddy Correlation Determination of Evapotranspiration
Reduced costs and complexity are encouraging more operational use of eddy correlation (EC) and energy balance Bowen ratio (EBBR) instrumentation for estimating evapotranspiration. Often...

Large Scale Evapotranspiration from Remotely Sensed Surface Temperature
Large scale evapotranspiration requires a blend of ground-based and remotely sensed data. To evaluate the utility of the extension from a small to a large scale, studies were conducted...

System Scheduling for Large Farming Operations
Irrigation scheduling uses evapotranspiration data to recommend the time and amount of the next irrigation on a field by field basis. System scheduling minimizes the cost of water deliveries...

Thermodynamic Factors in Evapotranspiration
Many of the methods discussed in this paper are refinements of procedures presented in the report 'Consumptive Use of Water and Irrigation Water Requirements'...

Calibration of an Evapotranspiration Model Using Eddy Correlation Methods
An evapotranspiration (ET) prediction model was developed by calibrating the H. L. Penman equation for an alfalfa reference crop in the southwestern Oklahoma region. Evaporative flux for...

Dormant Season Evapotranspiration in Alfalfa
Weekly values of maximum temperature, minimum temperature, and solar radiation were examined for their effect upon weekly dormant season evapotranspiration (ETdorm) in perennial alfalfa....

Adding a Climatic Interface to Electronic Irrigation Controllers
Automated irrigation systems have traditionally relied on a time based controller set to operate the irrigation system for a specific duration and frequency. To determine the duration...

T Measurements for Irrigation of Sweet Corn
Commonly used scheduling methods are based on a water balance approach where evapotranspiration (ET) must be either estimated from climatic data or by soil water depletion measurements....

 

 

 

 

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