Neutron Physics Considerations in Moisture Probe Design
Neutron physics can be used to characterize most of the know behavior of neutrons in the soil. Scattering, absorption and slowing down are the principal processes affecting moisture probe...
Factors Affecting Neutron Gauge Calibration
Neutron gauge characteristics and soil chemistry affect gauge calibration. External factors also influence gauge calibration and should be considered in the calibration procedure. Gauge...
Access Tube Characteristics and Neutron Meter Calibration
Neutron meter calibration was found to be influenced by material type, thickness and size of access tube. Meter counts were decreased by an average of 15% for a 20% increase in tube diameter...
Relationship of Soil Type and Chemicals to the Calibration of Neutron Meters
Theory of neutron scattering and moderation in matter explains many of the characteristics of calibration curves of neutron moisture probes. Characteristics include effect of atomic species...
Using Neutron Probes to Aid Irrigation Scheduling
Neutron soil moisture measurements are used to supplement irrigation forecasts on the 60,000 acre sprinkler-irrigated Navajo Indian Irrigation Project (NIIP). Weekly irrigation forecasts...
An Assessment of Input Variables to the Penman-Monteith Equation Using Canopy Reflectance Measurements
Observing the form of the Penman-J.L. Monteith equation, it can be seen that several terms could be potentially estimated from remotely sensed data. These include: net radiation, canopy...
Management Practice Effects on Water Quality
An array of resource conservation and water quality issues are providing research challenges and opportunities in soil and water, irrigation, and drainage. The key to addressing these...
Field Calibration of Neutron Gauges: SCS Method
Field calibration of neutron gauges is easy and requires very little time under normal circumstances. Special soil sampling equipment is required that can be fabricated by most machine...
Comparison of ET Measured with Neutron Moisture Meters and Weighing Lysimeters
The neutron moisture meter (N.M.) method of determining crop water use is frequently used in research and irrigated agriculture. This study was conducted to compare crop evapotranspiration...
Application of Neutron Soil Surface Water Monitoring for Plant Establishment
Soil surface water content measurements are tedious and time consuming, and to improve on such tasks, a neutron surface moisture probe was modified by using cadmium shielding. This prevented...
Practical Approaches Used in Neutron Meter Moisture Monitoring
This paper describes a practical, appropriate methodology for utilizing neutron meter soil moisture measurements to provide irrigation management information to farmers. A neutron meter...
Neutron Meters in Statewide Irrigation Programs
These programs have ranged from University demonstrations of new technologies on through completely locally funded and operated programs. The most significant interest has been from those...
Computation of Unsaturated Soil Parameters Using Upward Infiltration Empirical Data
The relationship between soil moisture content and hydraulic conductivity with the soil tension be defined to simulate unsaturated flow in a porous media. Direct measurements of these...
Impact of Agriculture on Ground-Water Quality on the Delmarva Peninsula
Both pesticides and nitrates have been detected in the ground water on the Delmarva Peninsula. Highest nitrate concentrations have been found on well-drained soils. Poultry manure is one...
Soil Water Movement in Glacial Till: A Case Study in Central South Dakota
Between 1985 and 1987, the CENDAK Drainage Steering Committee conducted several investigations to assess the drainage needs for a proposed large-scale irrigation project in central South...
Deep Percolation, Drainage and Water Quality
The purpose of this study is to illustrate and and qualitatively describe results of steady and transient numerical simulations examining the influence of drain spacing and depth on shallow...
Bottom Plugging Dynamics in Recharge Basins
The Orange County Water District is investigating the reasons why percolation rates in deep recharge basins rapidly decrease. The interrelationship between microbiological activities in...
Effect of Water Depth and Groundwater Table on Infiltration from Recharge Basins
The actual effect of water depth on infiltration depends on the depth to groundwater and on whether the wetted perimeter of the basin is clean or covered by a clogging layer of fine particles...
Effect of Saline Irrigation Water on Tree Growth
A random block experiment using three types of soil, five different qualities of irrigation water, and three popular windbreak trees was conducted to measure the effects of soil type and...
Prognosis on Managing Trace Elements
Management options assessed for trace elements discharged from irrigated lands include source control, drainwater reuse, drainwater treatment and removal of contaminants, disposal, and...
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