Accession Number:

ADA289972

Title:

Meterological Effects on Soil Mositure and Crop Yield as Determined From the Soybean Crop Simulator: GLYCIM.

Descriptive Note:

Master's thesis,

Corporate Author:

PENNSYLVANIA STATE UNIV STATE COLLEGE DEPT OF METEOROLOGY

Personal Author(s):

• Di Rienzo, Stephen N.

Report Date:

1994-12-01

Pagination or Media Count:

79.0

Abstract:

Estimation of near surface soil moisture availability is of great importance to meteorologists and agriculturists. Potential benefits from knowing the soil volumetric water content include healthier crops, savings in water and money, and reduced leaching of hazardous chemicals into groundwater supplies. Many methods of estimating soil moisture have been developed. Devices to measure volumetric water content include tensiometers, porous electrical resistance blocks, neutron scatterers, Time Domain Reflectors TDRs, and capacitance probes. Meteorologically driven computer models have also been constructed to estimate the soil volumetric water content. Computer crop simulators must also estimate soil moisture for the plants themselves as well as the nutrient content and flow in the soil. This thesis discusses some problems in the soil moisture module of the soybean crop simulator GLYCIM. Initial model calculations are compared to a proven soil hydrology model. Improvements were made to the soil moisture module of GLYCIM so a more accurate estimation of soil volumetric water content and nutrients in the soil are calculated and available to plants in the model. Soil volumetric water content was then compared to the soil hydrology model for verification and differences were explained. Sensitivity tests were then carried out on GLYCIM to see which meteorological conditions are most important to soil volumetric water content as calculated by the model and also to crop yield as forecast by GLYCIM. Maximum probable error for soil volumetric water content and crop yield were calculated. -BKA

Descriptors:

• *AGRICULTURAL CHEMISTRY
• *MOISTURE CONTENT
• *SOIL MECHANICS
• *SOYBEANS
• COMPUTER PROGRAMS
• COMPUTERIZED SIMULATION
• ESTIMATES
• EVAPORATION
• FARM CROPS
• FERTILIZERS
• GRIDS
• GROUND WATER
• HAZARDOUS MATERIALS
• HYDROLOGY
• IRRIGATION SYSTEMS
• LEACHING
• METEOROLOGICAL DATA
• MODULAR CONSTRUCTION
• NUTRIENTS
• PLANT GROWTH
• PRECIPITATION
• RAINFALL
• SENSITIVITY
• SOIL MODELS
• SOLAR RADIATION
• TEMPERATURE GRADIENTS
• TENSIOMETERS
• TEST METHODS
• THESES
• TRANSPIRATION
• VEGETATION
• VOLUMETRIC ANALYSIS
• WET BULB TEMPERATURE
• WIND VELOCITY
• YIELD

Subject Categories:

• Agricultural Chemistry
• Meteorology
• Physical Chemistry
• Soil Mechanics
• Agronomy, Horticulture and Aquiculture

Distribution Statement:

APPROVED FOR PUBLIC RELEASE