ARS | Publication request: Mathematical simulation of soil microclimate conditions for predicting weed seed germination

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: December 14, 2006
Publication Date: December 14, 2006
Repository URL: http://ars.usda.gov/SP2UserFiles/Place/36450000/Products-Reprints/2006/1371.pdf
Citation: Spokas, K.A., Forcella, F. 2006. Mathematical simulation of soil microclimate conditions for predicting weed seed germination [abstract][CD-ROM]. North Central Weed Science Society Proceedings. 61:89.

Technical Abstract: Microclimate-based models for weed seed emergence are in the initial phases of development. The major driving forces of weed seed germination in the soil environment are temperature and soil moisture content. In the past these quantities have been measured at a single point (e.g., 5 cm). However, these variables fluctuate as a function of depth and time. Therefore, in order to improve weed emergence prediction, the ability to simulate soil temperature and moisture at 1-cm increments through the soil profile as a function of time is needed. In order to accomplish this task, a newly integrated user-friendly soil moisture and temperature model has been developed in JAVA. This model builds upon prior heat and moisture transport models but provides embedded empirical models to estimate fundamental physical parameters (e.g., thermal conductivity, unsaturated conductivity). These physical properties are not typically measured at a field site for weed emergence studies. These previously published empirical models require soil texture and organic matter content as input parameters in order to estimate other required parameters for soil moisture and temperature modeling. This estimation of soil physical constants by soil pedotransfer functions allow for a simplified user interface while not sacrificing theoretical modeling accuracy.