|Wu, Joan - WASHINGTON STATE UNIV|
|Dun, S - WASHINGTON STATE UNIV|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: June 1, 2003
Publication Date: November 1, 2003
Citation: Wu, J., Dun, S., Huggins, D.R. 2003. Optimizing planting time based on shaw-simulated seed-zone moisture and temperature [abstract]. Agronomy Abstracts. Paper no. S01-wu942898-oral. Technical Abstract: Adequate maintenance of seed-zone moisture is key to successful establishment of fall-sown crops in the Pacific Northwest (PNW) dryland region where early planting is important to increase the chance of greater yields. PNW features dry summers with little to no rainfall. Major factors affecting fall-season seed-zone moisture are over-winter soil water storage and spring-season precipitation. These factors, however, have a significant year-to-year variation and are difficult to evaluate without using computer models. In addition, these factors can hardly be evaluated independently of the crop rotation, tillage, and residue management history. The goal of this study is to determine optimal seeding time for selected winter crops under different climatic conditions and cultural practices using the SHAW (Simultaneous Heat and Water) model. SHAW simulates interrelated heat, water, and solute movement through the vegetative cover, residue, snow, and soil system, and outputs soil moisture and temperature profiles that are most crucial for predicting seed germination and emergence. In this study, SHAW will be used to determine optimum planting times for three winter crops, wheat, pea and lentil, under different cropping practices. Additionally, seeding time as affected by different climatic conditions (rainfall level, temperature) will also be evaluated.