Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 15, 2001
Publication Date: December 1, 2001
Citation: WILLIAMS, R.D., BARTHOLOMEW, P.W. SIMPLE PRECIPITATION MODELS AS DECISION AIDS FOR OUTREACH SPECIALISTS.. AGRONOMY ABSTRACTS. 2001. Abstract No. a03-williams150220-p. CD-ROM. Interpretive Summary: Abstract Only.
Technical Abstract: Overseeding and establishment of cool-season forages in either the fall or spring require sufficient rainfall to insure seed germination and seedling establishment. Given a window of opportunity for planting, what are the odds of having sufficient rainfall for crop establishment? Here we examine a simple rainfall model and 30 years of historical climate data to predict the probability of accumulation of 25 or 50 mm rainfall during specified periods in the fall and spring for 18 counties in Oklahoma. Fall scenarios considered accumulation of rainfall between September 15 and October 15 or October 31, or between October 1 and October 31. The spring scenario examined the period April 15 to May 15. The results appear to favor spring planting regardless of location. Probabilities for spring rainfall were greater than 0.94 for 25 mm, and greater than 0.75 for 50 mm of rainfall. From September 15 to October 15 probabilities of greater than 25 mm and less than 50 mm ranged between 0.75 and 0.88, while probabilities for greater than 50 mm rainfall ranged from 0.53 to 0.75. Extending the time period by two weeks to October 31 improved the odds slightly. Results from the October 1 to October 31 scenario were similar to the results for the September 15 to October 15 time-frame. Information gained from such simple models may help extension personnel to advise the best season for planting cool-season forages.