Skip to main content
ARS Home » Research » Publications at this Location » Publication #245192
Title: Effect of Previous Fall Precipitation on Mixed-Grass Prairie

Author
item Wiles, Lori
item Dunn, Gale
item TRLICA, MILTON - Colorado State University

Submitted to: Weed Science Society of America Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 2/7/2010
Publication Date: 2/7/2010
Citation: Wiles, L., Dunn, G.H., Trlica, M.J. 2010. Effect of Previous Fall Precipitation on Mixed-Grass Prairie. Weed Science Society of America Meeting Abstracts.

Interpretive Summary:

Technical Abstract: Precipitation accounts for much of the year-to-year variation in forage production. Prediction of forage growth early in the season from readily available information about precipitation would help with choosing stocking rates when drought reduces forage growth. Previously, models were identified to predict peak standing crop from total precipitation during April, May and June using data from mixed-grass prairies in Montana, North Dakota, and Wyoming. The goal of this research was to determine if the predictions with those models could be improved by including precipitation during the previous fall. Total precipitation in some combination of the months of September through November was evaluated with models relating variation in forage production from average production to variation in precipitation from long term averages. Two different models based on a rectangular hyperbola were used. The results indicate that knowing previous fall precipitation was below the long term average is valuable information for predicting forage growth. For two locations, North Dakota and Wyoming, variability in forage production was modeled more accurately based on spring precipitation and total precipitation in September and October compared to spring precipitation alone. Modeling with two forms of the hyperbolic model, corresponding to different hypotheses for the effect of precipitation during the previous year on forage production, may be helpful in identifying the factors and interactions that drive the variability among locations in the relationship between forage production and precipitation.