Thursday, August 7, 2008

PS 56-41: Effect of mid-summer haying on early and late flowering prairie plants

Becky Begay, Helen M. Alexander, and Erin Questad. University of Kansas

Background/Question/Methods

Prairie hay meadows are biologically diverse and mid-summer haying is a common management practice in prairies. Haying may have differential effects on growth and reproduction of various species of prairie plants.  We looked at the effect of clipping on 8 prairie species, 4 early flowering and 4 late flowering. For each of the species, sixteen plants were chosen and half were randomly assigned to a clipping treatment and half to a control treatment. Plants were cut with a gas-powered trimmer to a 10 cm height. Measurements of plant height and the number of inflorescences were taken on all plants prior to clipping in July and in September.

Results/Conclusions For all species, clipped plants were smaller in September than the control plants. However the effects of clipping on growth and reproduction differed. For example, control plants of late flowering Salvia azurea and Lezpedeza capitata had increased in size over the summer, while clipped plants were reduced in size.  There was also an effect on reproduction for plants of early flowering species Amorpha canescens and Ratibida pinnata. We will examine whether the effects of clipping are still evident in a 2nd year. There is little information on the effect of haying on individual prairie species, especially non-grass species. The goal of our research is therefore to examine whether individual prairie species display differential growth and reproduction due to haying management practices.