Root Morphology and Forage Production of Highly Fertilizer Responsive Bermudagrass Genotypes.

In the process of developing new forage cultivars, selection is carried out under recommended or reduced fertilizer rates to produce nutrient efficient varieties. This is how current commercially available bermudagrass and stargrass varieties have been developed. However, in dairy operations, significant amounts of manure are produced every day that must be used or disposed. Usually dairy producers apply this manure to bermudagrass or stargrass pastures. This takes advantage of manure as a fertilizer but is also a way to dispose of this large amount of “waste.” The amount applied is restricted by the Nutrient Management Plan (NMP) to the amount of nutrients, especially nitrogen, removed by the pasture. Here we propose to develop a new variety of bermudagrass aimed at improving nutrient uptake. A series of experiments are being performed to achieve our goal: 1) almost 300 accessions were tested in three sites in Florida and Georgia, 2) selection was carried out for nitrogen content and yield, 3) a Mesocosm experiment was carried out to study the effect of selections under normal and high nutrient applications, 4) roots were sampled from field experiment for all selections, 5) a field experiment emulating the mesocosm experiment is currently being performed. In this work we will present the results of the steps 1 through 4.