Effects of Fertilization and Cutting Height on Yield and Persistence of Orchardgrass (Dactylis glomerata L.).

Orchardgrass is an important species for hay production in the Mid-Atlantic.  Recently, producers have noted a marked decline in the persistence of orchardgrass hay stands.  It has been hypothesized that this decreased persistence could be related to harvest management, pests, improper fertilization, or some combination thereof.  Two experiments were established in Virginia to evaluate orchardgrass under various fertilization and harvest regimes.  The objective of experiment 1 was to determine the yield, persistence, and disease rating of orchardgrass fertilized with N, K, and S.  The objective of experiment 2 was to determine yield and persistence of orchardgrass planted into soils with a range of soil test P and K values and harvested at two cutting heights.  Results from the 2013 season are as follows:  N and K fertilization in experiment 1 increased yields but no response to S fertilization was observed.  Leaves from plots fertilized with N showed a greater proportion of diseased area than did plots without N.  Experiment 2 showed poor orchardgrass establishment in plots with low soil test P and yield tended to be lower under low P and K fertilization.  Yield tended to be greater at lower cutting height during the first growing season.  Belowground processes will also be examined in these experiments, and persistence will be measured with data from future growing seasons. Fertilization, especially N and K, and proper harvest management should improve the yield and persistence of orchardgrass hay stands.