Injury from Burning off Old Grass on Established Bluegrass Pastures 1

Bl~rning over pastures in the early spring is not only a common practice in some localities, but is quite generally recognized as being beneficial. Generally, it is regarded aa having a stimulating effect on the early spring growth of perennial pasture grasses. Empirical information indicates that such burning should be done while the ground is still frozen, although much of it is not done until after thawing when tl~e old grass may become sufficiently dry to burn readily. On March 9, 192 S, the writer burned the old accumulated grass of a bluegrass sod which had not been pastured the previous summer. The ground was still solidly frozen, but the grass burned very well, owing to extremely dry weather. The fire was extinguished along a certain line so that a contrast in the following growth between burned and unburned areas might be made. With the &dvent of warm growing weather, the burned area presented a very fresh, vigorous, green, lawn-like appearance, while in the unburned area, most of the early spring growth was hidden by the dry old grass which had accumulated during the previous summer. Observing this difference in appearanee, the foreman of the experimental farm burned on May ti, ~92 s, another area, leaving a rod strip unburned between this and the March 9th burning. On May ~th, the ground was completely thawed so that in the experiment there were three areas, one burned on March 9th, while the ground was frozen, a rod strip not burned at all, and an adjace.nt area burned on May ~th. It may be added that the May i ~th burning was made possible by the extreme drought which had not permitted much new spring growth in amongst the grass. Part of these areas were pastured in i925 and part were not pastured. During the early summer a very pronounced difference in tl~e rate of growth of the grass was readily observable. The differences became intensified during the fall. On the May 1 ith burning, the grass was very short and this area became badly ’infested with such common weeds as witch grass, r~gweed, and others. The area burned March 9th grew more vigorously and weeds were not so