esponse of old Crested Wheat grass Stands to Nitrogen Fertilizer in Western North Dakota

M crested wheatgrass stands in western North Dakota were established 15 to 20 years ago. These fields are still used for hay and pasture, and many are still in excellent condition. One field at the Dickinson Experiment Station, seeded in 1938, has produced an average of 1,262 pounds of forage per acre (dry weight) over the past 12 years. However, there is good evidence that the productivity of these old stands may be improved by application of nitrogen fertilizer. Rogler* and his associates at the Northern Great Plains Field Station, Mandan, have shown that old, closedrilled stands of crested wheatgrass can be expected to show substantial yield responses to application of nitrogen fertilizer, when moisture conditions are favorable. Carter" found at Fargo the yield of crested wheatgrass hay was more than doubled by application of 100 pounds of nitrogen per acre. He points out that response of forage grasses to fertilizer applications depends on available soil moisture, and that increased -forage and seed production from fertilizer will be more variable in western than in eastern North Dakota. To determine the n a t u r e and magnitude of the response that might be expected f rom nitrogen applications to old crested wheatgrass stands in western North Dakota, a fertilizer trial was started at the Dickinson Experiment Station in 1951. E. B. Norum of the North Dakota Agricultural College soils department, aided in getting this trial started.