Application of nitrogen (N) fertilizer and atrazine [6-chloro-N-ethyl-N'-(l-methylethyl)-1,3,5-triazine-2,4-diamine] have each increased grazeable forage on shortgrass prairie, but their effects are unknown when applied in combination. Therefore, a 9-year study was conducted to determine effects of N and atrazine applications on 1) herbage production, 2) steer gains, and 3) profitability of grazing on shortgrass prairie in north-central Colorado. Treatments were 1) untreated control, 2) atrazine applied at 1.1 kg ha-1 in the autumn of alternate years, 3) N applied at 22 kg ha-1 each autumn, and 4) N + atrazine at the rates specified above. Pastures were stocked at 21-41 (control), 27-54 (atrazine), 24-82 (N), or 18-84 (N + atrazine) cattle-days ha-1 during summer. Pastures were stocked with yearling steers 1979-1983 and yearling steers and spayed heifers 1984-1985, using put-and-take stocking. All treatments increased total October standing crop and blue grama (Bouteloua gracilis [H.B.K.] Lag. ex Griffiths) standing crop. Nitrogen increased cool-season grass and forb standing crops; atrazine nearly eliminated cool-season grasses but did not affect forbs. Under put-and-take stocking, atrazine and/or N appeared to increase stocking rate and gain/ha, but not average daily gain or average returns to land, labor, and management. Under optimum stocking rates and grazing strategies, N or atrazine but not both together might increase returns. The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information. Migrated from OJS platform August 2020
Scholarly peer-reviewed articles published by the Society for Range Management. Access articles on a rolling-window basis from vol. 1, 1948 up to 5 years from the current year. Formerly Journal of Range Management (JRM). More recent content is available by subscription from SRM.