Effect of soil water, nitrogen, and growing degree-days on morphological development of crested and western wheatgrass.

Frank, A.B.
Ries, R.E.
Society for Range Management
Publication Year: 
Production of total forage dry matter is mainly a function of available soil water and soil nitrogen (N), whereas plant morphological development from spring greenup to anthesis is primarily controlled by air temperature. There is a lack of information on effects of soil water and soil N on plant morphologIca development. A study was conducted in a rain-out shelter at Mandan, North Dakota, over a 3-year period to determine the effect of 2 fertilizer N rates (11 and 110 kg N/ha) and 3 rates of applied water (50,100, and 150% of long term April-November rainfall at Mandan, North Dakota) on morphological development of initial spring growth and fall regrowth of crested wheatgrass [Agropyron desertorum (Fisch.) Schult] and western wheatgrass [Pascopyrum smithii Rydb, (Love)]. Regression analysis of plant development stage with accumulated growing degree-days (GDD) was linear for both initial and regrowth forage. There were no differences in rate of plant development for the 3 rates of applied water or the 2 rates of N fertilizer. Initial growth forage of crested and western wheat- grass required 82 and 98 GDD to produce a leaf, respectively. Regrowth forage of crested wheatgrass required 372 and western wheatgrass 135 more GDD than iuitial growth to produce a leaf. These data confbm that plants develop primarily in response to air temperature and not added water or N, which enhances the utility of using the accumulation of GDD for predicting develop ment of crested and western wheatgrass under different growing conditions. This information will be useful for predicting plant development of these species in growth models and for farmers and ranchers in predicting grazing readiness.
Name of Journal: 
Journal of Range Management
257 - 260
Document Type: 
Journal Issue/Article
Society for Range Management

Rangeland Ecology & Management (formerly the Journal of Range Management) serves as a forum for the presentation and discussion of facts, ideas, and philosophies pertaining to the study, management, ecology, and use of rangelands and their resources. The journal is peer-reviewed and provides international exchange of scholarly research and information among persons interested in rangelands. The Global Rangelands collection includes REM content up to 5 years from the current year. More recent content is available by subscription from BioOne and the Society for Range Management, and may be available at your local university library.
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