Ways and means to minimize the ill effects of drought on black grama ranges

TitleWays and means to minimize the ill effects of drought on black grama ranges
Publication TypeReport
Year of Publication1939
AuthorsCanfield R.H.
Document NumberResearch Note 82
Date Published1939
InstitutionUSDA, Forest Service, Southwest Forest and Range Experimental Range Station
Keywordsblack grama, drought, effects, research notes
AbstractBlack grama ranges of southern New Mexico and adjacent portions of Arizona and Texas have the largely unmerited reputation of being excessively vulnerable to drought. Actually, a complete failure of the forage crop is as rare here as is the complete failure of crops in regions of higher rainfall. Climatic data support this statement and provide the best index to the frequency of lean years. Long-time precipitation records taken at the Jornada Experimental Range and supporting experience indicate that each 10-year period may be expected to include 1 year of drought and 2 or more critically dry years. During these dry years the forage growth is far below that of the average year. Forage estimates and grazing capacity figures indicate that the feed supply will vary 60 percent or more between good and poor years. With complete annual use, the current forage crop cannot always be depended on year in and year out to support an unvarying number of cattle. Clearly, if sustained grazing capacity is to be maintained, the feed produced in drought years must be supplemented in some manner.