Production and nutritional quality of western ragweed seed in response to fertilization

Abstract

The importance of western ragweed (Ambrosia psilostachya) DC.) in the diet of bobwhites (Colinus virginianus Merr.) and their high dietary requirement for essential amino acids prompted us to explore the use of disking and fertilization (nitrogen and phosphorus) to improve its nutritional quality on deep, unfertile, sandy-soil rangelands in western Oklahoma. Fertilization (55 kg N ha-1, 56 kg P ha-1 as diammonium phosphate) of disk strips did not readily increase seed production of western ragweed. Fertilizer had no detectable effect on nutritional quality of seeds, which contained an average of 13% crude protein and 21% fat. Conflicting results reported on the effect of fertilizer on the quality of plant proteins within the literature could be attributable to differences of climate and soils, growth habits of different plant species, type and rates of fertilizers, and stages of maturity when plants are harvested for analysis.