Yield and Protein Content of Sandyland Range Forages as Affected by Three Nitrogen Fertilizers

Abstract

A west Texas sandyland range site was fertilized with two rates, (30 and 60 kg/ha of actual N) of ammonium nitrate (AN), ammonium sulfate (AS) and ammonium phosphate-sulfate (APS) on June 2, 1972. Yield samples taken in mid-August showed all fertilizer treatments to significantly increase total yields. The 60 kg/ha of N treatments of AS and APS produced more herbage than all other fertilizer treatments. Climax decreasers on the site, little bluestem (Schizachyrium scoparium) and sideoats grama (Bouteloua curtipendula), showed less yield response to fertilization than increaser and invader grasses. Crude protein analysis of leaf tissue showed the grasses of the control (ON) to contain significantly less and the grasses treated with 60 kg/ha of N as AN to contain more protein than other treatments. Sulfur appears to be more important than phosphorus in increasing yields on this site. Also, range condition should be at least high fair before fertilizer is applied to minimize competition between the desirable and invader plants.