INITIAL IMPACTS OF DIFFERENT FERTILIZERS ON IMPROVED EAST TEXAS EQUINE PASTURES

ABSTRACT

In Texas, approximately 1.6 million acres support an equine population exceeding 748,000 horses. This study assessed the effects of organic and inorganic fertilizer treatments on improved Bermudagrass (BG) and other vegetation (OTH) in overgrazed equine pastures at the Stephen F. Austin State University Equine Center. Treatments included equine manure (H), broiler poultry litter (P), and a commercial 13-13-13 fertilizer (C), with application rates based on pasture requirements.

Initial vegetation cover was evaluated using the Daubenmire cover class method in September 2024, followed by a 60-day undisturbed growing period. Final biomass (g/2ft² converted to lbs/ac) and percent cover measurements were collected in November 2024. The data was analyzed using ANOVA in R Studio (α = 0.10). Biomass analysis revealed significant differences in vegetation type across all pastures except Pasture 3, where no variables were statistically significant. In Pasture 2, poultry litter significantly reduced the biomass of OTH vegetation. Overall, BG exhibited greater biomass compared to OTH across all pastures.

Percent cover analysis demonstrated that OTH vegetation was significant across all pastures, with a significant interaction between H and OTH in Pasture 3 and the combined analysis, suggesting that horse manure promoted OTH vegetation cover. Economically, poultry litter was the most cost-effective treatment, while commercial fertilizer had the highest cost. Although statistical significance was limited, mean biomass and cover values suggested poultry litter improved BG growth, despite notable variability likely due to the small sample size. Further research may help refine biomass estimates and confirm treatment effects.