Abstract
Forage-based beef cattle operations are prevalent across the southeastern United States. However, with inflated input costs related to inorganic fertilizer, economic cattle production is challenging. One management decision under consideration in these circumstances is the choice of investment in inorganic fertilizer for pastures for supplemental feed for cattle. The objective of the study was to determine the effects of byproduct supplementation on pasture health, soil health, and soil fertility. We hypothesized that byproduct supplementation of stocker steers at increased levels would achieve substitution effects, becoming a source of feedthrough fertilization for pasture nutrient cycling. Stocker steers (n = 60) were used in a put-and-take grazing and supplementation experiment, arranged in a generalized complete block design across two locations. Treatments included a 0.5 or 1.0% BW supplemental feed (SUP0.5 or SUP1.0, respectively), interseeded red clover (CLOV), or a negative control (tall fescue pasture only; CON). Forage allowance was targeted at 1.5 kg DM/kg BW, and steers grazed pastures for approximately 84 d. There was no effect of treatment (P ≥ 0.10) on forage mass or nutritive value, nor was there an effect of treatment for (P ≥ 0.22) for soil pH, OM, N, P, K, or microminerals. Results are interpreted to mean that, at least on the one-year scale of this dataset, supplemental feeding may not offset chemical fertilizer inputs, though partial budgets indicated increased revenue.