Effects of pasture-applied biosolids on forage and soil concentrations over a grazing season in North Florida. I. Macrominerals, crude protein, and in vitro digestibility
Me. Tiffany et al., Effects of pasture-applied biosolids on forage and soil concentrations over a grazing season in North Florida. I. Macrominerals, crude protein, and in vitro digestibility, COMM SOIL S, 31(1-2), 2000, pp. 201-213
The rationale for this experiment was to determine forage nutrient concentr
ations as affected by biosolids fertilization. We studied the effects of si
ngle applications of two exceptional quality biosolids to bahiagrass (Paspa
lum notatum) pasture with regard to satisfying beef cattle nutrient require
ments. Twenty-five 0.8-ha pastures were divided into five blocks. Two bioso
lids were applied as normal and double agronomic rates. The control plot re
ceived NH4NO3. Forages were analyzed for calcium (Ca), phosphorus (P), magn
esium (Mg), potassium (K), sodium (Na), crude protein (CP), and in vitro or
ganic matter digestibility (IVOMD), and soils were analyzed for Mehlich I e
xtractable Ca, P, Mg, and K. Single (agronomic or twice this) applications
of biosolids to pastures had little effect on Ca, P, Na, and K forage conce
ntrations, but forage Mg was elevated in several treatments late in the sea
son. Crude protein concentrations were elevated above the control for all b
iosolids treatments late in the season, whereas only small differences were
observed at early sampling times. Trends were similar for IVOMD. In genera
l, all treatments were associated with soils with adequate Ca, P, and Mg co
ncentrations, while soil K was uniformly low. In relation to grazing beef c
attle requirements, all treatments resulted in generally adequate forage le
vels of Ca, P, Mg, K, CP, and IVOMD, however, Na (<0.06%) was deficient.