To restore a degraded pasture of Brachiaria decumbens, located in São Carlos — SP, southeastern Brazil, under altitude tropical climate, an experiment was carried out to study
the effects of limestone, buried or not buried in the soil, and fertilizer use on mineral content and forage yield, after
3 years of treatment. Limestone and phosphorus were applied once, one month before starting. NK were applied after each cutting,
for fertilized plots, four to five times a year. Experimental design was a random block (100 m2), with 6 replications and 4 treatments. Each block received 4 t/ha of limestone, except the control. Forage samples were
collected 14 cm above soil surface. Instrumental neutron activation analysis (INAA) followed by gamma-ray spectrometry was
the analytical method used to determine the mineral contents. Dry matter yield was affected positively with liming when compared
with the limestone control, but the effect of limestone use was more pronounced with the concomitant use of NK fertilizer.
The contents of Ca, Cs, Fe, La, Mg, Rb, Sc, Sm and Th in forage were negatively affected with the NK use, perhaps due to a
dilution effect, while a reverse were observed for K, Cl, perhaps due to input of KCl, besides Br, Mn and Se. It seems that
limestone is not a key input to restore degraded tropical pastureland, grown on acid soils, when nitrogen is lacking. INAA
allowed the monitoring of some not routine elements that may be under observation to avoid potential plant nutritional disorders
in production systems with high limestone and fertilizer use.