A greenhouse experiment was carried out at the University of Santa Maria, RS, Brazil, to evaluate the effect of incubation time ofcoarse granulated magnesian thermophosphate in the soil, preceding the seeding, on phosphorus availability for bahia grass (Paspaium notatum Flugge var. saurae) and evaluate the effect ofindigenous arbuscular mycorrhizal fungi (AMf) in the phosphorus recover by bahia grass. The treatments were randomized with four replications, forming incomplete factorial design (3X2X2+8), three incubation times in umid soil of the coarse granulated magnesian thermophosphate preceding the seeding (0,100 and 200 days); twopHvalues (4,8 and liming Io pH 6.0); and with or without inoculation wilh AMf: the contrais Ireatments were without phosphorus and with concentrated superphosphate, both with or wilhoul inoculation and with or without liming. Phosphorus was addedat the rate of l00mg P2O5 kg-1 of soil. It was observed that (a) the thermophosphate incubation time, preceding the seeding of the bahia grass, increased its solubility in soil, however phosphorus availability did not increase as phosphorus availability from concentrated superphosphate; and (b) soil inoculation wilh indigenous AMf increased bahia grass dry matter yield and phosphorus uptake oníy whenplants were submitted to nutritional stress, despite the low colonization micorrhizae.
coarse magnesian thermophosphate; phosphates; phosphorus recovery; bahia grass; indigenous mycorrhizal fungi
