Fertility of soils in the region of transamazonic highway. III. Fertilizer experiments
DOI:
https://doi.org/10.1590/S1678-3921.pab1977.v12.16792Keywords:
tropical soils, fertility, sorghum, response to mineral fertilization in Red-Yellow Podzolic and Reddish-Brown Lateritic Soils, pot experimentsAbstract
A greenhouse experiment was conducted to study the effect of N,P2O5, K2O and a mixture of Mg, S, Zn, B and Mo on the growth of sorghum in two sols occurring along the Transamazonic Highway. For the first soil - Red-Yellow Podzolic - it was verified the need of applications of N,P205 and K2O at the levels 207, 251 and 191 kg/ha, respectively. it was also found response to the mixture of Mg, S and microelements (Zn, B and Mo). Liming (2 ton/ha) without fertilizers had no effect in this soil. In the "Terra Roxa Estruturada Latossólica" (comprised in the former Reddish-Brown Lateritic Soils) which didn't have exchangeable aluminum, there was response to N, P2O5 and its interaction, with significant linear effect in the three cases. Potassium had no effect in the increase of production.
