On-line version ISSN 1678-992X
MOREIRA, A et al. AVALIAÇÃO DA DISPONIBILIDADE DO FÓSFORO NO SOLO POR MÉTODOS ISOTÓPICO, QUÍMICOS E BIOLÓGICO. Sci. agric. [online]. 1997, vol.54, n.1-2, pp. 78-84. ISSN 1678-992X. http://dx.doi.org/10.1590/S0103-90161997000100011.
An experiment was carried out in greenhouse with the objective of evaluating soil P by chemical (extraction by Bray 1, Mehlich 1, Mehlich 3 and resin), isotopic (E value) and biological (dry matter production of rice plants) methods. A Red Yellow Latossol (dystrophic) was used. The experimental design was a completely randomized 4x3: 4 rates of P (0, 50, 100 and 200 mg kg-1), 3 thermophosphate sources (Yoorin MC, Yoorin MG and Yoorin semi finished) and triple superphosphate (100 mg kg-1) with three replicates. Main conclusions were: the best correlations were found between either dry matter or P taken up with Mehlich 1 and resin extraction; these two extractant solutions showed also the closest correlation (r = 0,96). The rate 200 mg kg-1 of Yoorin MC and Yoorin semi finished produced the highest dry matter yield. The highest index of agronomic efficiency, however, was achieved with Yoorin semi finished.
Keywords : thermophosphate; resin; rice; Oryza sativa; Phosphorus; distrophic red-yellow latostd; soil; extractors.