The objective of this study was to evaluate the effects of P rates and placement on P uptake, leaf P use efficiency (PUE), and grain yield of corn (Zea mays) grown in a Yellow Argissol soil, typical of the coastal tablelands.Rates of 0, 45, 90, 135 and 180kgha-1 of P2O5 were applied in either the rows or broadcast.The study was carried out during the rainy season, from June to September of 1998, at Umbaúba Experimental Station, at Umbaúba (SE), Brazil.Broadcast P fertilization resulted in higher leaf Pconcentration, compared to the row P fertilization.In response to this higher P uptake, broadcast-fertilized plants yielded more grains and presented a lesser requirement of P fertilizer to reach the highest productivity. PUE was affected by the P rates, but not by Pplacement. Increases of leaf P concentration in response to rates higher than 114.3kgha-1 of P2O5 did not result in increases in PUE.Root evaluation, performed only at the rate of 90kgha-1 of P2O5, showed that broadcast P fertilization resulted in higher root dry weight and in a better root distribution.
Zea mays; phosphorus fertilization; fertilization methods; phosphorus use efficiency; root distribution