Phosphorus use in soybean in integrated production system under anticipation of phosphate fertilization

Resumo

Conservation agriculture practices, such as integrated crop-livestock system (ICLS), can result in efficiency of
phosphorus use and, economic and environmental benefits. The higher nutrient cycling, deposited crop and animal residues in
the soil surface can promote the maintenance of soil fertility. Thus, the anticipated of phosphate fertilization may be a viable
strategy of fertilization for soybean crop, in this system. The objective of this work was to determine the yield, accumulation
of P and phosphorus use efficiency (PUE) on the dry biomass and grains of the soybean crop, in an integrated crop-livestock
system (ICLS) due to anticipated fertilization of sources and doses phosphates annually applied in the soil surface. The
experiment was conducted over a period of five years, in Castro-PR, under a Typic Dystrudept, using a randomized block
design, in an incomplete factorial scheme (3×3+1), with four replications. The treatments consisted of three doses (60, 120 and
180 kg ha-1 of total P2O5
) plus absolute control, and three sources (triple superphosphate, rock phosphate – Arad and magnesium
thermophosphate) of P. The different sources no influenced and there were no interactions between P sources and doses for
the attributes: grain yield (GY), shoot dry mass (SDM), weight of thousand seeds (WTS), P accumulation in soybean (PAS),
P concentration in soybean grains (PCSG), PUE and P in residual dry mass (PRDM). Linear increases were observed in GY,
SDM, WTS, PCSG and PRDM and quadratic increases in PAS and PUE.