Sugarcane crop (Saccharum spp.) has a great
importance in Brazil's economy, mainly due to sugar and
ethanol production, for either domestic consumption or
exportation, which generates a considerable income for the
country. Moreover, sugarcane can be used as alternative
forage for ruminant feeding in periods of drought.
Considering the high biomass production and low
consumption of nitrogen fertilizer, which means low
energy balance based on the ratio between the total energy
contained in the biofuel and the total fossil energy needed
by its obtention, sugarcane emerges as a powerful crop for
biofuel production (Urquiaga et al., 2005). Currently, there
is a strong trend for expansion of sugarcane area,
motivated by the increasing interest in obtaining
alternative sources of energy that can help reduce the high
CO2 emissions, characteristic of the traditional fossil
energy source. Sugarcane ethanol is considered to be an
alternative fuel for gasoline (Urquiaga et al., 2005).
Phosphorus (P) is considered the second most
essential macronutrient following nitrogen, so it may limit
plant growth, as it plays an important role in growth of
structure, its function, and transfer of energy. Agricultural
soils contain large reserves of phosphorus due to its
regular application. A large proportion of inorganic
phosphorus in soluble form is rapidly fixed to its insoluble
form after the application of phosphate fertilizers. In turn,
this important nutrient becomes unavailable to the plants
(Igual et al., 2001; Rodriguez and Fraga, 1999).