Long-term phosphate fertilization, mycorrhizal inoculation and historical land use influence on soybean growth and P uptake

ABSTRACT Phosphorus is a key-nutrient in the fertility management of highly weathered tropical soils. So, this work was carried out with the objective of evaluating the influence of the interaction between P doses, mycorrhizal inoculation and historical land use on soybean growth and P uptake in five Latosols (Oxisols) with contrasting chemical, physical and mineralogical properties under a continuous long-term phosphate fertilization (more than 15 years). The plants were cultivated in 4.5L-plastic pots containing 4 kg of soil in a completely randomized design, four replications and 2x2x2 factorial scheme with two P doses; and with or without mycorrhizal inoculation; and soils cultivated for long periods and non-cultivated (under native vegetation). There were two cultivations of ten weeks each. Shoot dry mass, P content and accumulation in the shoot dry mass were evaluated after each cultivation period. The cultivation history reduced the response to P application and inoculation. The soybean response to inoculation was greater in cultivated soils and when the lower P dose was applied. The soybean response magnitude to these variables was different among the studied Latosols. The mineralogical and chemical attributes of the Latosols were determinants.