A soybean trial using a sample of Dark-Red distrophic medium texture Latosol was carried out under greenhouse conditions at the Escola Superior de Agricultura ‘Luiz de Queiroz’ in Piracicaba, São Paulo, Brazil, from December 1993 to July 1994, to evalvate the effects of subsurface compaction and the application of gypsum on nitrogen and phosphorus levels of soybean shoots. A scheme in a bloc randonized desdign, with treatments arranged in a 4 x 4 factorial, with four replications, corresponding to the soil surface […]

Six calcareous soil profiles (P1, P2, P3, P4, P5 and P6) were investigated with regard to their main characteristics of soil organic matter related to structural organization. The effect of degrading processes on these soils was also considered, mainly under intensive cultivation. Based on morphological in situ observation and analytical data, the profiles P1 e P2 showed organic matter with an advanced level of evolution presenting reasonable amounts of low polymerized materials (fulvic acids). Conversely, profiles P3, P4, P5 e […]