02718naa a2200301 a 450000100080000000500110000800800410001910000190006024501210007926000090020050001450020952017720035465000110212665000150213765000150215265000190216765000130218665000100219965000120220965000140222165000120223565000130224765000210226065000090228170000210229070000210231177300840233211050202021-04-23       1983    bl uuuu     u00u1 u    #d1 aMACHADO, M. O.  aCalcário e fontes e doses de fósforobinfluência no rendimento da soja e na química do solo Pelotas (Alfissolo).  c1983  aTítulo em inglês: Lime and rates and sources of phosphorus as influencing soybean yield and chemical properties of Pelotas soil (Alfisol).  aRESUMO - Foi avaliado o efeito de calcário e de cinco adubos fosfatados, aplicados em duas doses cada um (100 e 200 kg/ha de P2O5 total), num experimento conduzido com soja (cv. Bragg) em campo nativo localizado na UEPAE de Pelotas, durante as safras de 1973/1974, 1974/75, 1975/76 e 1976/77. O pH e o teor de Ca+ Mg trocáveis do solo aumentaram com a aplicação do fosfato-de-gafsa e, principalmente, do calcário, da escória-de-thomas e de termofosfato-de-yoorin. O Al trocável foi eliminado pela calagem e, na ausência desta, diminuiu anualmente com o emprego do fosfato-de-gafsa, da escória-de-thomas e o termofosfato-de-yoorin tiveram o melhor desempenho, podendo dispensar a calagem. No entanto, com a calagem, todas as fontes apresentaram eficiência semelhante, exceto o fosfato-de-gafsa no primeiro ano. ABSTRACT - The effect of five phosphates as sources of phosphorus for soybean (Bragg cultivar) was evaluated in two rates (100 and 200 kg/ha of total P205 ), on limed and unlimed soil conditions. The experiment was carried out under field conditions, during the soybean growing season of 1973/74, 1974/75. 1975/76 and 1976/77, at UEPAE Pelotas station. The pH and the exchangeable Ca + Mg content from the soil were increased with Gafsa phosphate, but mainly with lime, Thomas slag and Yoorin thermophosphate application. The exchangeabte Al content was eliminated by lime application and decreased annually by application of Gafsa phosphate, Thomas slag and Yoorin thermophosphate, when the lime was not applied. Thomas slag and Yoorin thermophosphate were the best phosphates for grain yield and do without lime: however, under limed soil conditions all phosphates had some efficiency, except for the Gafsa phosphate in the first growing season.  aLiming  aPhosphates  aPhosphorus  aSoil chemistry  aSoybeans  aAdubo  aCalagem  aCalcário  aFosfato  aFósforo  aQuímica do Solo  aSoja1 aVIANNA, A. C. T.1 aCASALINHO, H. D.  tPesquisa Agropecuária Brasileira, Brasíliagv.18, n.7, p. 721-727, jul. 1983.