02557naa a2200169 a 450000100080000000500110000800800410001910000180006024500620007826000090014030000120014949000370016150001800019852017470037870000160212577302460214114667752007-07-27       2004    bl uuuu     u00u1 u    #d1 aSFREDO, G. J.  aCritical levels of sulfur for soybean in brazilian soils.  c2004  ap. 118.  a(Embrapa Soja. Documentos, 228).  aEditado por Flávio Moscardi, Clara Beatriz Hoffmann-Campo, Odilon Ferreira Saraiva, Paulo Roberto Galerani, Francisco Carlos Krzyzanowski, Mercedes Concordia Carrão-Panizzi.  aModern agricultural technologies, intensive use of fertilizers, without S or with low S content, and improper soil management, lower the organic matter content in soil, changing after S availability. In 1998/99, sulfur fertilization research was conducted at several locations in Brazil: in a alic oxisol (latossolo vermelho-escuro álico) at Ponta Grossa, PR, in a eutrofic oxisol (latossolo roxo eutr+ofico) at Londrina, PR, in a dystrofic oxisol (latossolo vermelho-amarelo distrófico) at Sambaíba, MA, and in a dystrofic oxisol (latossolo vermelho-escuro distrófico) Rondonopólis, MT. The objective was to determine the effects of S on soybean yields and to establish critical levels of S in each soil. The experimental design was randomized blocks, with five S levels (0; 25; 50; 75 and 100 kg ha-1) and the sulfur source was elementary sulfur, with 98% S. In the crop year of 2000/01, in Bom Jesus (PI), in latossolo vermelho-amarelo, an experiment was conducted with five levels of S (0; 20; 40; 80; 120 kg ha-1 of S) with three source of sulfur: Simple Superphosphate; Elementary sulfur and Gypsum. From the results, the critical level of S in each soil were determined extract with Ca(H2PO4)2 0,01 M/L and determined using Turbidimetric methods, was: in Londrina and Ponta Grossa the limits were: low &lt5 mg dm-3; medium 5-10 mg dm-3 and high &gt 10 mg dm-3 for soil depth at 0-20 cm; and low &lt20 mg dm-3; medium 20-35 mg dm-3; and high &gt 35 mg dm-3 for soil depth at 20 to 40 cm. In Sambaíba, Bom Jesus and Rondonópolis soils, the critical levels were: low &lt2 mg dm-3; medium 2-3 mg dm-3; and high&gt 3 mg dm-3 for depth at 0-20 cm and low &lt6 mg dm-3; medium 6-9 mg dm-3; and high &gt 9 mg dm-3 for depth at 20-40 cm.1 aKLEPKER, D.  tIn: WORLD SOYBEAN RESEARCH CONFERENCE, 7.; INTERNATIONAL SOYBEAN PROCESSING AND UTILIZATION CONFERENCE, 4.; CONGRESSO BRASILEIRO DE SOJA, 3., 2004, Foz do Iguassu. Abstracts of contributed papers and posters. Londrina: Embrapa Soybean, 2004.