03460naa a2200205 a 450000100080000000500110000800800410001910000270006024501110008726000090019830000120020749000370021950001800025652025000043670000160293670000190295270000180297170000190298977302460300814667982007-07-27       2004    bl uuuu     u00u1 u    #d1 aOLIVEIRA JUNIOR, A. de  aAvailability of zinc, manganese and copper for soybean by different extraction solutions in Cerrado soils.  c2004  ap. 186.  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.  aMicronutrient availability can be evaluated by correlation studies between the content obtained by different soil solution extractors and the quantity of these nutrients accumulated in plants. In this manner we evaluated the efficiency of three solution extractors (Mehlich-1, Mehlich-3 e DTPA-TEA) in estimating the availability of zinc, manganese and copper for soybean in cerrado soils. The data were collected in soil calibration field experiments for micronutrients run at two sites in the region of Balsas, MA. In both sites the soil was classified as Red-yellow latosol (LVAd), but with different textures, sandy clay loam (27% of clay) and clay soil (55% of clay). Each experiment (Zn, Mn and Cu) was run for five years in a factorial arrangement (6 X 6), where six doses of lime were applied to reach base saturation between 30 to 80 %, and six doses of each micronutrient. The experimental design was in randomized blocks with four repetitions. To evaluate the efficiency of the micronutrient extraction solutions, the soil content of Zn, Mn, and Cu, were correlated with the contents of these micronutrients in soybean shoots. For zinc, DTPA-TEA was the solution extraction with the best correlation coefficient (r = 0.76) in the sandy clay loam, while in the clay soil the three solutions had similar correlation coefficients. For Mn, in both soils, DTPA-TEA was the extraction solution which best estimated the availability of Mn for soybean, when there were changes in soil pH. The other two methods, Mehlich-1 and Mehlich-3, had lower correlation coefficients. However, when the correlations were calculated inside each saturation level, the coefficients were similar, indicating that both methods might be used for estimating the availability of micronutrients when the range of base saturation or the pH of the soil is known. In the case of Cu, all the soil solution extractors evaluated were equally efficient in predicting the availability of this micronutrient to soybean, although Mehlich-1 and DTPA-TEA were slightly better than Mehlich-3. For all three micronutrients, correlation coefficients were higher in the sandy clay loam than in the clay soil. Indicating the higher readiness of the three extractors. DTPA-TEA appeared to be the most efficient method in predicting the availability of Zn, Mn and Cu for soybean in distinct soil pH conditions, although, the others methods were also efficient when the range of soil pH and of base saturation of the soil were known.1 aKLEPKER, D.1 aBORKERT, C. M.1 aNOVAIS, R. F.1 aALVAREZ, V. H.  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.