<b>Metodologias e eficiência de extratores para zinco, cobre, ferro e manganês</b> - DOI: 10.4025/actasciagron.v31i3.736

Assessment of micronutrient extractants from soils of Paraná, Brazil

“…These results confirmed Silva et al (2009), who reported highest Cu contents in PR soils by Mehlich-1 and lowest contents by DTPA. However, Borges & Coutinho (2004) verified that DTPA extracted more Cu than Mehlich-1 and Mehlich-3, regardless of liming.…”

“…A higher Zn content by acid than by chelating extractants was also verified by Abreu & Raij (1996), Pereira et al (2001), Borges & Coutinho (2004), Araújo & Nascimento (2005), Ortiz et al (2007) and Silva et al (2009), the latter two studies focused on soils from the state of Paraná. The greater capacity of the acid agents to extract soil Zn may be attributed to solubilization of Zn forms in the soil, a fact that does not occur with DTPA since it extracts only the most soluble compounds in buffered pH (Motta et al, 2007).…”

“…These results indicate that the acid extractants (HCl and Mehlich-1) and chelating acid were equivalent in assessing Zn availability in PR soils for wheat and bean. In a study of 18 soils from the state of Paraná, Silva et al (2009) also reported the similarity of Mehlich-1, Mehlich-3 and DTPA in estimating the plant available soil content of Zn.…”

“…However, Cruz & Ferreira (1990) utilized acid extractants, salts and chelating agents for soils from Jaboticabal (SP) and concluded that all but 0.5 mol L -1 CaCl2 had significant and similar correlation coefficients between the Cu content extracted from the soil and that accumulated by maize. Likewise, Borkert et al (2004) and Silva et al (2009) detected no difference between the Mehlich-3 and Mehlich-1 extractants to assess Cu availability for soybean and for maize, respectively, concluding that both extractants may be used. Due to operational ease in the laboratory, Mehlich-1 would be more indicated since this method also allows P and K determination.…”

Ways of applying zinc to maize plants growing in Oxisol: effects on the soil, on plant nutrition and on yield

“…Other authors have mentioned that in general DTPA solution is better in relation to acid solutions in the evaluation availability of Zn in soils that have or not received the application of this element (Abreu and Raij, 1996). DTPA solution can be similar to the acid solutions due to the existence of a good correlation to the Zn content in the soil between the Mehlich-1 and DTPA methodology (Silva et al, 2009). In this way, Gonçalves Jr. et al (2006) have observed that the complexant extractors, as DTPA, extract less Zn from the soil, having greater effectiveness in the acid soil.…”