The usefulness of Mehlich 3 and 1 M HCl extractant to assess copper deficiency in soil for environmental monitoring purpose / Przydatność ekstrahentów Mehlich 3 i 1 M HCl do oceny niedoborów miedzi w glebie pod kątem monitoringu środowiska

The aim of this study was to compare two soil tests, 1 M HCl and Mehlich 3, to extract phytoavailable Cu forms from the soil. The evaluation of tests was performed on the basis of the correlation between soil Cu extracted by the studied extractants, and plant Cu or yield of a test plant. Data for the calculation originated from the microplot experiment with winter wheat. The experiment included three soils that differed in texture, pH level and copper content. Each of the soil was fertilized with five doses of Cu: 0, 4, 8, 12 and 16 kg • ha⁻¹ against two pH levels. The results showed a strong correlation between the two soil tests and their similar usefulness for the extraction of copper available to plants. On the basis of Pearson correlation coefficients and equation of simple regression, it was found that Mehlich 3 was slightly more useful for heavier soils with higher pH, whereas 1 M HCl was better suitable for acid sandy soil.