Badania nad molibdenem w systemie gleba-roslina

Paper discussed the needs of molybdenum fertilization in Poland and the methods of evaluating soil abundance in this micronutrient. It was stated rather low diagnostic usefulness of determining Mo extractable by Tamm's solution acc. to Grigg's method, so called Mo-number as well as the Mo extraction in 1 mol · HCI dm⁻³ solution. Such diagnosis requires an additional considering of different soil traits, such as pH, extractable P and Fe content, granulometric composition, kind of crop etc. Authors described the achievements of the Sims' school from Lexington, USA, which proved the buffering with ammonium oxalate to pH 3.3 to be an im proper step. Good correlation among Mo content in soil, applied Mo rates and Mo uptake by the plants, was obtained at using the oxalate solution of pH 6.0, or the ion exchangeable resins in particular. Mentioned pH 6.0 was close to pH of Kentucky soils as well as to pH of the plant sap of most crops. Discussed problems need to be studied under Polish conditions.