[en] In this experiment, we investigated the effect of microwave oven‐drying on soil samples for chemical tests. Samples were irradiated until they achieved a constant weight and for one‐half the time required. Two other treatments were applied, air‐drying at room temperature and forced air oven‐drying at 60°C. Samples were analyzed for water pH, 0.01M CaCl2 pH, organic carbon (C), Mehlich 1 and resin available phosphorus (P), exchangeable potassium (K) and calcium (Ca) plus magnesium (Mg), and potential acidity [1N calcium acetate (pH 7.0) extractable hydrogen (H) plus aluminum (Al)]. The results showed that microwave‐drying can induce erroneous interpretations of the “fertility status”; of the soil, thereby affecting fertilizer recommendations and lime requirement determinations. (author)