Działanie nawożenia magnezem na rośliny i gleby. Część II. Działanie magnezu w zależności od właściwości fizykochemicznych gleb

During 3 years (1991-1993) on 3 soils the pot experiments with red clover and Italian ryegrass were conducted. Increased doses of magnesium (0; 0.2; 0.4 and 0.6 g Mg per pot with 6.5kg of the soil) were applied. The soils were differentiated in the content of humus (0.90—4.90%), particles <0.02 mm (13-27%), and exchangeable magnesium (2.6-9.5 mg) and calcium (17-212 mg per 100 g of the soil). On the soil with the smallest content of soil particles <0.02 mm, humus, and exchangeable Mg and Ca and the increase of yields under Mg treatment were the highest. The highest yields were also on soil with the largest amount of exchangeable Mg, but middle a of humus and soil particles <0.02 mm. Even by very different rates of magnesium fertilizer, sum of cations K + Mg + Ca, and the ratio of K:(Ca+Mg) in plants were similar. This ratio in red clover was more narrow (0.71) than in Italian ryegrass (1.69).