Działanie potasu na glebach wyczerpanych z tego składnika

On acid (NP) soil or on this soil limed (CaNP) very poor in available potassium increased doses of potassium fertilizer (0; 0.3; 0.6 and 0.9 g K per pot of 6.5 kg of soil) were applied. During 4 years (1991-1994) the maize and during 2 years (1992-1993) triticale was grown. On limed soil marked increase of the yields of maize after K application was noted. On acid soil higher doses of K-fertilizer decreased the yields of maize and triticale. In consequence on very acid soil the ratio of K:(Ca+Mg) in maize was higher than 2.5:1, what is considered as harmful for ruminants. On soil where the lime was applied, the utilization of potassium from fertilizer was much higher than on very acid soil.