YIELD RESPONSE OF BARLEY AND RAPESEED TO K-FERTILIZER INFLUENCE OF SOIL TEST K-LEVEL AND METHOD OF PLACEMENT

Field experiments were conducted in central Alberta to determine the y ield response of barley and rapeseed to KCl on soils varying in soil t est K levels and to evaluate three methods of K placement for effectiv eness. The soil test K extractant was 1M ammonium acetate solution. Pl acement methods were incorporation, banding with the seed and banding beside the seed row. The percentage of sites that responded to K ferti lizer significantly and yield increase of barley from K fertilizer dec reased with increasing soil test K in the soil. Rapeseed responded les s often to K than barley and K placement was more critical for barley than for rapeseed. Barley yields were greatest when the K fertilizer w as banded in the seed row and least when incorporated into the soil. R apeseed yields on K-responsive sites were same when the K fertilizer w as incorporated or banded beside the seed row, but tended to be greate r when banded with the seed.