EFFECTS OF RATE, SOURCE AND METHOD OF APPLICATION OF N, P AND K ON GROWTH, NUTRIENT UPTAKE AND YIELD OF BARLEY

Abstract

Barley was grown for 2 yr on Charlottetown fine sandy loam with various methods of application of fertilizers made from two nutrient source combinations. Grain yields were generally higher when fertilizer was placed 5 cm to the side of, and 5 cm below, the seed than when fertilizer was broadcast or drilled with the seed. Yields were higher with drilled than with broadcast fertilizer, except when urea and diammonium phosphate were used as N and P sources. High yields were obtained when P was drilled with the seed and N and K broadcast. Throughout the growing season, the uptake of P was lower from broadcast than from drilled or placed fertilizer. Low yields with broadcast fertilizer were attributed to the low availability of P. When N was broadcast and P drilled, yields were similar for broadcast and drilled K, although the uptake of K was lower when K was broadcast. Yield reduction where fertilizers containing urea and diammonium phosphate were drilled with the seed was attributed to damage from ammonia released by urea and diammonium phosphate.