Response of Stargrass to K fertilization as affected by liming, N and K sources

Abstract

The effect of liming and sources of K and N on the response of Stargrass to potassium fertilization was studied on a Typic Tropohumults. Stargrass responded with up to 1,500 kg/ha of K with or without liming, when (NH₄)₂SO₄ was the source of N, but responded only to 500 kg of K/ha when urea was the source of N. Liming increased the response of Stargrass to K Fertilization when (NH₄)₂SO₄ was the source of N, but only at the highest rate when urea was used. The source of K had no significant effect on yields of Stargrass. More K accumulated in the soil but percentage recovery of applied K decreased as the rate of application increased. More K accumulated in the soil when KCI was the source of K. Marked changes in soil acidity factors occurred as a result of heavy fertilization with (NH₄)₂SO₄.