Response of rice to soil and foliar application of K2SO4 fertilizer

A field experiment was conducted at village Jatri Kohna, district Sheikhupura during the growing season of 2003 to compare foliar application of K2SO4 at various concentrations (0.5, 1.0, 2.0, 4.0 and 6.0 %) with soil application of K2SO4 at the rate of 50 kg K2O per ha on yield of rice crop. The experiment was arranged in a Randomized Complete Block Design with three replications. Number of fertile tillers, straw and paddy yields of fine grain rice (Basmati-385) were recorded. Foliar application of K2SO4 at different concentrations significantly influenced the yield components. Among all the foliar application treatments, foliar application with 6.0% K2SO4 significantly out yielded than rest of the treatments that was statistically at par with soil application of K2SO4 @ 50 kg K2O per ha. Maximum paddy yield (3837 kg per ha) was obtained with this treatment. Paddy yield in different treatments followed the order: 50 kg per ha K2O soil application = 6.0% greater than 4.0% greater than 2.0% greater than 1.0% greater than 0.5% K2SO4 greater than control. Plant samples analyzed for K concentration showed significant increase in K uptake by rice paddy and straw with foliar application of different K2SO4 concentrations. Interestingly, foliar application at 6.0 % K2SO4 (24.12 kg per ha K uptake) showed statistically equal performance as that of K2SO4 soil application at the rate of 50 kg K2O per ha (24.70 kg per ha K uptake). However, in case of K uptake by straw, foliar application of K2SO4 at 2.0, 4.0 and 6.0 % concentration showed similar results but was statistically comparable to soil application of K2O @ 50 kg per ha. Our results suggested that foliar application of K2SO4 at 6.0 % concentration was safe and appropriate and could produce yield of rice equal to the yield obtained with soil application of K2O at the rate of 50 kg per ha.