Effect of potassium application on wheat ( Triticum aestivum L.) in old Himalayan Piedmont Plain

A field trial was conducted in Rabi season 2001-2002 at the Bangladesh Agricultural Research Institute’s Agricultural Research Station (BARI ARS) farm, Thakurgaon to evaluate a higher dose of K (66 kg K/ha) for maximizing yield of wheat and sustain soil native K level for wheat in north-western (NW) region of Bangladesh. To accomplish the objective, three levels of K (T 1 = K 0 , T 2 = K 66 , and T 3 = K 38 (Farmers' practice) were tested. T 1 = K 0 and T 2 = K 66 were tested under soil test based (STB) N 116 P 15 S 36 Z n1 B 1.7 fertilization and these two treatments T 1 and T 2 were compared with the farmers' own fertilization practice N 68 P 24 K 38 S 16 Zn 0 B 0 (T 3 ). Results showed that the treatment (T 2 ) i. e. K 66 with STB dose produced the better yield of wheat (var. Protiva). The highest gross return of Tk. 35,610/- and the highest net-return of Tk. 30,479/- was obtained with the treatment T 2 (STB). The dose of 66 kg K/ha for wheat growing in Old Himalayan Piedmont Plain (AEZ-1) was not adequate, and thus needs to be increased to maintain the soil K reserve, since there was an apparent negative balance of K in the soil with sole use of chemical fertilizers. The recommended P dose of 24 kg P/ha in wheat season created a positive balance of P. The STB dose for S and Zn @36 and 1 kg/ha, respectively, in wheat season created a positive balance of S and Zn in soil. Keywords: Potassium; fertilizer management; wheat; nutrient balance sheet. DOI: 10.3329/bjar.v35i2.5883 Bangladesh J. Agril. Res. 35(2) : 207-216, June 2010