Wheat yield response to potassium sulfate supplemental doses in Urban agriculture of kabul, afghanistan

Wheat, strategic crop of Afghanistan is cultivated in irrigated and non-irrigated land surfaces. Insufficient rainfalls trigger the intensification of wheat cultivation in irrigated areas. Indiscriminate use of irrigated land depletes crop essential nutrients which lead to soil potassium (K+) mining. A research has been conducted (2012 – 2013) to evaluate the supplemental effect of three levels (25; 35 and 45 kg ha-1) of potassium sulfate (PS, K2SO4) with a basal dose of 250 kg urea ha-1 and 125 kg diammonium phosphate (DAP) ha-1, on wheat yield in Urban Agriculture (UA) of Kabul. The wheat (winter var.Gul 96) was cultivated in two seasons. Randomized complete block design (RCBD) was used. Four treatments were replicated four times and were irrigated upon the requirement. The parameters; plant height; number of productive tiller/plant; number of spikelet/spike, Spike length, thousand grain weight, and total grain yield were measured. The results showed that wheat var. Gul 96 is a facultative variety. The plant heights in 25, 35 and 45 kg PS ha-1 were greater (25.60, 25.12 and 24.90%) than control (24.38%), respectively. Plant heights in fall cultivation (FC) were higher (54%) than spring cultivation (SP, 46%). Numbers of productive tillers per plant were greater (26.44%) in both seasons in 25 kg PS ha-1 than control (26.27%), whilst, in 35 and 45 kg PS ha-1 were (23.03 and 24.26%), less than control, respectively. Numbers of spikelet per spike was higher in 25 and 45 kg PS ha-1 (25.26%) than control (24.97%), whereas, plot of 35 kg PS ha-1 had less (24.52%) than control. Thousand grain weights were greater in 25, 35, and 45 kg PS ha-1 in both seasons by 25.40, 25.16 and 24.98 % than control (24.52%), respectively. Total grain yield in both seasons in 25 and 45 kg PS ha-1, were greater (27.89 and 26.40%) than control (23.86%), respectively, while, plot of 35 kg PS ha-1 had less (21.86%) than control. Statistically the differences were highly significant (P< 0.05).