Formulation of humic substances coated fertilizer and its use to enhance K fertilizer use efficiency for tomato under greenhouse conditions

AbstractA greenhouse experiment was conducted at Land Resources Research Institute, NARC, Islamabad to examine the impact of humic substances (HSs) coating on potassium fertilizers use efficiency. Tomato variety “Rio Grande” was used. The treatments applied were T1= Control (N, P at 250 and100 mg kg−1 respectively), T2 = N, P + K at 200 mg kg−1 as SOP, T3 = N, P + K at 200 mg kg−1 as NPK blend, T4 = N, P + K at 200 mg kg−1 HSs coated SOP) and T5 = N, P + K at 200 mg kg−1 HSs coated NPK blend. Results indicated a positive impact of sole and HSs coated products on agronomic traits, nutrient concentration, fruit quality traits, flower number, fruit umber, fruit weight, chlorophyll contents, fresh and dry biomass, tissue water contents, diameter and fruit mineral composition. The response of afore said traits to applied treatment varied.