Potato tuber yield and quality in response to different nitrogen fertilizer application rates under two split doses in an irrigated sandy loam soil

Management strategies to minimize nitrogen (N) losses to the atmosphere and water bodies from potato production fields while maintaining tuber yields and quality relies on good N management. A 2-year (2016-17 and 2017-18) field trial with 'Symphonia' potato was completed on a sandy loam soil irrigated with flood irrigation in Punjab, Pakistan to investigate the effect of N fertilizer rate on vegetative, yield and tuber quality parameters. The N fertilizer treatments comprising six N rates from 0 to 300 kg ha(-1) were applied at 50 kg N increments. Number of stems and tubers plant(-1) showed a quadratic response while other parameters revealed cubic trends in response to N fertilizer rates. Applying more than 250 kg ha(-1) of N fertilizer did not increase vegetative growth and yield. In conclusion, the optimal N-application rate of 250 Kg ha(-1) has great potential to improve yield and quality of potato in the sub-tropical region of Punjab, Pakistan. These findings, besides improving productivity can minimize the risk of N fertilizer loss to the atmosphere.