Irrigated Potato (Solanum Tuberosum L.) Yield, Quality Response and Nitrogen Losses as Influenced by Nitrogen Fertilizer Management and Cultivars

• Main Author: Ghosh, Upasana
• Format: Others
• Published: North Dakota State University 2017
• Online Access: https://hdl.handle.net/10365/26492

Field studies were conducted in 2015 and 2016 growing season at Northern Plains Potato Growers’ Association Irrigation site near Inkster, ND to evaluate the effectiveness of enhanced efficiency fertilizers (EEFs) in maintaining yield, quality and reducing environmental nitrogen (N) losses in irrigated potatoes (Solanum tuberosum). Two types of EEFs i.e. SuperU (urea with urease and nitrification inhibitor) and ESN (polymer coated urea); grower’s standard fertilization and unamended urea were applied in three late-sown russet potato cultivars. Our findings suggested that yield responses vary widely with respect to years, length of growing season and cultivar type. Among EEFs, ESN consistently maintained yield compared to conventional fertilization practices. In shorter growing season (114 days), no yield benefit over N rate of 225 kg ha-1 was obtained with higher N rates (280 kg N ha-1) and different N sources in all three cultivars. Determinate cultivars can be a better choice to get good yield with lower N rate in shorter growing seasons. Both of the EEFs significantly reduced N losses through ammonia (NH3) volatilization and nitrous oxide (N2O) emission compared to unamended urea and grower’s standard fertilization practice. SuperU did not reduce residual soil nitrate (NO3-) compared to unamended urea while ESN reduced residual soil NO3-. Overall, ESN or polymer coated urea (PCU) is a promising choice for reducing N losses from irrigated potatoes. Plant N status assessment is important for yield prediction. Despite of being time consuming, total N concentration in petioles gave the better estimate of crop N status compared to standard petiole NO3-N concentrations. For early season quick N status measurement, ground based active optical sensors should be used in a cultivar specific way. Nitrogen fertilization recommendation for irrigated potatoes in North Dakota should be recalibrated considering length of growing season and cultivar type. === North Dakota (USDA) Specialty Crop Block Grant Program