Nitrogen Agronomic Efficiency and Estimated Losses in Potato with Enhanced-Efficiency Fertilizers

The objectives were to i) assess the effect of enhanced-efficiency nitrogen (N) fertilizers (EENF) [maleic itaconic acid copolymer (NSN) or 3,4-dimethylpyrazole phosphate (DMPP)] and urea on potato (Solanum tuberosum L.) tuber yield, N agronomic efficiency (NAE), recovery in (NREtuber) plant (NREplant), physiological efficiency, residual inorganic soil at harvest (Nresidual) losses (Nlosses) ii) determine impact amount drainage water NAE Nlosses. On-farm experiments conducted seven sites with two (EENF urea) rates (0 100 kg ha−1). A mass balance was used calculate At (one NSN one DMPP), yield response greater EENF than (avg. 5.0 Mg NAE, NREtuber NREplant 17%, 31% 25% higher urea, respectively. These efficiencies decreased as increased. estimated Nlosses 12% lower EENF, being reduction particularly relevant increasing water. Therefore, using combination irrigation management that ensures low amounts is essential for maximizing fertilizer use minimizing production systems.