Nitrogen Use Efficiency Analysis

Nitrogen use efficiency (NUE) analysis is the set of agronomic indicators used to quantify how effectively applied nitrogen is converted into harvested yield and nutrient uptake, and how much escapes to the environment. Synthesized authoritatively by Jagdish Ladha and colleagues in 2005, the family includes agronomic efficiency (extra yield per unit of nitrogen applied), recovery efficiency (the fraction of applied nitrogen the crop takes up), physiological efficiency (yield produced per unit of nitrogen taken up), partial factor productivity (total yield per unit of nitrogen applied), and the partial nutrient balance of nitrogen out in harvest versus nitrogen in from inputs. Because nitrogen is the most yield-limiting and environmentally costly nutrient in cereal systems, these indicators are central to diagnosing fertilizer performance, guiding the right rate, source, timing, and placement, and benchmarking the sustainability of cropping systems.