Epsilon Open Archive

Abstract

The use of more nutrient-efficient crops is
important for maintaining yields while enhancing
environmental sustainability. Various approaches are
being applied to evaluate aspects of plant nutrient use
efficiency, among them ecological concepts based on
accumulation and losses of biomass and nutrients,
agronomic concepts with a major focus on agricultural
crops and harvested products, and physiological
approaches assessing single physiological processes
important for nutrient use. Unfortunately, the various
approaches are often not compatible. Here we propose,
with the example of nitrogen (N) use efficiency (NUE)
of cereals, to integrate the functionally important
components of NUE in a common conceptual framework.
We link productivity to N in crops and seeds and consider the whole life-cycle of the crop (including seeds). Three major components of NUE are separated: The N uptake efficiency, grain-specific N efficiency and grain N concentration. The three components combine to a measure of overall NUE in terms of the N yield in harvested grain per unit of N in seed grain or soil N. The concept can be applied for both annual and perennial plants, which is demonstrated with the examples of winter wheat and a perennial energy crop (Salix) grown in Central Sweden.