Using robust, pairwise comparisons and a global dataset, we show that nitrogen concentration per unit leaf mass for nitrogen-fixing plants (N2FP; mainly legumes plus some actinorhizal species) in nonagricultural ecosystems is universally greater (43-100%) than that for other plants (OP). This difference is maintained across Koppen climate zones and growth forms and strongest in the wet tropics ...

In this review, we present the recent developments and future prospects of improving nitrogen use efficiency (NUE) in crops using various complementary approaches. These include conventional breeding and molecular genetics, in addition to alternative farming techniques based on no-till continuous cover cropping cultures and/or organic nitrogen (N) nutrition. Whatever the mode of N fertilization...

Nitrogen (N) is an essential and often limiting nutrient to plant growth. Maize grain yields are highly responsive to supplemental N, leading to annual application of an estimated 10 million metric tons of N fertilizer to the maize crop worldwide (FAO 2004). Nearly all cultivated maize in developed countries receives some form of N fertilizer and N use is increasing in developing countries, whe...

Since nitrogen (N) is the most essential nutrient for plants and a major limiting factor in plant productivity, doubling agricultural food production worldwide over the past four decades is associated with a 20-fold increase in N fertilizer use. As a consequence, use of N fertilizers in agriculture has already shown a number of detrimental environmental impacts. Therefore, the need to reduce N ...

Introduction At a global scale, human activity has increased the flux of N two-fold (Vitousek et al. 1997), particularly driven by large scale fertiliser manufacturing (Fowler et al. 2013). Additionally, the ability to transport inputs and outputs cheaply and extensively has led to substantial growth in agricultural production over the past 50 years with an accompanying 40% increase in world po...