Root traits for improving nitrogen acquisition efficiency

Agriculture is the mainstay of most developing countries' economies across the globe and continues to play a vital role in the sustenance of human society. Nitrogen (N) often limits crop production and fertilizer usage is limited in developing nations, while in high-input systems intensive fertilization incurs substantial economic and environmental costs. The development of nitrogen efficient crops would ameliorate these problems. In low-input systems they will increase productivity, permitting farmers to climb out of the poverty trap of low inputs and low yields. In high-input systems they will reduce environmental pollution and crop input costs. The global significance of these issues means that the development of crops with reduced N requirement has become a high priority. There is substantial genetic variation for root traits that have potential utility for enhancing N acquisition. In this chapter, we focus on the potential benefits of root phenes that could enhance N acquisition and therefore could be deployed to improve agricultural sustainability.