Paper from 2010 AAB conference:

Kindred, D. and Sylvester-Bradley, R. (2010). Routes to reducing the N requirements of high yielding wheat crops. Aspects of Applied Biology 105 Water and Nitrogen Use Efficiency in plants and crops, 97-106

Summary:

Improving the efficiency of nitrogen (N) use to meet the aims of growers, end-users and society requires that grain yields are maintained or increased whilst N requirements of crops are reduced. The N use efficiency (NUE) concept does not adequately capture these aims. We therefore adopt the term HYLO – High Yield, Low N Optima. Reducing grain protein content of varieties seems one of the most promising routes to reducing N requirements of feed wheat. However, improvements in recovery of N from soil and fertiliser, as well as improvements to N harvest index, are the only routes currently available for bread wheats. Development and commercialisation of HYLO varieties will depend crucially on there being appropriate measures in variety testing systems to distinguish low N requirements.