Jacques Le Gouis

This book features five peer-reviewed reviews on improving nitrogen-use efficiency (NUE).The first chapter provides an overview of the recent advances in optimising NUE in crop production, focussing on broadacre cereals and oilseeds. The chapter also addresses the impact of underfertilisation and overfertilisation on crop yield, grain quality and profit.The second chapter outlines recent advances in understanding nitrogen (N) cycling in soil, as well as the main issues researchers and farmers are presented with when attempting to optimise productivity while minimising environmental impacts.The third chapter considers the ways in which molecular interventions can be used to optimise crop NUE in rice and how these interventions can contribute towards producing rice genotypes with high yields at low N-inputs.The fourth chapter reviews the principal mechanisms of N-uptake and efficient capture by crop root systems. The chapter also details the impact of abiotic stress factors on N-uptake and proliferation, such as soil structure and overall health.The final chapter reviews the role of traits related to N-uptake, N-assimilation and N-remobilisation in breeding more efficient varieties of wheat. The chapter also discusses future major research trends, such as high-throughput phenotyping.

This specially curated collection features four reviews of current and key research on improving crop nutrient use efficiency.The first chapter explores the relationship between rhizobacteria and plant roots, looking primarily at the recruitment of rhizobacteria by the plant to carry out particular functions, such as nutrient acquisition. The chapter highlights our current understanding of the molecular determinants of legume nodulation as well as challenges for improvements of biological nitrogen fixation in legumes and non-legumes.The second chapter considers the rising use of nitrogen (N) fertilizer in agriculture and its role in the shrinking contribution of soil organic N. The chapter explores the impact of the inefficient management of N (low nitrogen-use efficiency) and the consequent developments of major environmental issues, such as pollution to groundwater, oceans and the atmosphere.The third chapter addresses key issues in using N fertilizers in wheat production, such as product cost and environmental impact. The chapter summarises the development of N-efficient cultivars and their economic benefits, as well as their role in reducing the environmental impact of excessive N fertilizer inputs, whilst maintaining respectable yields.The final chapter considers the use of breeding techniques, including genetic variability, to develop more efficient wheat varieties with improved traits related to nitrogen capture, nitrogen assimilation and nitrogen remobilization.