Improvements in plant nutrition and fertilisation are central to any transition to a more sustainable agriculture. In addition to ways of improving nutrient use efficiency, a key area to investigate further is the transition from relying primarily on inorganic fertilisers to a greater use of organic sources of nutrition. Optimising bio-based fertilisation for a more sustainable agriculture provides a comprehensive overview of the recent research undertaken in this area, focussing primarily on the role of differing types of soil amendments and their contribution to improvements in soil organic matter content, nutrient availability, crop growth and yields. The book also reviews recent advances in biostimulants, such as plant growth-promoting rhizobacteria, and considers optimising their use to promote crop health and nutrient use efficiency.