Richard's research has led to mechanistic and conceptual advances in the area of plant-soil interactions, with a particular focus on understanding impacts of plants on soil microbial communities and feedback consequences for plant growth and ecosystem processes, especially carbon and nitrogen cycling. His research takes him to many parts of the world and is mostly focussed on grasslands. Richard has published over 350 scientific papers, inlcuding many highly cited works in leading journals such as Nature and Science, and has been repeatedly recognised as a Highly Cited Researcher in the field of ecology and environment since 2009. He has also authored and co-authored several books, including the award winning Biology of Soil (2005), Aboveground-Belowground Interactions (2010), and his recent book Earth Matters: How Soil Underpins Civilization (2016), all published by Oxford University Press.

Richard has a long-standing commitment to promoting awarness of soil biodiversuty research. To this end, he was a founder member of the Global Soil Biodiversity Initiative (GSBI), established in 2011 to create a global platform for the translation of expert knowledge on soil biodiversity into policy, and he contributed to the UN's Intergovernmental Technical Panel on Soils report The Status of the World's Soil Resources (2015) and the UK Governments Soil Health Enquiry (2016) and Climate Change Risk Assessment (2017). He was also a coordinating lead author of the UK's National Ecosystem Assessment (2011).