How can furthering the practices of the 4R nutrient management, transform not only agricultural productivity but also contribute significantly to environmental sustainability and climate change mitigation?  Dr. Tom Bruulsema, Chief Scientist at Plant Nutrition Canada, and Yara’s Director Of Agronomy, Dr. Rob Mikkelsen are back with us to talk about the advancement of the 4Rs of Nutrient Stewardship.   In addition to Dr. Bruulsema's many jobs, he is also a committee member at the Scientific Panel on Responsible Plant Nutrition or SPRPN. In a previous episode with Tom, we talked about the ambitious mandate by the Canadian government to cut fertilizer-related greenhouse emissions by 30% by the year 2030. We talked about the critical role of the  R's of nutrient stewardship (rate, source, timing, and placement) in curbing emissions and enhancing nitrogen use efficiency.  In this episode, we will explore why there's a pressing need to further the 4Rs. We'll discuss how the 4R concept has been integrated into agricultural conversations worldwide and examine its impact over the past decade in North America and globally.  We'll also address the idea proposed by Paul Fixen in an earlier podcast about adding more "R's" to the existing framework.