Presented at the Conference of the Canadian Society of Soil Science in Edmonton, AB on 24 May 2022.
https://plantnutrition.ca/wp-content/uploads/2022/06/BruulsemaFurthering4R_CSSS2022.pdf
Society demands a lot from future farming systems. To sustainably support human life, they need to intensify production, improve human nutrition, protect and enhance biodiversity, shrink environmental and carbon footprints, and make nutrient flows more circular. Canadian agriculture is pressed to demonstrate sustainability, with particular emphasis on its carbon footprint, as governments and industry seek to meet commitments to reduce greenhouse gas emissions.
The New Paradigm for Responsible Plant Nutrition provides perspective to integrate 4R Nutrient Stewardship into changing farming objectives that support a wider range of sustainability outcomes. Priorities among the outcomes vary among countries, but in Canada as elsewhere, opportunities exist to increase use of data-driven digital solutions to support decisions, and to accelerate innovation using on-farm adaptive management. Choices among nutrient sources need to include more circular and climate-smart attributes, and rate, time, and place of application need to become more precise and dynamic.
The Scientific Panel on Responsible Plant Nutrition has suggested several new principles that can be applied to the 4Rs of nutrient stewardship. For Right Source, they include supplying nutrients in quantifiable and available forms, using climate-smart forms, using more recycled forms, and considering biological inoculants. Right Rate needs to address variability in crop response, both year-to-year and within and among fields. Right Time needs to address dynamics of changing nutrient need through the growing season. Right Place needs to avoid nutrient losses, particularly the small ones that generate large impacts.
The accountability for performance requires tracking of 4R practices, measurement of farm-level economic outcomes, and assessment of environmental and social benefits. Better ways to monitor adoption and key outcomes are urgently needed, including science-based targets and more profound application of digital technologies. This somehow has to be accomplished amidst a social climate increasingly protective of privacy and averse to mandatory compliance. The fertilizer industry has been collaborating with the agri-food sector to develop a National Index for Agri-Food Sustainability that includes holistic 4R practices and performance metrics. This presentation will outline opportunities and challenges to furthering 4R for future farming systems, and discuss the crop nutrition industry’s needs for science support and accelerated innovation.