Table 1.

Some examples of the instruments and addressees, practical measures, and potential bottlenecks to achieve each 5R strategy

R strategy objectives	Instruments and addressees	Practical regional/farm measures	Potential bottlenecks
Re-align P inputs to match actual P requirements	Legislation to restrict overuse of P in agriculture [government, farmers’ organizations, feed companies]	Establish industry–farmer agreements on lowering the mineral P supplementation in animal feed and increase its digestibility	Limited knowledge on optimizing production methods with low P inputs (e.g., improving prediction of soil P supply)
	Improve tools and guidance to encourage better nutrient management [extension services, consultancy firms]	Mine soils with a high P content and improve the P status of soils with a low or insufficient P status	Farmer implementation of precision farming principles and practice
	Ban unnecessary P products and additives (e.g., detergents, food/feed additives) [government, industry]	Improve precision farming technologies to increase P efficiency in both livestock and cropping systems	Suitable and economic alternatives to non-essential P products
			Enforcement/control of any P input restrictions
Reduce P losses to water to minimize eutrophication risk	Define and facilitate a catchment-based approach to reduce P loads from point and diffuse sources with well defined targets [all catchment stakeholders]	Develop more accurate methods to quantify point and diffuse source contributions to eutrophication	More evidence to link agricultural P mitigation measures to ecological impacts
	Develop markets for the provision of ecosystem services whereby the beneficiaries pay land managers for their provision (e.g., upstream thinking) [research, consultancy firms]	Increase awareness of water quality issues from upstream rural land use and farm yards (e.g., septic tanks), and from urban areas	Poor uptake of measures due to lack of farmer engagement
		Select, implement and monitor a set of targeted measures to reduce P losses	Conflicts between stakeholders; for example between improving water quality and agricultural productivity
Recycle P in bioresources more effectively to substitute inorganic fertilizer consumption	Ease legislation to encourage wider use of society’s bioresources on farms and by industry [governments, farmers’ organizations, conservation agencies]	Integrate livestock and cropping systems at regional scale and fully exploit fertilizer substitution potential at field scale	Market prices for bioresources regulated by manure surplus rather than on agronomical value
	Establish regional agreements to facilitate more uniform distribution of livestock manure to arable farms [governments, farmers’ organizations]	Improve quality and value of recycled materials through better sourcing and treatment (e.g., manure treatment/separation)	Limited knowledge to support full field-scale substitution of various bioresources for fertilizers
		Refine feed formulations to increase manure N:P ratios and their uniform redistribution	Acceptability by society and the food industry of human waste derived products; for example in relation to food safety
Recover P in society’s wastes, by-products and residues for re-use	Increase societal dependence on a circular economy with recycling targets (e.g., tax on primary P imports, zero waste) [governments, industry]	Implement new technologies to recover P from society’s wastes	Time lag in taking promising recovery options/technologies to the market
	Subsidize investments in P recovery technology in collaboration with industry [governments, industry]	Improve P accounting methods to maximize opportunity for recovery in different parts of the food chain	Current technologies too uneconomic for adoption and/or reluctance to reflect the real price of primary P production by including externalities
	New business models and financing mechanisms to foster innovations to the market [industry, consultancy firms]	Minimize waste production to limit the need to recover P	Backlash on business models if subsidies are removed
Re-design P use in society with a focus on food systems	Mainstream sustainable P use into European and national legislation [governments, consumer organizations]	Increase public awareness of how dietary choice influences P demands and possible health risks of high P diets (the health and sustainability challenge)	Limited knowledge to confirm links between high blood serum P and increased human health risks
	Specify P dietary requirements and prioritize essential demands [industry, research, consumer organizations]	Lower the P contents of foods by reducing their P requirements through plant breeding and food processing	Reluctance of the public to change food habits; e.g., the focus is now on calories and proteins but not nutrients or their sustainable use
	New urban/rural spatial planning models for circular economies [governments, urban planners, consumer organizations]	Plan urban areas to maximize P recycling opportunities	Timelag in developing foods with inherently lower P contents Integrating P sustainability into urban planning