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The Sustainable Phosphorus Alliance (North America) second stakeholder Forum, Washington DC, looked at phosphorus management today and tomorrow.

Nearly one hundred researchers, administrations and companies from the USA and Canada met in Washington DC, May 19th 2017, at the second stakeholder meeting of the Sustainable Phosphorus Alliance. The first meeting took place in 2015 (NAPPS, see SCOPE Newsletter 100). The meeting discussed the conclusions of the NSF P-RCN (National Science Foundation Phosphorus Research Coordination Network, see this Newsletter) and the Newtrient US dairy’s innovative industry initiative on manure phosphorus management technologies.

The Forum was the launch point for the North America sustainable phosphorus action platform, which has now finalised its structure and mode of action under the name “Sustainable Phosphorus Alliance” after several years establishment phase under the name NAPPS. The Alliance today already has as members: OCP, FEECO International, NACWA, Ostara, Renewable Nutrients, WE&RF, Consultants Allied, Brookside, The Sustainability Consortium, with others underway.

The Alliance’s near future activities will include a working group on phosphorus recycling from sewage biosolids and manures, and a webinar on nutrient emissions trading (date to be announced soon at and - Events).

Jim Elser, Sustainable Phosphorus Alliance, opened the meeting, underlining the complexity of the phosphorus sustainability challenge, because different groups and different regions have differing objectives. In North America, the need to act on phosphorus management is clear, with a strong driver being ongoing issues with algal blooms in lakes and rivers, impacting recreation value and even in some cases water supply. At the same time, livestock producers face pressure from residents and environmental groups, including tort cases for nutrient pollution and legal cases proposing to classify manure as a “hazardous waste”.

However, we should also remember the positive news which doesn’t make the headlines: phosphate fertiliser is key to feeding the planet. Improved phosphorus management can create new business opportunities and jobs in recycling and innovative techniques, and is essential to the economic sustainability of farming.

Steve Rowe, Newtrient, emphasised the opportunities offered by nutrient recycling calling participants to “see the spaces in the forest, not the trees” (the obstacles). Newtrient (see box) is a new type of innovation company, with environmental, economic and social objectives, with an underlying goal to restore society’s confidence in farmers. Its objectives are to reduce the dairy industry’s environmental footprint whilst also making this economic, in order to produce both food and clean water.

Newtrient aims to make money from manure through innovative valorisation approaches. Farmers should have three products: milk, meat and manure. The fertiliser industry can find opportunities for new markets with local recycled fertiliser products based on manures.

To take this forward, Newtrient has developed an online ‘catalogue’ of manure treatment suppliers and technologies (see box), including identifying solutions which Newtrient’s experts consider to have potential and working with suppliers to incubate and develop promising technologies.

However, he notes that agriculture is a “price taker”, with the retail and food industries setting the price and generally not paying for environmental quality. Innovative approaches are needed to make environmental quality economically viable for farmers.

One promising approach is an environmental services or emissions reduction marketplace. This could work if established at a wide scale, and if a recognised system is established for validating and certifying farmers’ emissions reductions. Farmers can today often reduce nutrient emissions at significantly lower cost than making further reductions to point sources which are already regulated (increasing cost of removing the next kg of phosphorus). Development of credit certification criteria and a trading clearing house system are underway with the States of Vermont and Wisconsin.

Michael Weintraub, Toledo University, USA, presented the work of the P-RCN ecosystem services group, looking at phosphate use and losses to the environment. A key message is that phosphorus losses are in many cases not directly connected to inputs to agricultural systems. Large river basin examples in different parts of the world show that phosphate fertiliser use has been reduced over recent decades, but basin outflows in river water have not fallen.

This disconnect between farm phosphate inputs and surface water levels results from a range of factors, including accumulation in the twentieth century of “legacy” phosphorus stocks in both agricultural soils and in aquatic sediments, high losses during storm events or preferential pathways (such as cracks in soil which allow direct runoff to water bodies).

Over application of fertiliser in China has resulted in considerable increases in soil available phosphorus: from 7.4 to 21 mg-Olsen-P/kg soil from 1980 to 2006. On the other hand, recent studies in North China have shown that no application of phosphorus for two years did not reduce crop yield for intensive maize production, suggesting a role of soil accumulated P in sustaining maize grain production (Jianbo Shen, China Agricultural University, unpublished data).

Brooke Mayer, Marquette University, USA, summarised the P-RCN phosphorus removal and recycling group conclusions. P-RCN concludes that phosphorus recycling technologies are today available, but that they are not implemented because of economics or absence of policy drivers. The recovered phosphate product in many cases does not today cover the cost of recycling. Note: a similar conclusion was reached at the P-REX/ESPP/EU Commission workshop, Berlin, 2015, see SCOPE Newsletter 111.

However, the economics can change if phosphorus recovery is part of a “total value” proposal, for example in synergy with recovery of energy, nitrogen and other materials, or because of other ‘services’ delivered, for example improving waste water treatment performance (often the case for struvite recovery in sewage works). Other ‘services’ such as Sustainable Development Goals (food system security, equity, water quality) are today however not monetarised.

P-RCN underlines that solutions need to be adapted to specific local situations. It is necessary to identify where are significant phosphorus flows potentially available for recovery in different regions and industries and in what form is the phosphorus (concentrated or dilute, organic or inorganic, soluble or particulate) because this will define opportunities, appropriate intervention points and technologies, and costs for improving water quality or for nutrient recycling.

Economic viability may come from some kind of pollution credit system. For example, Boise city, Idaho, is building phosphorus removal system on an agricultural drain, because this is more economic than removing phosphorus to tighter discharge limits at the municipal waste water treatment plant. The drain treatment will be a near 20 ha system with sedimentation basin, constructed wetlands, aluminium chemical dosing and settling ponds. The US EPA permitting information specifies that the municipal sewage works discharge consent will be 0.25-0.35 mgP/l monthly average, with an obligation to achieve 0.07 mgP/l in the receiving stream. The drain treatment system will be obliged to remove 1.5x the phosphorus load resulting from the sewage works discharge being higher than 70 µgP/l and has a design capability to remove 28 tonnes of P per year. The total phosphorus removed from the watershed will thus be higher than by requiring the tighter limit (0.07 mgP/l) at the municipal sewage works.

Heidi Peterson, Minnesota Department of Agriculture, USA, presented P-RCN’s work on the transition process towards sustainable phosphorus management. She noted that since the mid-1970’s, Minnesota’s agricultural niche innovation and political actors have aligned, resulting in a transition toward more efficient phosphorus use. In the 1990’s, phosphorus input in mineral fertilisers was approximately equivalent to crop phosphorus offtake (efficiency near 100%; however, lower where manure phosphorus was additionally applied). Over the last decade, since the phosphorus price peak, efficiency has exceeded 100%, or in other words, farmers are “mining” legacy soil phosphorus. At this same time, advancements have been made in crop genetics and harvesting efficiency. To further improve crop phosphorus efficiency, work is needed to enhance precision agriculture technology so that real-time soil phosphorus tests (see above) for detail-scaled field zones could inform fertiliser application.

P-RCN noted that the transition to more sustainable phosphorus management will necessitate innovation, but also collaboration and integration to ensure uptake.

Dana Cordell, University of Technology Sydney, presented a phosphorus sustainability change model for North America, resulting from the discussions and input from stakeholders at the first North America Sustainable Phosphorus Alliance (NAPPS) Forum 2015. This model identifies key aspects of a desirable future phosphorus management, drivers which might push to move towards this ideal, and transition pathways / actions which might enable the necessary changes. There is general agreement that technological and social innovation is necessary for sustainable phosphorus management, and this model aims to facilitate uptake of innovation by synthesis and legitimisation across a wide range of stakeholders. Key aspects of a sustainable phosphorus future for North America, as proposed by the 2015 Forum participants, include collaboration across industry sectors and different stakeholder sectors, a circular economy for nutrients, nutrient policy governance and shared responsibility for societal costs. Public water and waste utilities and farmers are conservative, so important drivers for change will be fear of regulation and supply insecurity. Possible proposed pathways to change include: regulation, innovation, bio-economy, removing regulatory barriers, information about the time-lag between phosphate use and environmental impacts, facilitating capital investment and demand for healthy food and diet. The model developed is included below. It aims to provide a high-level blueprint for change and a discussion basis for engaging stakeholders. The proposed objective of near 100% phosphorus recycling by 2040 may not be realistic, given trade-offs with other impacts and costs, but provides a basis for scenario proposal.

Cordell P Model

Chris Thornton, European Sustainable Phosphorus Platform (ESPP), summarised developments driving phosphorus sustainability in Europe (see slides at, from the ‘command and control’ Urban Waste Water Treatment and Nitrates Directives of 1991, through the quality objectives Water Framework Directive of 2000, to today’s emphasis on the nutrient circular economy to reduce dependency on phosphorus imports and create jobs, economic opportunities and net income for farmers.

Mike Schmid, Renewable Nutrients, presented the company’s process to treat manure and recover calcium phosphate (Quick Wash®, see SCOPE Newsletter 119). He noted that with triple super phosphate currently selling at US$300/tonne (1500 $/tonne of phosphorus) the economic value of phosphate recycling is not with the product but can be with other benefits.

Joseph Ziobro, US EPA, presented the Agency’s 2016 manure Nutrient Recycling Challenge. This received 75 entries, of which 34 were selected for phase II “incubation” (see SCOPE Newsletter 121). The 34 innovator teams have been developing technology designs in Phase II based on their selected prototypes. In some cases, innovators have already built technologies and are partnering to build and test their technologies on commercial livestock operations. He also noted that phosphorus recycling is not economic alone, but can be so if combined with energy recovery. Subsidies are needed to support adopters of novel technologies, in order to alleviate innovation risks and costs. At the same time, dialogue is needed between US States concerning manure spreading limits with the aim of achieving federal water quality objectives.

Kraig Westerbeek, Smithfield Foods, the world’s biggest pig producer, explained that the company has ambitious environmental objectives, including reducing greenhouse emissions by 25% by 2025. The use of phytate and improved feed programmes and diets has enabled a nearly 50% reduction in phosphorus input per pig since the 1990’s. Smithfield notes that manure treatments (such as lagoons or anaerobic digestion) concentrate the phosphorus. Farmers have already paid for this phosphorus once, so it would be positive to recycle it to animal feed or to other value uses, subject to food safety. Smithfield’s retail and food customers are demanding sustainability: how to sell nutrient recycling as added-value in this market?

Participants noted that new approaches to fertilisation are necessary. Phosphorus is over-applied in the Chesapeake Bay catchment because farmers want to add organic matter and sulphur to soil. Nearly 4 million US$ funding is available in the catchment to develop treatments of pig, horse and chicken manures. Participants also noted that a US Senate Bill is under discussion to offer a 30% tax credit for nutrient recovery (Agriculture Environmental Stewardship Act S. 988).

Tom Bruulsema, IPNI (International Plant Nutrition Institute) presented the “4Rs” approach: fertilisation with the right fertiliser (accessible to the plant as needed), at the right rate (according to crop needs), at the right time (when the plant needs it), at the right place (where the plant can access it). Farm trials have shown that productivity is maintained, soil health is ensured, nutrient use efficiency is improved and nutrient losses to the environment are reduced. Overall in North America, since 2010, soils with elevated phosphorus levels are becoming less widespread and today soil phosphorus levels are often such that phosphorus needs to be applied to replace crop uptake, or even restored to improve productivity.

Karl Wyant, Helena Chemical Comapny (agricultural advisory), underlined that farmers’ concern is not sustainability, per se, but savings on input cost per hectare and application efficiencies. On-tractor monitoring of crop offtake, seeding control, satellite information and real-time data analysis, combined with soil phosphorus tests in several field zones can enable variable application of different fertilisers (N, P) according to crop needs in different parts of the field. This can save farmers money by optimising fertiliser use, and brings environmental benefits as a by-product.The forms in which fertilisers are delivered must be flexible and adapted to farmers’ equipment and habits in different regions: solids, liquids, different chemicals, organic and mineral.He notes that distributors and farmers are already widely using recycled nutrient materials such as composts and manures. Manures pose specific issues which are an obstacle to use: variable nutrient content (not compatible with precision farming), possible bacterial contamination and salinity.

Galen Mooso, JR Simplot, noted that the company is both a phosphate mineral producer (with two phosphate mines in the USA, <2% of world production) and a large user (in particular for potatoes, which have high P needs). He also emphasises the importance of precision agriculture, with GPS on-tractor controlled variable fertiliser application, combining different N, P, K fertilisers on the tractor according to varying crop needs across the field. A key is therefore soil phosphorus tests to understand variability of phosphorus in soils at the within-field level.

Chris Peot, DC Water, underlined the importance of sewage biosolids valorisation for water treatment sustainability. DC Water operates the world’s biggest tertiary (P-removal) sewage plant at Blue Plains, serving over 2 million population). Iron salts are used to achieve a discharge limit of 0.1 mgP/l. Anaerobic digesters convert half of the biosolids carbon to renewable energy, and the other half is recycled to farmland. The US produces a total of over 9 million tonnes/year (dry matter) sewage biosolids, containing 1-6% P (350 000 tonnes/year of phosphorus). Half of this is currently landfilled, so not recycling the phosphorus. In the DC area, sewage biosolids are mostly positively welcomed. They are branded as “DC Bloom” and recognised to improve drought resistance by restoring soil carbon, and as an economic alternative to mineral fertilisers. However, there is some opposition to agricultural use because of concerns about odours and more research is needed into persistent pollutants present in sewage biosolids. Transparency of information to the public is essential for ongoing acceptance.

Jim Elser concluded the Forum by noting that a range of initiatives are moving in the right direction and that the Sustainable Phosphorus Alliance aims to support this by networking of initiatives and actions.

Sustainable Phosphorus Alliance Forum, Washington DC, 19 May 2017, slides online at


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