How did we get so dependent on synthetic chemical fertilizer?

Jurisdictional Issues

Current government initiatives

Key problems of the Fertilizer Act and Regulations




Financing the transition


Fertilizers can come from biological or synthesized chemical sources. As with many other products, fertilizers are primarily regulated within an anti-fraud and safety context, not with the aim of supporting ecological soil management.  Preventing fraud is obviously important, as is assuring human, animal, plant and environmental safety, but at least since the Senate of Canada's Soil at Risk report (1984), there has been significant concern about the state of agricultural soils, a concern going beyond just safety.  Although there have been some modest improvements since then, Canada's series of agrienvironmental indicator reports (McRae et al., 2000; Lefevbre et al., 2005; Clearwater et al., 2016) reveal significant on-going problems.  In combination with an urgent need to optimize soil carbon sequestration as part of Canada's climate change response, there is increasing discussion of improving soil health.  However, Canada's regulatory framework for fertilizers and nutrient management has only been altered in small ways to be coherent with this emerging focus.  Essentially,  no comprehensive soil health legislation or policy exists in Canada and there are only limited regulatory structures  in place that identify (or work toward) soil health goals.

Admittedly, soil health is slippery to define and measure, but it is certainly more encompassing than the safety provisions of the Fertilizers Act.  Some integrated agroecological definitions include:

Soil health is presented as an integrative property that reflects the capacity of soil to respond to agricultural intervention, so that it continues to support both the agricultural production and the provision of other ecosystem services. The major challenge within sustainable soil management is to conserve ecosystem service delivery while optimizing agricultural yields. It is proposed that soil health is dependent on the maintenance of four major functions: carbon transformations; nutrient cycles; soil structure maintenance; and the regulation of pests and diseases. (Kibblewhite and Swift, 2008).

Healthy soils have the capacity to maintain their structure and transform carbon through SOM decomposition and nutrient cycling while supporting biological communities. For soil systems to effectively sustain food production and conserve ecological systems, soils must be managed in ways that minimize soil loss, erosion, contamination and compaction while also enhancing soil biotic populations and maintaining balanced nutrient loads. (Rotz et al.)

The “continued capacity of soil to function as a vital living system, within ecosystem and land-use boundaries, to sustain biological productivity, maintain the quality of air and water environments, and promote plant, animal, and human health” (Doran et al., 1996:11)

Main, and long-standing, criticisms of current approaches (see Goal 3, Public research) in fertilizer regulation and nutrient management include:

  • the scientific fields of soil chemistry and fertility are based on an outmoded conception of the plant - soil relationship, not an agroecology one that places much more emphasis on the roles of soil organisms and soil organic matter
  • the current regulatory environment is designed to facilitate sale of fertilizer products, not promote ecological soil management
  • excessive focus on macronutrients
  • undervalues fertility from non-chemical sources
  • overall, does not do much to facilitate improvements in soil health

The legislation does importantly reduce fraud, improve efficacy within a limited interpretation, and reduce pollution from heavy metals and persistent organic pollutants.

Other jurisdictions are substantially more advanced (see Rotz and MacRae).  This section is about improving Canada's soil health performance as it relates to fertilizer and nutrient regulation and management.

How did we get so dependent on synthetic chemical fertilizer?

Nutrients for plant growth are ubiquitous in soil and the atmosphere.  If they weren't, we wouldn't have the high levels of biomass production found in natural systems.  It is often forgotten that many natural systems are more highly productive than intensive agricultural systems, it's just that they don't necessarily produce the dominant things humans now eat.

Sixteen nutrients are essential for plant growth.  Carbon, hydrogen and oxygen (and indirectly nitrogen through soil bacteria in plant roots) are taken up from the atmosphere.  Nitrogen (N), phosphorus (P) and potassium (K) are the macronutrients and taken up primarily via soil. Secondary macronutrients - sulphur (S), calcium (Ca), and magnesium (Mg) - are needed in smaller amounts. The micronutrients iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), boron (B), chlorine (Cl) and molybdenum (Mo) are required in very limited but essential amounts. Excesses of some of this can be problematic. Nickel (Ni) and cobalt (Co) are important for some crops, such as legumes.  The focus of the fertilizer industry is primarily N, P and K (often in multinutrient mixes) since these are the most required with the highest sales volumes.

Our dependence on synthetic chemical fertilizers is tied to the industrial revolution in Europe, the growth of cities, and the associated rural depopulation. With fewer people involved in food production, a "professionalization" of agriculture was thought to be required to up production on more limited spaces to feed urban populations. What Marx referred to as the "metabolic rift" was underway, the separation of labour from basic life processes and the rupture of the cyclical flow of nutrients between residential and farming areas that had existed for centuries (see also Goal 5, Reducing food waste).

The discovery of the role of nitrogen in plant growth led in 1909 to the development of the Haber-Bosch process for creating ammonia (NH3) from atmospheric nitrogen with hydrogen from coal (now from natural gas).  The process also fueled the munitions industry, having significant impacts on WWI and WWII (for a detailed laudatory history, see Smil, 2001). In turn, post WWII, many munitions operations were converted to fertilizer production, with a significant uptick in extension support for on-farm fertilizer use. Supply and economic opportunities were driving use, and the state facilitated commercialization. Synthetic nitrogen fertilizer use went from essentially zero during WWII to over 2.5 million tonnes of actual N in 2020 (NFU and Qualmann, 2021). Canada produces significant amounts of nitrogen fertilizers, having an abundant supply of natural gas. The potassium fertilizer sector started earlier in Germany but didn't substantially exist in North America till WWI, and is based primarily on physical treatment of mined deposits rich in potassium. Canada is a major global producer of potassium fertilizer. The evolution of synthetic phosphorus fertilizers dates to the early 19th century when first bones, then later mineral deposits, were treated with sulfuric acid (for more history, see for example Russel and Williams, 1977). Canada is only a small producer of phosphorus, having a limited supply of economically accessible phosphate rock (primarily near Kapuskasing, Ontario). A long term global worry, which in theory should support reductions in P extraction and use, is that we may have surpassed peak P economically accessible deposits (see Wikipedia for an overview).

Using synthetic fertilizer products shifted farming from a more self-reliant approach to inputs, to one dependent on the market, which also fit with the development of industrial capitalism (for a history, see Albury and Schwartz, 1982).  It has also allowed farmers to shorten crop rotations and reduce organic matter additions, at least for a time, without the significant appearance of negative impacts.  As with pesticides, synthetic fertilizers have allowed farmers to implement poor farm design.  Longer-term, however, this approach has led to significant soil degradation, including erosion and productivity declines.

While there have obviously been many advantages to synthetic fertilizer use, they have essentially been overused, in part because research results frequently overestimated benefits of synthetic fertilizer by failing to contrast performance against alternative biological sources  (for a critique of earlier N studies, see for example Caldwell, 1982). Nitrogen use efficiency has been in decline for some time, and only about 17% of synthetic N applied ends up in consumed food, worse for animal than plant proteins, and the rest is largely pollution (Smil, 2001; Erisman et al., 2008).  Much of the research (and extension effort) also failed to anticipate the extent to which nutrients would be over-applied as a risk aversion strategy. In many ways, standard fertilizer recommendations were an easier way to up productivity than helping farmers improve crop rotations, cover and intercropping, and manure management and composting.  Fertilizers fit better with an industry production model. As with pesticides, synthetic fertilizers have not been priced commensurate with farm dependence on them, which encouraged until recently this over-application. This suited commercial interests, but generated significant soil and water quality problems. Equally problematic, the science behind soil tests failed to use templates and models that properly accounted for the contributions of biological sources of nutrients. Having now experienced the consequences of over-reliance on fertilizers, the actors who contributed to this overuse are now having to backtrack, with understandable resistance from the farm community that has been sold the benefits of synthetic fertilizer for some 75 years.

A further potential prop to synthetic fertilizers is the growing use (sometimes with perverse policy supports) of biomass for industrial purposes, including ethanol and biodiesel, creation of building and paper products, bioplastics and inks.  While some level of use for these purposes is appropriate, there is little to no evidence that either the market or regulators are capable of allocating biomass in a way that first assures soil health needs (see Goal 5, Sustainable biomaterials). The implicit, if not explicit, message of such thinking is that synthetic fertilizers can be used in lieu of biological material for crop fertility.

Our regulatory systems contributed to the normalization of this overuse also by discounting biological sources of fertility and the practices that enhance their availability and uptake by plants. That biological sources are variable in their nutrient composition and do not necessarily generate immediate changes in crop performance is a significant challenge for a regulatory system designed around fraud prevention.  Although there have been some modest regulatory refinements, many biological fertilizers can not be sold as such in the marketplace, identified instead as supplements, amendments or stimulants.

The fertilizer input sector is also very economically concentrated, with very significant political and economic clout which makes reducing fertilizer use more challenging (see Goal 3, Reducing corporate concentration). The industry's response to new federal emission reduction targets for the fertilizer industry - 30% below 2020 levels by 2030 - are emblematic of the problem, as the industry claims it will result in a 20% reduction in crop yield and reduce farmer net incomes.  The assumptions of their analysis are, however, highly contestable (cf. Qualman, 2021).

Essentially, we are now in a situation where overuse has contributed significantly to soil quality declines which have caused farmers to attempt to compensate by applying more of the same product, with the same poor farm designs, that caused the problem in the first place, a vicious circle of soil degradation. Once again this shows how a regulatory approach that fails to consider wider socio-economic and environmental impacts of widespread adoption of certain technologies and products, instead leaving such matters to market forces, generates significant long-term problems.  The position taken here is that synthetic chemical fertilizer use must be curtailed and ecological soil management practices enhanced, and the regulatory system has a role in helping that to happen.

Jurisdictional issues

The main authority is the federal Fertilizers Act and regulations, in place in some form since the early 1900s. The federal government regulates what is manufactured (to what standards), sold, exported and imported, traded across provincial borders, who is licensed to carry out activities, and how fertilizer  is packaged and labeled. Some fertilizers and most supplements must undergo pre-market assessment and be registered.  Other are exempt from registration (and pre-market assessment) but must still meet all the regulatory requirements and standards for safety.  Such products are still subject to post-market inspection and verification of contents and labels (for general rules of registration vs. registration exemption), see CFIA Registration Triggers).

However, the  provinces control use and disposal, which can result in discontinuities between what is covered under the Fertilizers Act and how the provinces regulate use. Because the province's are responsible for land use and environmental protection, many have Nutrient Management legislation or embed nutrient management regulations in other legislation or programming, including the Environmental Farm Plan program.  Provincial regulation is based primarily on products approved by the Fertilizers Act, and the management of manure.  Nutrient Management legislation emerged primarily because of the environmental problems created by excess fertilizer application and poorly timed application and management of manure.

Municipalities do not have any direct authority over fertilizers and nutrient management, although they make operational decisions about how much and what to apply to lands under municipal control. Because they are assigned obligations for waste management by their provinces, they may produce compost from collected food and yard waste and apply it to municipal lands.  Some may also sell compost, following provincial and federal rules (see also Goal 1, Self-provisioning, Efficiency, Improving Composting and Goal 5 Reducing food waste). They are also significant generators of septage and sewage sludge and follow rules primarily set by the provinces about their application and use.

Financing the transition

There is an urgent need to reduce the costs of farming.  Long term farm income data show that while gross returns are relatively flat, expenses have risen considerably, with net income thus in decline (Qualmann, 2019). Fertilizer and lime represent about 10% of farm operating expenses (Statisics Canada, 2020). Reducing fertilizer use saves money for farmers when part of a well designed lower input system that relies more on the internal resources of the farm for fertility while keeping yields at relatively comparable levels.  Reducing the number of approvals reduces regulatory costs, particularly staff time, though equally, the regulatory changes all require staff time investments. At the provincial level, the costs of transition depend significantly on how the province decides to ramp up transition advisory services, whether to do it all internally (the most expensive in transition terms given the low number of suitable extension staff currently in most provinces) or to make it part of the Canadian Agricultural Partnerships model with cost-sharing between farmers, the provincial and the federal governments. The key unknown in transition is cost savings associated with improved soil health and reduced pollution, particularly of water ways.  These savings may accrue to other provincial departments and to municipalities if the improvements reduce costs associated with municipal drains and water treatment facilities.