In a realistic scenario, where not everyone gives up eating meat, where some in the developing world eat more like us, and where food waste is not zero, feeding 9+ billion people will require a lot more food. Ideally, this additional production would be from existing cropland, with better input efficiency, and fewer off-farm effects. How are we going to do this, both in currently high-yield agriculture and where significant yield-gaps exist? This is the topic of an important book chapter from Hunt, Kirkegaard, Celestina, and Porker (2019): Transformational agronomy: Restoring the role of agronomy in modern agricultural research.
The authors believe that agronomy and agronomists have a crucial role to play in increasing crop yields. Because they are generalists, they can lead research and Extension teams, integrate advancements from a wide range of disciplines, evaluate potential solutions, and provide support for farmers. In short, they argue for a reinvigorated role for agronomists, one that will provide transformation of crop production through incremental change. For research agronomists, it is a must read, for commercial and extension agronomists, a good read, and for anyone in agriculture, an interesting read. Here is my summary with some added points.
First, the challenge:
“Producing enough food to keep prices sufficiently low so that the poorest citizens of the globe can reasonably afford it while also keeping growers in business.”
Rather than a grand challenge, this is a grind challenge (Madhavan, 2022), a low profile, incremental, “magnificently mundane” task, achieved by many interacting parts, one that is an overlooked by those not involved in its day-to-day struggle.
Then the question: How do we do this?
Hunt et al. propose we do it just as we have done it over the past, by yearly incremental gains in yield from a combination of factors. To achieve this, the role of agronomy is critical.
What is agronomy?
Many people don’t know. It is the science and practice of understanding how agricultural systems work in order to improve production, profitability, and sustainability. This understanding is reductionist and mechanistic, in the good sense of those terms. And it encompasses genetics, soil, climate, economics, statistics, and management factors. Agronomists are involved with crop production, but, as Hunt et al. state, must also be aware of “on-farm logistics, economic realities, and social and cultural norms.”
As generalists who understand many components of crop production, agronomists are uniquely equipped to direct and integrate research and extension efforts. However, this integrating role of agronomy has been lost recently and must be restored (See Figure 2).
The paper likens agronomy to engineering, rather than science. Agronomy adopts an engineering approach to problem solving. Engineers integrate and apply knowledge to solutions. They use the results of science when available, but when understanding is lacking, they figure out ways around this obstacle, often through shortcuts developed through observation and measurement (Hammack and Anderson, 2022). Agronomists engaged in agronomic engineering do the same, managing soil fertility without full knowledge of all that is going on in the soil, or recommending pest management based on observed economic thresholds with incomplete understanding the pest population dynamics.
Having been an engineer before I became an agronomist, this makes sense to me. My engineering textbooks were full of tables developed from observation and measurement, and not from fundamental understanding of physics or chemistry. Understanding is used to manipulate observations, but not to give practical tools. I used to say I was a recovering engineer but have realized that I am still an engineer in the way I think and work; only the focus has changed. We need this engineering approach not just in agronomy, but also in pest management (Walter, 2005) and other fields of agriculture.
Incremental or transformational change?
The call for transformational change is everywhere and usually means drastic change as soon as possible. The Hunt paper argues that, over time, yearly, incremental yield gains add up to transformational change. For example, Australian wheat yields gained an incremental 1.1-1.2% per year from a combination of small gains and interactions from breeding, pest, nutrient, soil, and crop management. When viewed over 30 years, these gains are transformational (Hunt et al., 2019; Kirkegaard, 2019). They are also the annual gains we need over the next 20 years to keep up with food demand. Rather than dismiss these small annual changes as business as usual, we should view them as the proven way to desired change.
This incremental transformation is rarely noticed because it happens so gradually but is the way most change happens (Berman and Fox 2023). It avoids the turmoil and failure of large, quick changes, and corrections can be made as needed. “Gradualism does not support the status quo, in fact it results in the opposite, steady progress over time.” (Kozlov, 2023)
“Disruptiveness is not inherently good, and incremental science is not necessarily bad,” Kozlov, 2023
The productive combination of slight management changes in various fields, this is what agronomists do. They are engineers of agriculture, putting together a cropping system from plant and animal science, soil science, meteorology, economics, etc. They put together systems of systems. “This makes agronomists unique in the field of science—most other scientists specialize deeply within these disciplines.”
Identifying constraints and solutions
The grind challenge of year-after-year modest yield increases requires:
identifying true constraints and then,
finding solutions to those constraints.
For efficient use of increasingly scarce funding, we must accurately identify the real and largest production constraints. This requires testing, first in crop models when feasible, then in experimental plots in relevant locations, and finally in farmers’ fields.
Identifying true constraints, prioritizing them, and then finding solutions requires farm data, experiments, and analysis. Too often, however, solutions related to a specific discipline are suggested to address constraints without such an analysis to promote a specific solution or concept. Using arbuscular mycorrhizal fungi is given as an example of a solution that was oversold by specialists in place of real needs for sustainable intensification (Ryan et al., 2019). Here, agronomists, with their broad views of crop production, can see the limitations of narrow disciplinary interests or of pure novelty.
“It is easier for researchers to adopt a narrative that places their discipline as central to deliver transformational change than it is to work with other disciplines and generalists to solve properly defined and quantified constraints.”
Discipline-specific knowledge is still required. This is where research agronomists (as opposed to commercial and extension agronomists) should lead and integrate teams working on the challenge.
In agriculture, there are no solutions. There are only tradeoffs. Paraphrase of Thomas Sowell.
Even where we find synergies in crop production, there will often be tradeoffs outside of the synergistic components, i.e. the planting and harvest complications of grain-legume intercrops. Agronomists are used to acknowledging and weighing these inevitable tradeoffs. In addition, they can bring in the social and economic barriers when relevant.
Even while global grain yields have been increasing yearly by incremental bits, so too agronomy has changed. The agronomy used in the Green Revolution was different from what I learned in college, which is different from today’s agronomy. The building blocks of agronomy are improved crops, fertilizers, pesticides, irrigation, and management of these in the field. They remain the same, but breeders now have better tools, fertilizers and pesticides are different and managed better (Fernandez-Cornejo et al., 2014), and awareness of off-farm effects and the tradeoffs in the use of these tools has increased. By incremental steps, agronomy has been transformed in the same way as grain yields. This paper is a clear, well-argued call to restore agronomy to its useful position within agriculture research.
Berman, G., and A. Fox. 2023. Gradual: The Case for Incremental Change in a Radical Age. Oxford University Press, New York.
Fernandez-Cornejo, J., R.F. Nehring, C. Osteen, S. Wechsler, A. Martin, et al. 2014. Pesticide use in US agriculture: 21 selected crops, 1960-2008.
Hunt, J., Kirkegaard, J., Celestina, C., & Porker, K. (2019). Transformational agronomy: Restoring the role of agronomy in modern agricultural research. In J. Pratley, & J. Kirkegaard (Eds.), Australian agriculture in 2020: From conservation to automation (pp. 373-388). Australian Society of Agronomy. http://agronomyaustraliaproceedings.org/index.php/special-publications
Kirkegaard, J.A. 2019. Incremental transformation: Success from farming system synergy. Outlook Agric 48(2): 105–112. doi: 10.1177/0030727019851813.
Kozlov, M. 2023. ‘Disruptive’ science has declined — and no one knows why. Nature 613(7943): 225–225. doi: 10.1038/d41586-022-04577-5.
Ryan, M.H., J.H. Graham, J.B. Morton, and J.A. Kirkegaard. 2019. Research must use a systems agronomy approach if management of the arbuscular mycorrhizal symbiosis is to contribute to sustainable intensification. The New Phytologist 222(3): 1176–1178.
Walter, G.H. 2005. Insect Pest Management and Ecological Research. Cambridge University Press.