The question, “How has science shaped agriculture?” generates as many differing opinions as there are methods of farming. Opinions range from “only with advanced technology developed through science will farmers be able to feed the people of the world” to “only those farming practices that have been handed down from previous generations and which depend solely on nature will be sustainable,” and many variations that incorporate some features of both approaches.

The value of scientific information has become contentious these days. Scientifically-derived information is being questioned by persons who contend their own beliefs and opinions are more correct about such matters as global warming, vaccination for diseases, and managing the COVID-19 epidemic.

Dismissal of scientific information is not new however. Prior to Ferdinand Magellan’s demonstration during 1519-1521 that the earth is round by circumnavigating the globe, most people believed the earth was flat. Nearly everyone also dismissed the mathematical calculations by the Greek astronomer Pythagoras some two thousand years earlier that provided logical proof otherwise. Still today, various flat earth societies maintain our planet is flat.

Most authorities, such as biologists, contend that present-day science owes its beginnings to Aristotle, but scholars in Arab countries and Southeast Asia independently devised their own methods of science either prior to or around the same time as Greek philosophy was in its heyday. The English philosopher/scientist, Francis Bacon (1561-1626), is often credited with establishing the scientific method as the logical analysis of questions. The French biologist, Louis Pasteur (1822-1895), was one of the first researchers who applied the scientific method to successfully develop vaccines for anthrax and rabies. He also discovered that heating raw milk killed harmful bacteria through the process that bears his name, pasteurization.

Science relies on application of the scientific method. The scientific method has five steps:

1) Test a question that is based on an observation or hunch, such as “Does applying chicken manure as fertilizer prior to planting rye increase its yield?”

2) Formulate a testable hypothesis, that is, a prediction that “Rye that has been fertilized with chicken manure will out-yield rye that has not been fertilized;”

3) Test the hypothesis in a controlled experiment in which one plot of rye receives chicken manure that is disked into the soil prior to planting, and another plot that does not receive the fertilizer, but is disked similarly while keeping all other conditions similar, such as the soil type, prior cropping history, planting date, and rainfall;

4) Complete the experiment by harvesting the mature rye grain from both plots, using the same harvest method, and compare the yields by weighing the grain from both plots and calculating the difference, if any; and

5) Determine a conclusion, such as “the fertilized plot yielded more rye grain;” if a positive difference is statistically different. Replications of the experiment can be undertaken to see if the same result occurs consistently.

A sixth step can be undertaken to test additional hypotheses based on the experimental results that guides future research, such as “does varying the amount of chicken manure affect the yield of rye,” and “how does chicken manure versus cattle or hog manure affect the rye yield?” Importantly, pure science relies completely on objective methods of testing hypotheses and is devoid of opinions and beliefs.

Clearly, science has advanced agriculture, as demonstrated by the efficacy of pesticides and genetically modified organisms in producing abundant food, but these advances have led some critics to challenge if these inventions do more harm than good because of deleterious effects such as reducing beneficial soil microbes, insects, and species diversification, as well as requiring reliance on mega-corporations that control their manufacture and cost to farmers. Maybe a better question to ask is: “How has agriculture shaped science?

A rapidly growing body of findings by anthropologists, archaeologists and paleontologists indicates that our earliest human ancestors were clans of highly territorial hunter-gatherers in Africa who scavenged seeds, fruits, tubers, insects, birds, eggs, fish, and the meat, bones and skins of small animals and the carcasses of larger animals, many of which they learned to kill by coordinated hunting methods.

When the clans outgrew the carrying capacity of their African territories, they migrated in successive waves of increasingly modern humans, beginning some 50-70,000 years ago into Southwest Asia and gradually spread across all the continents except Antarctica. Ever more advanced immigrant humans interbred and displaced less sophisticated clans such as the Neanderthals.

In his Pulitzer Prize-winning book, Guns, Germs and Steel, Jared Diamond indicated that the earliest deliberate cultivation of crops occurred on the plains that intersect the Zagros Mountains of modern-day Iran, Turkey, and Iraq some 13,000-15,000 years ago. These first farmers selected the most nutritious and tasty grains, fruits, tubers, and other crops that could be planted, hoed, watered, harvested and stored for later consumption.

Through selection of plants with desirable traits, the first farmers in Asia proliferated plants that they introduced wherever they could grow them. A few thousand years later the earliest farmers emerged in Southeast Asia, Australia, the Pacific Islands, and the Americas.

Whether these new generations of humans developed agriculture independently or because they remembered from their ancestors how to grow food, farmers became ever more proficient producers of food. The development of corn with ears separate from the flowers that maize depended on for its seed, is an example of the application of careful selection by the Mayans in Central America.

Agriculture enabled humans to thrive while living in mostly permanent locations. It took fewer people to produce the food needed by an entire community, thus enabling other members of the community to specialize in trades such as construction, teaching, metallurgy, herbal medicine and so forth.

As it became necessary to remember production methods and trade agreements, the necessity for written language became clear. Eventually the standardized modern alphabet and Chinese characters led to writing as we undertake it today and replaced hieroglyphs and other drawings.

Increasingly sophisticated communities of modern humans figured out that they needed a method of counting that could replace fingers, toes, and beads. They needed to be able to count how many baskets of food were produced and to have written records of the numbers of items needed, measures of time, and so forth. Thus, the numeral system was devised and refined to become what is used today worldwide.

Eventually mathematical thinking was developed that lent to scientific discoveries. Observational thinking was replaced by systematic logical thinking and mathematical comparisons, which are essential characteristics of the scientific method.

It can be said that agriculture spawned science. How we apply the scientific method in agriculture depends on our point of view.

Dr. Mike is a psychologist at Harlan, Iowa. Contact him at: