Seeding

The modern farm is highly mechanized, but the goal of the farmer driving a $100,000 tractor across multiple hectares remains the same as that of a farmer scraping the ground with a pointed stick: a successful harvest.

Before you can harvest a crop, though, you’ve got to plant it.

The trick to planting is to put seeds into contact with enough water to cause them to germinate, in soil containing enough nutrients to allow them to grow. When farming first began, farmers simply spread their seeds on any likely-looking patch of ground. Some of the seeds would fall on good soil, and prosper; others might fall on rocky soil and wither away, others might fall among weeds, others might be eaten by birds. (Matthew 13:1-9, for the Sunday-School challenged.)

Eventually, farmers began trying to remove some of the hazards to good growth by first “harrowing”–pulverizing and smoothing–the soil, by dragging a tree branch over it. Then they’d use pointed sticks to make holes or scrape shallow furrows, into which they’d plant seeds.

Plowing, which can break sodded soil, was the next “big thing.”. The first plow consisted of a pointed wedge of wood with a handle for guiding it and a beam to which humans or oxen could be tied.

The Greeks and Romans improved the plow by adding a metal tip. These oxen-pulled plows, called ards, were fine for light Mediterranean soils, but as people moved north, they found much heavier soils and began developing heavier plows, some mounted on wheels. Oxen gave way to horses. Still, the design of the European plow remained basically unchanged until the Middle Ages, when two inventions were added: a “coulter,” or cutter, a blade that cut the soil ahead of the plowshare, and then, most significantly, the moldboard, the curved surface of the plow behind the plowshare, which would lift and turn over the soil and allow the plow to dig deeper. (The Chinese had invented the moldboard a thousand years earlier, but nobody in Europe knew it.)

Plows became heavier and stronger still. First the moldboard was sheathed in iron, then it was made of cast iron. When pioneers reached the North American Great Plains, they found grassland soil was so highly sodded the plows of the day had trouble cutting it. The solution was the steel plow, invented independently by John Lane and John Deere. Accompanying these changes in the plows were changes in harrows, no longer just tree branches but iron-toothed or spiked devices drawn across freshly plowed fields by horses to break up clods and level the field.

Through the Middle Ages, and later, seeds were simply scattered at random across fields. But in 1701 Jethro Tull invented a machine drill that planted seeds in rows. He reasoned this would allow farmers to cultivate between the rows of plants, making weed control easier. His drill became the foundation of almost all sowing implements right to the present day.

By the 1950s, the typical planting procedure began with plowing, to break the soil and turn it over (to remove weeds and loosen the soil so moisture can more easily penetrate it), followed by harrowing (now done with disks or spring-loaded blades). A Tull-like seed drill was used to plant the crop, followed by more harrowing to add fertilizer. Packing the soil, to ensure the seeds make good contact with trapped moisture, concluded the procedure.

But all that is changing. I spoke to Sherwin Petersen, a “mechanic by trade, farmer by choice” who’s been farming for 20 years and has developed a new seeder that can be added to a farmer’s existing cultivator or air seeder (air seeders, which came along in the 1970s, use compressed air to drive seeds into the ground). With it attached, the farmer can till, seed, fertilize and pack in a single pass, compared to as many as five passes using the “traditional” method.

Many other “direct seeders” are being developed along similar lines by companies small and large. The benefits of direct seeding include reduced fuel use and less erosion (because the soil is hardly disturbed). Best of all, remnants of previous crops can be left on the ground from year to year, which helps rebuild the soil’s organic content.

Direct seeding really just a high-tech version of the very earliest method of seeding: digging a hole with a stick, putting in a seed, and covering it up again.

In a sense, we’ve come full circle.

Permanent link to this article: https://edwardwillett.com/1995/05/seeding/

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