Migration

Part 3 - Plows, wheels, wagons and seed drills

Early farmers discovered that plants would produce better fruit, tubers and seed when grown in loose soil but digging with wooden sticks and hoes was labourious work until someone invented the plow (plough).

The first plow was probably a tree branch with a convenient fork that was dragged through the soil. We have evidence of plowed fields from India about 2800 BCE and Europe about 3700 BCE.Until the Han Dynasty (202 BCE – 220 CE), Chinese plows were made of wood, except for a iron cutting blade. Later, the Chinese made the entire plowshare from cast iron. These were more effective at turning the soil over; bringing nutrients to the surface and burying weeds so they would not compete with the preferred plants for water, nutrients and sunlight.

By the 4th century CE, the Romans were using a wheel to support the weight of heavy mouldboard plows. This design reduced drag and controlled the dept of the furrow.

At first, oxen were used for the heavy work of pulling plows and carts because harnesses, made from flat straps across the neck and chest of the animal, pressed against a horse's trachea and restricted breathing.

The first true horse collar, developed in China during the 5th century CE, used a padded collar to distributed the load around a horse's neck and shoulders allowing the horse to use its full strength when pulling a wagon or plow.

This made horses immediately more valuable as they were 50% more powerful, faster and had more endurance than an ox so agricultural productivity increased substantially.

The horse collar spread to Europe around 920 CE, and was in general use by the 12th century. It boosted economies in Asia and Europe, reducing subsistence farming and permitting people free time for the development of trade, industry, education and the arts and the rise of market towns.

The invention of the wheel considerably improved productivity of farmers who could move heavy loads around with less effort. The oldest wheel found in Europe was simply a wooden disk with a hole for the axle. It dates from about 3000 BCE. Wheels diameters increased as users found that larger wheels would roll over uneven ground with less effort.

Iron rims, which increased the strength and durability of the wheel, were used on Celtic chariots before the Roman era.

A wheelbarrow usually had a single wheel at the front of a box and was used for short distances as the user had to lift a part of the load. The Chinese version, intended for longer journeys, had one large wheel in the middle, and the load was distributed on both sides of the wheel. The user had only to balance the load while a second person pulled it along with a rope.

A handcart, typically a two wheeled vehicle pulled or pushed by one or more people, was the most common transport vehicle as it was light and could be turned around easily.

A two wheeled cart pulled by a single horse usually had a pair of shafts, one along each side of the horse. The ends were supported by a saddle which carried a small part of the load. When the cart was pulled by two horses (or oxen or buffalo), the cart had a single pole between the pair of animals.

A wagon (or dray) was a larger, four wheeled vehicle used for longer and heavier loads. It was pulled by one or more horses, mules or oxen, often in pairs or teams. Turning a wagon was a longstanding problem as the front wheels hit the sides of the wagon as they pivoted around a pin in the middle of the axle. The front pair of wheels were often made smaller than the rear wheels permitting them to turn under the vehicle bed and the wagon body was sometimes cut away allowing them to turn in a smaller circle but increasing the risk of the wagon tipping over on rough ground.

Carriages were developed as people carriers in Roman times. First century BCE Romans used wagons where the seats were not directly connected to the axles but were suspended on chains or leather straps for a more comfortable ride.

Early farmers scattered seed by hand which often meant that plants were spaced irregularly and had to compete with one another and also with weeds which could not be removed easily. For plants like wheat, the farmer was lucky to get back two or three seeds for each one planted.The seed drill was invented in 2nd century BCE China. This multi-tube, iron seed drill sowed seeds by positioning them in the soil at precise intervals and burying them to a specific depth. This ensured that seeds were distributed evenly, allowing weeds to be remove from between the rows easily, and prevented the seed from being blown away or eaten by small animals. This greatly improved productivity by wasting fewer seeds and producing as many as nine seeds for each one planted. This provided more healthy plants from each cultivated area.

(Modern north American farmers can produced winter wheat with 22 seeds per head and 5 heads per plant, or 110 seeds per plant. Corn (maize) may have 600 seeds on each ear). While the Babylonians used primitive seed drills around 1400 BCE the technology did not reach Europe until 1566 CE when they first appeared in Venice.