Celtic farmers were the backbone of Celtic society. Without the goods produced by farmers little else would have been possible. For instance, a warrior class cannot be supported for long by a pillage and burn approach (which is the way Caesar depicted the Celts). To the contrary, the archeological record is extremely clear. The Celts’ agricultural and pastoral farming practices were superior in many regards to other ancient societies’ farming practices.
As to agricultural practices, most farmers of that time used a wooden plow and went over fields twice to insure the soil was turned over completely. The Celts used a metal plow with a coulter which was far more durable than the wooden plow and allowed them to turn the soil over in one pass. They were also the first to develop a harvesting machine. It was pushed by oxen, fitted with knives and a box. The knives cut the grain and the box caught it….very impressive. They also used field rotation, irrigation, fertilizer, and a variety of iron implements. Their wheeled carts and roads allowed them to deliver their goods to markets quite efficiently.
The Celts also developed ways to store their products. Grains were stored in underground bins, meat was packed in salt.
Many of these practices were well in advance of other ancient societies and allowed the Celts to engage in advanced artistic enterprises, educational endeavors, and so forth because not everyone was needed to grow the food necessary to sustain life.