Although religion was the principal motivator in Aztec life, farming was the principal activity. Much of Aztec life was built around farming, which was extremely necessary to sustain the growing population. Since the land that the Aztecs farmed was not fertile enough to grow enough food to support the population, the Aztecs were forced to invent methods to increase productivity. These methods included irrigation, fertilizer, and even building terraces on hills that were previously not farmable. The truly original idea, however, was that of chinampas.
Chinampas were floating gardens built on swamps. The process of making chinampas was a relatively simple one. First, canals were built through the marshes and swamps. Then, the mud from the canals was placed on mats, which were made from weeds and straw. Then, trees were planted at the corners. When these trees took root, they secured the chinampa firmly in place. Once the floating island was secure and useable, the Aztecs used it to plant their principal crop: corn. They also grew various vegetables (such as avocados, beans, chili peppers, squash, and tomatoes), and sometimes—even flowers. Unfortunately, the Aztecs had no animals or machines to help them work the land. In fact, they didn't even have plows. Thus, it was even more necessary to have soft land. Luckily for the Aztecs, the chinampas were soft enough that it was possible to plant crops with nothing but pointed sticks.
Maya
The three regions the ancient Maya lived in were very different from each other. The southern/central lowlands were covered with tropical rainforest. Rainforests do not have rich soil. This made it harder for the Maya to grow food there.
Maya farmers used a method called slash and burn before they began planting crops. Slash and burn farming was a lot of hard work for Maya farmers. First, the farmer cut down all the trees in the area he wanted to plant crops in. Cutting down the trees was the “slash part” of the slash and burn farming method. Next, he burned the tree stumps, and the trees he had cut down. The ashes from the fires mixed with the soil. The ashes made the soil rich, or fertile. Fertile means good for growing things.
After this, the farmers planted seeds in the soil and waited for their crops to grow. The crops they grew included maize (corn), squash, beans, chili peppers, and cacao (cocoa), which is used to make chocolate.
Inca
The Incas faced difficult conditions for agriculture. Mountainous terrain limited the land that could be used for agriculture, and water was sometimes scarce.
To compensate, the Incas adopted and improved upon the terracing methods invented by pre-Inca civilizations. They built stone walls to create raised, level fields. These fields formed steplike patterns along the sides of hills that were too steep to irrigate or plough in their natural state. Terraces created more arable land and kept the topsoil from washing away in heavy rains.
Although rain generally falls in the Andes between December and May, there are often years of drought. The Incas constructed complex canals to bring water to terraces and other patches of arable land.
They also made use of natural fertilizers. Guano, the nitrate-rich droppings of birds, was plentiful in coastal areas. In the highlands, farmers used the remains of slaughtered llamas as a fertilizer.