THE ANDEAN PEOPLE AND THEIR HARVEST.

The Incas, and the civilizations before them, were masters of their harsh climate as they build on knowledge developed over about 11,000 years of farming in the highlands of the Andes.
The daytime calendar was very important to them, since they depended on it to fix the days of planting. The night time calendar or lunar calendar marked the days of all festivals.
The Andes are some of the tallest mountains in the world. Yet the ancient Andean people obtained harvests from the sharp slopes and its intermittent waterways.
The Andean civilization is one of the five pristine civilizations worldwide which were not derivative from other civilizations. Most Andean crops were likewise pristine and not known to other civilizations.
The Andean people employed stones of different heights, widths and angles to create the best structures of water retention and drainage systems. The stone retaining walls absorbed the heat during the day and slowly released it to the soil as temperatures plunged at night, keeping sensitive plant roots warm during the frosty nights and expanding the growing season.
The Andean people also built cisterns and irrigation canals that snaked and angled down and around the mountains. They cut terraces into the hillsides and filled them with dirt, gravel and sand, and made them progressively steeper, from the valleys up the slopes. The terraces were extremely efficient at conserving scarce water from rain. In this way the whole hill was brought under cultivation.
During the Inca civilization, the system of terraces covered about a million hectares throughout the Peruvian highlands that fed the vast empire. The Inca terraces are even today the most sophisticated in the world.
Staple crops from about 1000 meters to 3900 meters were the different varieties of potatoes. Quinoa was grown from about 2300 meters to 3900 meters. Maize was the principal crop grown up to an elevation of 3200 meters in favorable locations. Cassava (yuca) was a major crop of the lowlands.
In addition to these staple crops the andean people of the Inca empire cultivated a great variety of exotic fruits, vegetables, spices and medicinal plants. Passion fruit (maracuya) can be grown from 2000 to 3200 meters, mountain papaya from 500 to 2700 meters, naranjilla or lulo from 500 to 2300 meters, and  the golden berry or ciruela from 500 to 2800 meters.
The Andean people of today are rebuilding the terraces and irrigation systems and reclaiming traditional crops and methods of planting. Ancient agricultural techniques are more productive and more efficient in terms of water use and offer simple solutions to help protect communities' food supply in the face of climate change. Glacial melt and the seasonal rains are already affected by it.