Agricultural activity:
Much of the farming done at Machu Picchu was done on its hundreds of man-made terraces. These terraces were a work of considerable engineering, built to ensure good drainage and soil fertility while also protecting the mountain itself from erosion and landslides. However, the terraces were not perfect, as studies of the land show that there were landslides that happened during the construction of Machu Picchu. Still visible are places where the terraces were shifted by landslides and then stabilized by the Inca as they continued to build around the area. Terraces constructed overlooking the Urubamba River and many other springs provided fresh water for crop production and served more than 1,000 households.
However, terrace farming area makes up only about 4.9 ha (12 acres) of land, and a study of the soil around the terraces showed that what was grown there was mostly corn and potatoes, which was not enough to support the 750+ people living at Machu Picchu. This explains why studies done on the food that the Inca ate at Machu Picchu suggest it was imported from the surrounding valleys and farther afield.
It is estimated that the area around the site has received more than 1,800 mm (71 in) of rain per year since AD 1450, which was more than that needed to support crop growth. Because of the ample rainfall at Machu Picchu, it was found that irrigation was not usually needed for the terraces. The terraces received so much rain that they were built by Incan engineers specifically to allow for ample drainage of excess water. Excavation and soil analyses done by Kenneth Wright in the 1990s showed that the terraces were built in layers, with a bottom layer of larger stones covered by loose gravel. On top of the gravel was a layer of mixed sand and gravel packed together, with rich topsoil covering it. Research showed that the topsoil was probably moved from the valley floor to the terraces because it was much better than the soil higher up the mountain.
Beautiful capture of this incredible place. I always think way back to Shirley McClaine and her book "Out on a Limb" when I see anything about Machu Pichu.
Ian