Editing Machu Picchu (section)

====Agricultural activity====
[[File:Andenes at Machu Picchu (cropped).jpg|thumb|{{Lang|es|[[Andén|Andenes (terraces)]]}} used for [[farming]] at Machu Picchu|upright=1.2]]
Much of the [[Incan agriculture|farming]] done at Machu Picchu was done on its hundreds of {{Lang|es|[[Andén|andenes]]}} (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.<ref name=":2">{{Cite journal|last=Brown|first=Jeff L.|date=January 2001|title=Rediscovering the lost city|journal=Civil Engineering; New York|volume=71|pages=32–39|id={{ProQuest|228471133}}}}</ref> The terraces also enabled irrigation, increasing crop yields, with maize likely being the main crop due to its ceremonial importance, alongside possible cultivation of potatoes.{{sfn|Reinhard|2020a|p=303}}

However, terrace farming area makes up only about {{cvt|12|acre|ha|disp=flip}} 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.<ref name=":3" />

It is estimated that the area around the site has received more than {{cvt|1800|mm}} 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 in Peru|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 drainage of excess water. Excavation and soil analyses done by Kenneth Wright<ref>{{Cite journal|title=Kenneth Robert Wright|first=Richard G.|last=Weingardt|date=19 April 2008|journal=Leadership and Management in Engineering|volume=8|issue=2|pages=87–92|doi=10.1061/(ASCE)1532-6748(2008)8:2(87)|doi-access=free}}</ref><ref name=":2"/> in the 1990s showed that the terraces were built in layers, with a bottom layer of larger stones covered by loose gravel.<ref name=":2"/> 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.{{sfn|Burger|Salazar|2004|p=101}}