The distribution of stone on the surface of gardens to increase yield is called stone mulching or lithic mulching. This technique was applied in prehistoric times on almost all continents, but was very limited in space and time and adapted to local conditions (Lightfood 1994). It was even more restricted to arid and semi-arid ecosystems of South America, North America, Africa, and in the Near East. Only a few applications of the technique are known from sites with a humid climate, e.g. New Zealand. Lightfood (1994) describes the technique as a specific niche adaptation for sites which otherwise could not be used horticulturally or agriculturally.
Bork, Hans-Rudolf; Mieth, Andreas; and Tschochner, Bernd
"Nothing But Stones? A Review of the Extent and Technical Efforts of Prehistoric Stone Mulching on Rapa Nui,"
Rapa Nui Journal: Journal of the Easter Island Foundation: Vol. 18
, Article 5.
Available at: https://kahualike.manoa.hawaii.edu/rnj/vol18/iss1/5