||MULCHING WITH PILES OF ROCKS
Definition characters description and diffusion
Surrounding of plants with piles of rocks provides benefits to the plant including increased soil moisture retention, environmental moisture capture, increased soil fertility, increased capture of precipitation and runoff, and reduced predation of plant.
General characters description and diffusion
By carefully stacking flat rocks around sprouted plants of appropriate height, a microclimate is created within the cavitations between the rocks. Thermal storage within the stones creates temperature differentials between the air and the rocks at sunset and sunrise, causing atmospheric moisture to condense between the rocks and irrigate the soil. The soil and base of the plant are further shielded from the direct heat of the sun. Windborne sediments are captured within the cavitations, adding nutrients to the soil. For certain plants, predation of the plant is reduced by preventing animals from digging down to eat the roots.
Rockpile mulching has the added benefit of promoting more rainfall penetration into the soil (as compared to standard hard-packed desert soil), and intercepting surface runoff. Coordinated use of rockpile agriculture can lead to creation of hydrological check-dams, which channel and store water runoff. The rockpiles themselves can be used to form terracing systems.
This technique is most notable for traditional use in cultivation of the Agave species in the Southwest North America by the ancient Hohokam (see local application).
Advantages and sustainability
For applicable plant species, mortality rates due to dessication or predation are significantly reduced. Further, health and growth rate of plants are improved by increased nutrient availability and consistency of soil moisture. This allows the fruitful cultivation of well-adapted crops such as Agave in arid lands.
In control studies, agave grown using rockpiles had significantly increased biomass, resulting in more food and materials for the cultivators.
(1) Minnis, Paul E. "Agave." New Lives for Ancient and Extinct Crops. Tucson: U of Arizona Press, 2014. 116-20. Print.
(2) Fish, Suzanne K., Paul R. Fish, and John H. Madsen. "Evidence for Large-scale Agave Cultivation in the Marana Community." The Marana Community in the Hohokam World. Tucson: U of Arizona, 1992. Web.