The agricultural utility of lithic-mulch gardens: Past and present

The mulching of agricultural fields and gardens with stones, pebbles, volcanic ash and similar lithic materials is a variant agricultural strategy uniquely suited to the constraints of a dryland environment. While the agricultural literature contains reports on limited experiments with stone or gravel mulch, data regarding the employment of lithic mulch are lacking. This paper works to bridge this gap by comparing empirical data collected from prehistoric pebble-mulch gardens in the Galisteo Basin (New Mexico) to contemporary agricultural experiments with lithic mulch. Such past-present and experimental-real world comparisons allow us to more fully address the effectiveness of lithic mulching as an agricultural strategy. It is affirmed that lithic mulch is applied to garden plots, especially during periods of drought, in order to reduce soil erosion from wind and water, increase soil temperature to extend the growing season, increase water infiltration, and reduce the evaporative loss of water from wind and sun. The cumulative effect of this soil and water conserving technique is an increase in crop biomass and crop yield.