What regional plants can enhance the soil mix for rammed earth?

Beneficial Regional Plants for Soil Mix

Rammed earth construction in desert and arid climates requires a soil mix that can withstand extreme temperature fluctuations and water scarcity. One way to improve the soil mix is by incorporating organic matter from regional plants. Desert cottonwood (Populus fremontii) leaves and branches can add up to 10% of the soil mix’s dry weight, increasing water retention and providing thermal mass.

Soil Mix Formulation

When incorporating regional plants into the soil mix, it’s essential to maintain the right balance of ingredients. A general formula for rammed earth soil mix is 30% sand, 30% silt, 20% clay, and 20% organic matter. In desert climates, the organic matter content can be increased to up to 30% by adding regional plant material. This higher organic matter content will help improve water retention and reduce the need for irrigation.

Microbial Activity and Soil Fertility

Creosote bush (Larrea tridentata) and jojoba (Simmondsia chinensis) plants can add beneficial microorganisms to the soil mix, improving soil fertility and structure. When incorporating these plants into the soil mix, it’s essential to ensure that the plant material is properly broken down to release its beneficial microorganisms. This can be achieved through composting or using a chipper to break down the plant material into smaller pieces. The resulting soil mix will have improved microbial activity, leading to better soil fertility and reduced erosion.