Evaluating Plant Available Water in Biochar-Amended Soils—a Preliminary Study Towards Enhancing Lunar and Martian Regoliths for Plant Growth

Evaluating Plant Available Water in Biochar-Amended Soils—A Preliminary Study Towards Enhancing Lunar and Martian Regoliths for Plant Growth

Brent D. Carrillo, Maribel Dominguez, O. John Idowu, Catherine E. Brewer

Department of Chemical & Materials Engineering, New Mexico State University, Las Cruces, NM

Soils are made of two critical components that each contribute to plants’ ability to survive and grow:

mineral matter and organic matter. Though organic matter contributes only a small mass fraction of Earth’s soils, its impact is substantial: environments for microorganisms, nutrient cycling and retention, soil structure stability, water retention, and gas exchange. All of these soil qualities are important for sustainable plant growth. In this study, we amended two local desert soils (a clay loam and a sandy loam) with biochar produced from local agricultural residues to evaluate biochar impacts on soil properties. We measured soil water capacities of the amended soils using a combination of a tensiometer and a dewpoint potentiometer. These two instruments provide water content and activity over a range of hydraulic and osmotic pressures to estimate plant available water. We will use the results and methods from this study to evaluate the effects of biochar derived from astronaut solid wastes to improve the chemical and hydrological properties of Lunar and Martian regolith simulants. The goal of this project is to see if biochars can make regolith more suitable for plant production to support long-term space missions.