Biochars in the Desert Southwest: Challenges and Opportunities

Soil additions of biochar offers the possibility for improving soil quality and water holding capacity of desert soils that are used for agricultural production. A study was conducted with two texturally different soils (clay loam and sandy loam) collected near Las Cruces, NM, to assess the effects of biochar made from different feedstock (pecan shells, pecan wood trimmings, cotton gin trash and city yard waste) on soil quality and the available water capacity of the soil. Results showed the significant effect of the different biochar feedstock, with cotton gin trash biochar having the greatest impact on soil quality. Cotton gin trash significantly increased the soil organic matter and plant nutrient (P, K, Ca and Mn), but also led to elevated EC and concerns about soil salinity. Sandy loam soil benefited more from the addition of biochar in terms of water holding capacity compared to a clay loam soil. This study shows that biochar can impact arid soils significantly even in short-term and that  there is need to assess how biochar made from different feedstocks can affect arid soils.