Evaluating the effects of industrial hemp cultivation on soil quality in Florida

Abstract

Industrial hemp (Cannabis sativa L.) has garnered increasing attention in the United States for its environmental and economic potential, yet its effects on mineral soil health remain largely unexplored. This study assessed the impact of hemp cultivation on soil quality by examining different hemp varieties and nitrogen (N) fertilization rates across three distinct subtropical agroecosystems in Florida. Over 2 years, field experiments were conducted at three University of Florida/Institute of Food and Agricultural Sciences research centers—West Florida Research and Education Center (Dothan fine sandy loam, pH 6.25), Plant Science Research and Education Unit (Arredondo sand, pH 6.25), and Tropical Research and Education Center (Krome gravelly loam, pH 8.4)—using a randomized block design. Three hemp varieties (IH-Williams, Wife, and Maverick) were cultivated under varying N application rates to evaluate their effects on soil organic matter (OM), nutrient levels (total and available N, and total phosphorus and potassium), and potential environmental benefits, such as reducing soil nitrate-N (NO3−-N) losses in agricultural systems. Results indicated that hemp cultivation, particularly with high-cannabidiol varieties Wife and Maverick grown for flower production, significantly (p < 0.05) increased soil OM and influenced soil N dynamics. All hemp varieties significantly (p < 0.05) reduced NO3−-N concentrations, while N fertilization had varying effects on total N and ammonium-N. Such findings will contribute to developing best management practices for optimizing nutrient applications and maximizing hemp's potential in improving soil health and promoting environmental sustainability across Florida's agricultural landscapes.