This study encases two separate experiments observing hemp (Cannabis sativa L.) and soil fertility with the use of broiler litter and copper. The long-term broiler litter research plots were established in 1997 and the copper fertility research plots were not established until 2009. Both experiments use a randomized complete lock design with the broiler litter experiment composed of four replications and eight treatments at the following rates: 0, 1, 2, 3, 4, 5, 6, and 7 tons BL * ac-1. The copper experiment was designed with four replications and three treatments at the following rates: 0, 10, 20 lbs Cu * ac-1. This is the first growing season with hemp, previous crops include corn and soybeans. A protected urea nitrogen fertilizer was hand spread before planting to give 100 lbs N * ac-1 as a pre-plant application. The hemp was transplanted by hand in the established no-till field on June 13th, 2020 in 40-inch wide rows with intra-row spacing at 36 inches. The transplants were produced using feminized seed and the Queen Dream cultivar. The data collected throughout this study includes: plant height, plant tissue analysis, hemp flower bud yields, and soil analysis. In addition, bud samples were analyzed for CBD, THC, and heavy metal content. There was no statistical difference between the broiler litter treatments and hemp flower bud yields. Yield for the eight broiler litter treatments were as follows: 2443, 1969, 2413, 2605, 2281, 2569, 2737, 2725 lbs * ac-1 for the 0, 1, 2, 3, 5, 6, and 7 tons * ac-1 treatments, respectively. However, yields tended to increase with additional rates of broiler litter. The soil fertility differences between treatments remained significant for many factors, including soil phosphorus and potassium levels. The lack of statistical difference in the yields may be due to the amount of variability in the yield data. In the copper experiment, there was no statistical difference between the copper treatments and the hemp flower bud yields. Yield for the three copper treatments were as follows: 2197, 2557, 2179 lbs * ac-1 for the 0, 10, and 20 lbs Cu * ac-1 treatments, respectively. However, the higher yield, CBD, THC values of the 10 lbs Cu * ac-1 treatment deserves further study. There was still a statistical difference in soil copper levels between treatments. In both experiments, the data supports the need for repeating experiments to provide a better picture of soil fertility effects on hemp cultivation in the future.
Year manuscript completed
Year degree awarded
hemp, broiler litter, copper, soil fertility, cbd, thc
David L Ferguson
David L Ferguson
Forden, Sarah E., "Evaluating the Effects of Residual Broiler Litter and Copper in Soil on Hemp (Cannabis sativa L.) Fertility and Cannabinoid Production" (2021). Murray State Theses and Dissertations. 225.
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