Hemp (Cannabis sativa) came into prominence as a strategic war crop shortly after United States' imports of abaca and sisal were cut off from the Philippines and the Netherlands Indies. Production of hemp in the United States was expanded from about 3,000 acres annually during the period of 1939 to 1941 to 146,000' acres in 1943.
Most of the additional acreage was planted in Minnesota, Iowa, Illinois and Indiana where farmers had little or no experience with hemp. Moreover, prior to the war period the minor economic importance of the crop, even in the old hemp-producing states of Kentucky and Wisconsin, had practically precluded the expenditure of much effort on experimental work to determine the response of the crop to different soil and management conditions. Thus, at the time the emergency arose, our knowledge of hemp growing was rather limited.
The experimental work reported in this bulletin was undertaken primarily to obtain information on the effect of soil types and soil management practices on the yield of hemp. Data are presented to show the effect of soil types, previous crops, time of plowing and method of planting on the yield of hemp, the effect of hemp on the yield of the following crops of hemp and corn, and the relative yields of hemp and corn.
Vessel, A. J. and Black, C. A.
"Soil type and soil management factors in hemp production,"
Research Bulletin (Iowa Agriculture and Home Economics Experiment Station): Vol. 28
, Article 1.
Available at: https://lib.dr.iastate.edu/researchbulletin/vol28/iss352/1