Hemp grows best on a loose, well-aerated loam soil with high fertility and abundant organic matter, with a pH of 6.0-7.5. Well-drained or tiled clay soils can be used, but poorly-drained clay or poorly structured soils often results in establishment failures, as seedling and young plants are prone to damping-off.
HEMP PRODUCTION (Purdue University)
Information about Loamy soil
Loam is a classification given to soil that contains relatively balanced amounts of sand, silt and clay. Loam soils typically contain less than 52 percent sand, 28 to 50 percent silt, and between 7 and 20 percent clay. Classification as a loam soil has nothing to do with the organic material it contains or where it is found. A mixture that contains almost equal amounts of silt, sand and clay is referred to simply as loam. However, if the soil has slightly more of one of these elements in relation to the others, then the classification is modified to sandy loam, clay loam, silt loam, sandy clay loam, or silty clay loam.
Sandy loam soils have visible particles of sand mixed into the soil. When sandy loams soils are compressed, they hold their shape but break apart easily. Sandy loam soils have a high concentration of sand that gives them a gritty feel. In gardens and lawns, sandy loam soils are capable of quickly draining excess water but can not hold significant amounts of water or nutrients for your plants. Plants grown in this type of soil will require more frequent irrigation and fertilization than soils with a higher concentration of clay and sediment. Sandy loam soils are often deficient in specific micronutrients and may require additional fertilization to support healthy plant growth.