RAISING INDUSTRIAL HEMP
by Joan Ruane with help from Kenex Ltd and Peter Dragla & Ridgetown College
European Union and Canada have been doing extensive experiments on “modern” methods for hemp farming for some time now. Today Australia and Germany as well as the US are very active in developing machinery that will aid in the speed of production from the harvesting to preparation of the fiber for use in finished products.
Hemp can be grown in a wide variety of soil types. It does best in sufficiently deep, well-aerated soil with a pH of six or greater. Of course, having good moisture and nutrient helps in the growth and health of the plants. If planting by seed there should be a good fine, firm seedbed to get a uniform germination. Seeds should not go into the ground until the soil temperatures have to reach a minimum of 42 to 46F. Seeds need to be planted less then 2 inches deep. Hemp seeds germinate within 24 to 48 hours and emerge in 5 to 7 days with good moisture and warm temperature. To maximize stalk yield, for fiber, seeds should be planted as early as possible.
Hemp requires high levels of nutrient availability. Typical plant needs include 80 to 100 pounds/ acre of nitrogen, 35 to 50 pounds/acre of phosphate and 52 to 70 pounds/acres of potassium. Hemp plants produce a very large amount of plant material in a short vegetative period. Much of this biomass remains in the field after harvest, were it remains in the soil, increasing organic matter and contributing to future field productivity. If plants are properly sewn normal at 200 to 300 plants per square meter, they will shade out weeds. Hemp seeds for growing hemp for fiber, should be sewn at 50 to 70 pounds/acre ideally.
Hemp is a great rotation crop as it enhances the soil with its tape roots and has a short growing season. However, because of its demand for a lot of nitrogen farmers like to plant a nitrogen-fixing crop like soybeans the year before. Hemp seeding should not follow spices or other seed crops.
Harvesting for high-quality fiber should occur as soon as the last pollen is shed, which is normally 70 to 90 days after seeding. For fiber, the crop should be cut into two feet in length, dew-retted in the field, baled and stored or processed. New combines are being developed to speed of the production as well as methods to separate the fiber and hurd. Retting has long been the method of breaking down the outer bark so that the fiber and hurd can be removed. Retting began after the stalks are cut and left in the field and it takes 14 to 21 days. The finest textile grade fiber is obtained by water retting the stalks in pools or tanks of warm water. This is where modern methods are being developed to improve the retting process and separation of the fiber.
Under commercial conditions, hemp typically produces between 3 to 4 tons of baled hemp stalks per acre. Typically, the fiber/hurd ratio is 1:3. Hemp seed yields are between 800 to 1,200 pounds/acre.
Here in the U.S. the farmers are leaning toward getting hemp plants rather than seeds, plus finding the right seeds or plants for your climate and soil is a challenge as our stock of seeds were destroyed and we are having to start over. Should you be interested in becoming a hemp farmer, you might like to go to http://www.highgradehempseed.com. Good luck and have fun but be sure to get a license!!