ヘンプの農法

1. Rich or fertile soil is needed. Figures from 1940-1941, say land should be fertile enough to produce 50 bushels of corn or 1,200 pounds of tobacco per acre.
2. Bottom land is perhaps best for hemp production, but rich up-land may be used.
3. The soil must not be either too droughty or too swampy.
4. The best soil for hemp is a loamy soil.
5. The soil must be well-drained.
6. For the best production of hemp, the soil, if acid, should have an application of lime.

1. Hemp must be grown in a general crop rotation as other crops are grown.
2. Hemp should be placed in the rotation after such crops as peas, beans, or clover, so that the nitrogen content of the soil will be as high as possible.
3. The physical condition of the soil must be considered for the hemp crop.
4. If hemp is grown on sloping land, it should be contour-cultivated, grown for one year only in the rotation, and the erosion controlled the same as would be necessary in corn production.

1. Nitrogen is the most important plant nutrient the farmer will need to consider. Nitrogen may be supplied through sulfate of ammonia or nitrate of soda. From 180 to 240 pounds of sulfate of ammonia or from 200 to 300 pounds of nitrate of soda per acre is recommended, depending on the soil. Sulphate of ammonia should be applied before the seed is sown. Nitrate of soda, may be used as a top dressing or sown at the time the seed is sown.
2. Phosphate should by all means be applied where it is likely to be low, especially on land that has been manured, phosphate should be added to make a well balanced fertilizer as manure is low in phosphate.
3. Lime: As a rough guide for the liming of soils to be used for hemp production, perhaps 2 tons of ground limestone is sufficient in most cases. Hemp will yield better on soil slightly alkaline, at least a small amount of lime should be applied even if the soil is only slightly acid. Of course, if the soil is very acid, larger amounts of lime will be needed. Fine lime should be used.
4. Manure: When possible, the manure should be applied to the crop just before hemp in the rotation.
5. Experiments on hemp strongly indicate that Nitrogen and Potash were needed on the plots for hemp (State College of KY, Bulletin No.55, April, 1895).

1. 1. Thorough preparation of the soil is necessary before the seed are planted. The seedbed should be very fine and mellow, and should be worked just before planting, to kill any weed seed which may have germinated since earlier workings. A seedbed considered "just right" for alfalfa should be the goal of the hemp grower (U. of Illinois, Circular 547, 1943).
2. 2. The seedbed should be level so that when the hemp is cut it will be even, easier to handle, and there will be no loss of fiber.

1. Depth: Hemp should usually be covered less than one inch, and the ground above the seed should be pressed firmly.
2. Quantity: One to two quarts of seed are required to plant an acre.
3. Re-planting: If a poor stand is obtained, it is perhaps better to plant the entire field over rather than to re-plant (of course, to plant the field over, it will need to be re-worked).
4. Labor required to thin the crop should not influence the farmer to plant too few seeds --twelve to fifteen seeds perhaps being about the right number to plant at each hill (these seed should be scattered in the hill).
5. Hill spacing: The hills should usually be spaced five feet apart, on fertile land the hills are wider apart than on poorer land, and on bottom land the hills are spaced wider than on up-land.
6. Thinning: The best time to thin the seed crop is when the plants are about six inches high, the hills should be thinned to four or five plants, and thinning should be done when the ground is moist but not too wet.
7. Cultivation: Seed hemp should be cultivated about the same as corn. The first cultivation should be given as soon as the plants are well up, even if it is not possible to get close to the hills. After the plants are 2 ﾂｽ feet high it is usually not necessary to continue cultivation.
8. Males: The male plants should be removed as soon as the pollen has blown from them (traditionally cut 18 inches above ground).
9. Harvesting females for seed: Hemp should be cut for seed at about the time the middle branches begin to shatter.
10. Shocking: Approximately forty or forty-five hills should be cut to the shock, depending on the size of the plants. The shocks should be carefully made and tied so that they will not fall or blow down. The shocks should not be allowed to stand too long.
11. Threshing: Hemp seed is ready to thresh when it is thoroughly dry.

1. One bushel of seed per acre (33 - 44 lbs) is the proper seeding for most the land that will be planted to hemp for fiber. Realize that the smaller stalk will produce the better quality of fiber.
2. Where hemp is seeded with a hand-seeder, the ground should first be cultipacked and then, after seeding is completed, the seed should be covered with a spike-toothed harrow.
3. Care should be taken, regardless of the method of seeding, to see that the seed is not covered more than one-half to one inch deep.
4. If the soil is very dry, a light roller (not a cultipacker) should be used.

1. Early seeding is desirable (the first half of April being best). In Kentucky hemp for fiber should not be seeded later than May 1. The best time for Illinois farmers to seed hemp is after oats and just before corn are planted, but not before April 20(U. of Illinois, Circular 547, 1943).
2. Experiments in early planting should consider bed preparation, frost dates, soil moisture, days of sunshine, and temperatures in the area.

1. The best time to cut fiber hemp is when the plants begin to shed pollen (males). Some farmers say cutting should be done when the plants are in bloom (females) and before the seed form.
2. This will be in late August or early September in Kentucky, giving a range of days to maturity of 120 - 140 days.