Seed-growing.—The hemp that is planted for seed is sown on the river-bottoms. A narrow strip along the Kentucky river produces nearly all of the hemp grown in America for seed purposes. About two quarts per acre are sown. This is often planted in hills, seven feet apart, in rows six to eight feet apart. About four stalks are permitted to grow to the hill. This hemp is carefully cultivated and kept free from all weeds and grasses. The seed is used in the making of oils for paints, for bird and poultry food, and various other purposes. The yield of seed is fifteen to thirty bushels to the acre. As much as forty dollars per acre is often realized from hemp seed. The seed must not be stored in bulk or it will heat.
Fertilizers.— The Kentucky Station has experi mented for a number of years on the use of com mercial fertilizers on hemp, and the results show that, by the use of 160 pounds of nitrate of soda per acre, three to four hundred pounds more fiber can be grown to the acre than on unfertilized land. When 160 pounds of nitrate of soda and 160 pounds of muriate of potash are used together, at least four to five hundred pounds more fiber are secured than on the unfertilized areas. Acid phos phate does not show a material increase. Nitrate of soda gives better results than does sulfate of ammonia or dried blood. The prime requirement is for nitrogen, and it should be furnished by apply ing commercial fertilizers, or by barnyard or green manures. A leguminous crop can be alter nated with the hemp, and in parts of the South this can be done in the same year.
Cutting and handling.
The first blossoms appear about the first week in July, and hemp sown April 25 will be ready for cutting about the first of Sep tember. Most of the hemp grown in Ken tncky is still cut by hand by means of a knife made especially for this purpose. However, much has recently been cut by especially designed machinery. The yield from the handcut field is greater than that from the machinery-cut field, and some farmers maintain that there is enough difference to make up for the greater expense. The heaviest fiber is found on the internode next to the ground, and if the stubble is left any length, a great quantity of fiber is lost. It usually costs about one dollar per acre to cut by machinery and three dollars per acre to cut by hand.
After the hemp is cut, it is spread evenly over the ground, the butts being placed down the hill if there is a slope. The stalks are placed in par
allel lines. In about one week it is sufficiently dry to rake up into small bundles. These bundles are tied with small stalks of hemp and are placed in shocks (Fig. 569) or stacks (Fig. 570). The Ken tucky Experiment Station has shown that it pays to stack the hemp, as the loss of fiber is not so great and the quality is much improved. Stacked hemp rets more evenly and makes a much better fiber than when shocked. In the latter case, too much of the outer layer sunburns and over-rets. The shocks are liable to blow down, greatly to the damage of the crop. The shocked hemp, however, is much less expensive to handle and can be spread out at different periods, so that the quantity retted at one time can be controlled.
If the hemp is allowed to remain on the ground too long after cutting, it will sunburn and the quality will be destroyed. It requires considerable judgment to stack hemp to avoid the sunburn. Care should be taken not to stack it before it is sufficiently dry, as it will heat in the stack with much injury to the quality.
Retting.—About the middle of November or the first of December, the hemp is taken from the stack and spread over the ground as before stack ing, to ret, a process which separates or liberates the bast. If the weather conditions are favorable, it will ret in about two months sufficiently to break. Ideal weather conditions for retting are alternate freezing and thawing, with an occasional snow that does not remain long on the ground. Early and late retting are not so good as winter retting ; and hemp retted during heavy freezes is much better than when rain-rotted. After the hemp has retted sufficiently to allow the fiber to break readily from the bards (or "hurds") it should be placed in shocks to prevent further retting. The artificial methods of retting have never been completely successful.
Breaking.—The fiber is removed or extracted from the other tissue by the process of breaking. Most of the hemp of Kentucky is still broken by the old-fashioned hand-brake that has been in use for more than one hundred years. Large sums have been spent in trying to devise machinery for this operation, but so far most of the attempts have failed. Within the last year or so, however, ma chines have been designed that promise successfully to break the hemp.