The preservation of herbage in an air-dried state for winter use is a common practice in all countries where snow covers the ground part of the year. In the northern part of the United States, east of the Mississippi, grasses and clovers are more gen erally grown for hay than any other crops. In the southern belt of states cowpeas, soybeans and Japan and crimson clovers form the chief hay crops, while in parts of the Rocky mountain region and Pacific coast states alfalfa is grown almost exclu sively as a dry fodder. On many farms where dairy ing is an important branch of farming the grain crops, cut before the seed is matured, add much to the supply of dry fodder. Some of the annual grasses, such as the millets and Hungarian grass, are grown in most of the states. These prove especially valuable because of the short period needed for their growth and the large yields given by some varieties, especially the Japanese millet. They often prove useful to supplement the regular hay crop during seasons of shortage in that crop. In some of the southern states and in Kansas and Nebraska, sorghum and kafir corn are grown considerably and field-dried as cattle feeds. These crops thrive better in regions of low rainfall than do the common grasses or maize. In the older states of the East, the stover of the corn crop has been carefully saved and utilized for many years, but in the great corn belt, up to within a few years, this part of the crop has been left in the field to be used only for grazing, while much of it was trampled by the cat tle and thus wasted. As a system of mixed hus bandry replaced exclusive grain-growing, the value of the stover was more fully appreciated, and the crop is now generally saved and used in feeding.
The preservation of forage in the form of silage has given rise to a newer branch of for age-cropping. It affords a means of preserving coarse, bulky fodders, that can be dried only with difficulty, in a small space, and thus renders them available in a succulent form when green feeds cannot be obtained. While the preservation of fodders in a closed pit was practiced in Germany before 1850, the first experiments with the silo in this country were made in 1875. At first their introduc tion was slow, but they soon found many advocates, and since 1880 their use has increased rapidly. The chief reason for the • general adoption of the silo in the northern belt of states is that corn, a crop well adapted to the climate, is the best one for preserving in the silo, coupled with the fact that silage is a cheap and valuable feed for dairy stock. Silage is not likely to replace dry fodders, yet in all of the older states it has become an important adjunct to the older system of dry feeding, particularly for the dairy.
The growing of forage crops lies at the founda tion of the practice of mixed husbandry. The rearing of live-stock and the marketing of the greater part of the farm crops in the form of animal products affords greater immediate profit and causes a smaller drain on soil fertility than does the direct sale of farm crops. Except in warm
climates, animal husbandry, and especially dairying, can be practiced successfully only where forage is grown and stored for winter use. As the market value of grains becomes higher, owing to the increasing demand for cereal foods by man, forage cropping is sure to take a more prominent place in animal husbandry, and effort will be made to produce forage of higher food value.
The great group of forage crops comprised in the grass family are all deficient in protein, while the plants of the clover family are relatively rich in protein. The tendency of late years has been to grow more forage of the plants of the clover family, and their use for this purpose is likely to increase as grain-feeds become more expensive.
Forage-cropping affords opportunity for a more complete system of crop rotation than does grain farming. On all stock- or dairy -farms a rotation should be arranged so as to include grasses and clovers, the smaller cereals, and corn grown for silage or for grain. A valuable rotation on dairy farms will be found to be a six-years plan consist ing of (1) rye sown after grass, with clover as a cover-crop ; (2) corn, with a cover-crop of rye or clover ; (3) oats ; (4) clover and mixed grasses, to be continued for three years.
Where the winters are mild and the ground is free from snow much of the time, there is great waste of fertility unless a winter cover is provided. Forage crops like rye, rape and clover, often can be grown for this purpose, and at the same time furnish valuable pasturage in the fall or spring. The adaptability of the crimson and the Japan clovers to the mild climate of the South makes these crops particularly valuable as cover-crops in that part of the country. Experiments at the Minnesota Experiment Station have shown that continuous grain-growing is very wasteful of soil fertility, not so much because of the large amount of plant-food removed by the crops as because of the decomposition of the humus and the loss from the surface soil of the soluble constituents. A rotation with cereals and clover was found greatly to reduce the loss from what took place under continuous grain-culture. Most forage crops are also directly less exhaustive of soil fertility than the grain crops, and than many of the truck crops. The grass crop serves, in a measure, as a soil-reno vator, preventing the loss of humus and of plant food by keeping the soil covered with a crop throughout the growing season. The turf and fine " aftergrowth " adds much to the fertility of the surface soil, when the meadows are plowed for cultivated crops. The clovers, and other legumes, so extensively grown as forage, take much of their nitrogen from the air and add considerable to the stores already in the soil. As a rule, forage-crop ping and the feeding of the forage to farm live stock is therefore a more economical system of farm management than the direct sale of farm crops.