KOHLRABI FOR STOCK-FEEDING. Brassica oleracea. var. caulorapa. Crueiferce. Fig. 585.
Kohlrabi is valuable for stock-feeding, not only because it contains a considerable amount of nutri ents, but because these nutrients are in a highly palatable and digestible form. In the latter respect the dry matter which it contains compares favor ably with concentrated feeds from cereals. As an offset to these qualities, however, are the facts that it is rather high in water content, thus necessita ting feeding it with dry grains or roughage ; and that it is more expensive to grow per unit of area than corn.
Kohlrabi for stock-feeding may be considered as a concentrate from the standpoint of the high digestibility of its nutrients and the large amount of net available energy de rived from them. But, in common with other food products of this class, as mangels, turnips and rutabagas, it is so watery and succulent that it can not be fed in sufficient quantities to supply the amount of nutrients required. Hence it is a part of rational practice to feed it with grain of sufficient quantity and quality to make up a balanced ration for the purpose for which it is fed. It is not, therefore, the intention to recom mend kohlrabi as a substitute for silage, or even to be fed with it, but it may he desirable to grow and feed it when condi tions of soil and climate prevail that do not permit the production of corn. It is ex tremely desirable that all domestic animals have some form of succulent food, especially in the winter, and kohlrabi is one means of supplying this need.
The American farmer has an antipathy for that kind of labor which brings into action and strain the muscles of the back. For this reason, the tendency to grow kohlrabi for stock-feeding where corn and some of the roots can be grown is not strong. However, kohlrabi does fit into into a cropping system for this purpose very admirably where it may be grown also for market purposes. If our system of agriculture becomes more intensive, perhaps kohlrabi will find a more welcome place in the rotation.
Composition and yield.
The composition of kohlrabi is very much the same as that of mangels, as shown by the following table compiled from results of analyses in Norway, where these plants are grown extensively for stock-feeding : It will be noticed that the kohlrabi is deficient in two essential matters, namely, yield per acre and dry matter content. Both of these are serious defects, as they embody the main qualities for which any forage crop may be grown. Dry matter content is the most important consideration, yet in kohlrabi this is above the general average of the production of dry matter in corn in the New Eng land states. At the Cornell station, several varie ties of kohlrabi for three years yielded a minimum of 3,570 pounds of dry matter per acre, a maxi mum of 4,540 pounds, and an average of 4,040 pounds. The yield of grain from flint corn in the same seasons was about two thousand pounds per acre, while the yield of dry matter in silage from dent corn was about four thousand pounds per acre. Thus it is seen that the yields are satis factory, but the principal drawback remains in the large amount of hand labor required in its production.
Varieties.
Not many varieties of this crop have been de veloped, and those which have been grown are mainly for table use. The three varieties grown recently at the Cornell station for stock-feeding have given the following statistical results : Other varieties which have given good results in Canada are Purple Vienna and Short-top White.
Cultural methods.
Soil.—Kohlrabi will grow and develop on a great variety of soils and under varying conditions of rainfall. In general, however, learns with a good supply of organic matter and good drainage, insur ing a constant supply of moisture, are best adapted. In 1905, at Cornell, a rather stiff clay produced 21.5 to 23.7 tons per acre for different varieties. Especially essential is a well-prepared seed-bed in order that germination may be quick and uniform, and that the plants may be invigorated by a good supply of moisture and plant-food.