A different modification of the prevailing rota tion of the timothy region is found in certain parts of the Pacific Northwest, mainly in western Oregon, and, to some extent, in western Washing ton. In that section, instead of following grass lands by a cultivated crop, it is more usual to sow small grain in the spring, especially oats. This is followed the next year by a cultivated crop, after which fall grain is sown. Timothy is sown with this fall grain and clover added in the spring. The reason for this arrangement of crops is found in climatic conditions. Sod land cannot be broken up and sown to corn in the spring because of the absence of summer rains. It would be too dry during the summer. The sod, therefore, must be broken in the fall. Land being thus made available for early spring operations, it is the logical place to sow oats. Because of the absence of summer rains, the oat land cannot be prepared for wheat in the fall. On the other hand, it has been found that wheat can be sown after a cultivated crop in the fall, with excellent results.
In those sections where alfalfa is the principal meadow and pasture crop, as it is in all irrigated sections of the West and is rapidly becoming so along the eastern edge of the Plains region, rota tions, when they are used at all, are arranged with reference to this crop. The land is usually left in alfalfa for a period of three to five or more years. When first broken up it is devoted either to a culti vated crop or a small-grain crop. This is usually followed by sugar-beets or potatoes (sugar-beets are not grown the first year after alfalfa because the large roots of the alfalfa interfere with their cultivation). The land is then again devoted to small grain, with which alfalfa is sown. There are numerous variations of this general type of rotation in the section in question.
In the South rotation of crops is almost unknown. In a few instances it is beginning to be practiced. One of the best rotations in any part of the coun try is widely adapted to conditions prevailing in the South. It consists of cotton, followed by corn, with which cowpeas are sown. This crop is followed by a winter crop of oats and a summer crop of cowpeas. This gives four crops in three years, leaving two blank spaces to be filled by cover-crops or green-manures, namely, between the cotton and the corn and between the cowpeas and the cotton. In this rotation permanent or semi-permanent grasses have no place. When live-stock-farming becomes general in the South, and Johnson-grass has spread over all the territory to which it is adapted, which it ultimately will do, there is a type of rotation including Johnson-grass which will be good. It closely resembles that just outlined and,
in practice, may be identical with it, but with the Johnson-grass added. It will consist of cotton followed by corn and cowpeas, these by a winter crop of oats. After the oats are harvested. the Johnson-grass is allowed to come up, and furnishes two crops of hay the first year. The next year it furnishes three cuttings. If then it is used an other year for pasture without disturbing the soil, its rootstocks come very near the surface and it can be broken up for cotton and got rid of almost as easily as Kentucky blue-grass in the North. In breaking up the sod for cotton, however, it is of the utmost importance not to plow over four inches deep, for if the rootstocks be buried deeper there is great difficulty in eradicating the grass. On farms where the first type of southern rotation is used there is always more or less permanent grass-land usually devoted to Bermuda.
As already intimated, the principal grass crop of the timothy region consists of a mixture of timo thy (Phleant pratense), Fig. 536, and red clover (Trifolium pratense), Fig. 671. This crop usually follows wheat or oats and precedes corn. The mix ture is left down by different farmers from one year to an indefinite length of time. In the shorter rotations on well-managed farms, two tons of hay per acre are usual and the very best farmers secure three and a half to four tons per acre. The longer the grass remains down under ordinary manage ment the lower the yield. After three or four years the yield usually falls below one ton per acre and the hay consists largely of weeds.
Timothy is usually sown in the fall with wheat or other fall-sown grain. It may be sown at the same time as the grain, from a special grass-seed compartment on the grain drill, in which case some farmers allow the timothy seed to fall in front of the grain hoes so that it will be covered by the drill others allow it to fall behind the dt.14 ho,s, either covering the seed later by means of a Oght harrowing or brushing of the land or leaving it to be finally covered by rain. The quantity of timothy seed usually sown under such circumstances varies from four to twenty pounds per acre, although few farmers sow less than eight or more than sixteen pounds. One peck (eleven pounds) is perhaps about the average.