Inoculation sometimes greatly improves the com position of soybean forage and seed. At the Michi gan Experiment Station there was little difference in the appearance and yield between plants with and those without root tubercles, but the pres ence of nodules increased the percentage of nitro gen in the dry matter of the leaves and stems from 1.77 to 2.78, and in the seed from 5.41 to 6.20, while the percentage of nitrogen was de creased in the roots from which nodules had been removed. At the Kentucky Experiment Station, the roots contained in the air-dry material 1.81 per cent of nitrogen when not inoculated and 2.7 per cent of nitrogen when covered with tubercles. At the Connecticut (Storrs) Experiment Station, the presence of tubercles raised the nitrogen per centage in the seed from 6.28 to 7.08.
Place in the place of soybeans in the rotation is as a cleaning or fallow crop, put ting the land in good condition for an immediately following crop of small grain, alfalfa or other crop. In the South, soybeans may be grown as a catch-crop after wheat or oats. Hopkins suggests (Illinois Experiment Station, Bulletin No. 99) sev eral rotations for the southern part of Illinois, in which the soybean may enter ; for example, four year rotation : First year, corn, with cowpeas or soybeans as a catch-crop.
Second year, cowpeas or soybeans.
Third year, wheat (with clover to be seeded in spring).
Fourth year, clover.
are many varieties of soy beans, differing chiefly in the time of maturity, size of plant, and color and shape of seed. In the latitude of Massachusetts only the early varieties mature seed, and even in Kansas an early variety is required. The standard variety in that state is Early Yellow, which matures there in about three months. Among the early varieties are Early Yel low, Ogema, Ito San and Early Brown, maturing in seventy-five to ninety days ; among the varie ties of medium maturity are Medium Black, Medium Green, Green Samara and Olive Medium, requiring a growing period of 95 to 110 days ; among late varieties are Late or Mammoth Yel low, Flat Back, Tamarat Sukun, Nalrade, Asahi and Best Green (United States Department of Agriculture No.4914). The Late Yellow matures in the Gulf states in about 130 days, while the other varieties of this late group are credited with a growing period of 114 to 166 days, the last men tioned being the latest variety on record. Gener
ally, the varieties of the second or medium-matur ing group have afforded the largest yield of for age in the northern states, especially the Medium Green. In the Gulf states. the late varieties are decidedly the most productive both of seed and of forage. The standard variety here is the Late Yellow, also known as Mammoth Yellow. Farther north, either the early or the medium varieties are used for seed production.
Harvesting.—When soybeans are grown for seed, it is necessary to harvest the plant as soon as the earliest beans ripen ; otherwise the pods split and shed the beans. Harvesting may be done by the use of a self-binder, self-rake or reaper or by the use of a corn knife. The small, early varieties are too low for the use of binder or reaper, and are best harvested for seed by a bean harvester or an equivalent home-made implement, consisting of two knives bolted to the shanks of a cultivator and sloping backward, thus cutting the plants just be low the surface. If this is not available, the small varieties most be pulled by hand.
In cutting soybeans for hay, the mower is com monly used, but it is sometimes desirable to cut the large varieties with a corn knife, in which case the cut plants are placed in loose small bundles, which are turned over just before the upper exposed leaves become crisp. A few days later these loose bundles or hands are piled in cocks, butts inward, thus making a large cock with a rather open center. The open center is then capped by the use of several bundles placed with the leaves near the center of the top of the shock. In cutting soybeans for hay, they should be past full bloom and the seed-pods formed, but not filled. For the silo the date of har vesting may be a little later, but before any seeds have ripened.
When soybeans are cut for hay with the mower, the method of curing is the same as with other legumes,—cowpeas, clover and the like. Soybeans grown for seed should he cured with as little hand ling as possible, and this handling, if practicable, should be in the early morning and late afternoon to reduce shattering to a minimum. The plants must not be hulked when damp. The threshing is done with an ordinary grain thresher, with blank concave. The seeds after threshing should not be bulked, as they heat easily, but should be kept in thin layers to insure soundness.