This section is from the book "The Planting, Cultivation And Expression Of Coconuts, Kernels, Cacao And Edible Vegetable Oils And Seeds Of Commerce", by H. Osman Newland. Also available from Amazon: The Planting, Cultivation And Expression Of Coconuts, Kernels, Cacao And Edible Vegetable Oils And Seeds Of Commerce.
The Soya bean comes from a leguminous plant originally found in a wild state in the region from Cochin China to the south of Japan and Java. It has been cultivated from very ancient times as a food plant, principally in China and Japan ; but although grown in these countries for such an extended period, its cultivation seems to have spread very slowly to the surrounding countries, and has only been introduced into India during com paratively modern times.
In the Southern part of the U.S.A., where it is now extensively grown, numerous experiments are being carried out to ascertain the varieties best suited to the different soils and climates. It is also grown in various parts of Europe, but not to any great extent.
The plant has branching hairy stems, with more or less hairy leaves, broad flowers pale lilac or violet-coloured, and three to five seeded pods covered like the stem with stiff hairs. The seeds vary in colour from whitish and yellowish to green, brown, and black, and in shape from spherical to elliptical.
Under favourable conditions the plant may reach a height of 4 feet or more. Very often more than 100 pods have been obtained from one plant, but in a field crop a good average would be 40. The flowers are self pollinated ; thus the yield is entirely independent of insects and the plant free from an important obstacle in the way of introduction to new regions. A crop of seed is ensured wherever conditions are such as to allow the plants to make the proper vegetative growth and reach maturity.
There are over 200 varieties of Soya bean, which are distinguished according to the colour, size and shape of the seed, and the time required for the plants to reach maturity. This large number of varieties can be formed into six groups - yellow, greenish-yellow, black, brown, green and white.
The yellow variety has the largest growth, and is rich in oil (17 to 19 per cent), albuminoids, carbohydrates, and nitrogen. Under average conditions it grows from 3 to 5 feet, and requires from 120 to 150 days to mature a crop of seed. The average yield should be 30 bushels per acre (600 kilograms). Under no circumstances should this seed be planted more than 2 inches deep. The crop can be readily harvested with machinery, and is frequently gathered with a grain-binder. One of the yellow varieties, the " Southern," has given very good results in Natal and in the Northern Transvaal. In West Africa also progress has been made, and a larger amount of oil has been obtained there than in Manchuria, Japan, or the United States, and, just before the war, this variety was being experimented with in East Africa and the Sudan.
The greenish-yellow, a medium late variety, is vigorous but not coarse, growing 3 to 4 feet high with numerous branches, none close to the ground.
The green is grown extensively in N. China, and, containing about 17 per cent, of oil, is considered to be one of the best eating beans. The seed is kidney-shaped, and larger in size than any other variety. This plant matures in 90 days, grows to about 3 feet high, and is very coarse.
The white variety grows abundantly in China, Dar-jeeling, Himalaya Mountains, and in India is known as Glycine Soja-Bhat. It is one of the staple foods of both countries, and contains about 16.60 per cent, of oil.
The brown matures in 110 days, and gives a large yield of seed, but its tall growth conduces to fall, and the seeds break easily on threshing.
The black bean requires a very long season in which to make its full development, and is, therefore, adapted only to the cotton-belt. The seed is rather small, elon-gated and flat, and is covered with a powdery bloom which makes it look dusty. The plant grows from 4 to 6 feet high, but has a fine stem, and so is useful for hay. It contains 16.80 per cent of oil. After all the oil has been extracted, the residue is used in large quantities by the Chinese and Japanese, who make a favourite condiment called Shoja-soy sauce- which is of a darkish brown colour, and is largely exported to Europe for sauce-making purposes.
In Japan, the Soya bean grows well in soil of rather strong character, while in Europe and America it has done well on comparatively light soils, often giving an abundant crop on soils too poor to grow clover.
In S. Carolina, excellent crops are obtained on sandy limestones or marly soils. The Soya bean is not injured by light frosts, and while possessed of excellent drought resisting qualities, it, at the same time, seems to be able to survive a period of excess of moisture better than cow-peas or even maize.
The Soya bean is especially adapted to the maize and cotton belts, where the later varieties grow exceptionally well. Generally speaking, the Soya bean requires the same temperature as maize, the soil requirements being much the same; it will make a good growth on poorer soil than maize requires, provided that inoculation is present. The Soya bean makes the best development on fairly fertile loams. Where the soil is good and a crop of hay or green fodder is desired, good results may be obtained by sowing broadcast. If, however, a crop of beans is desired it is best to plant in drills from 2 to 3 feet apart, according to the quality of the soil. When sown broadcast, about a bushel of seed is required, and when put in with a drill, from half to three-quarters of a bushel is required. When a seed crop is required, enough seed should be used to give five or six plants per foot in the row, the rows being on an average 2 1/2| feet apart.
The Soya bean can be planted any time from early spring up to midsummer. Generally, early plantings require more time to mature than late plantings, the difference in the same variety often amounting to as much as three weeks.
Under ordinary conditions, 25 to 40 bushels of seed per acre (from 1,280 to 2,100 kilograms per hectare) would be an average yield. On comparatively poor soils 20 bushels of seed per acre can generally be obtained.