AgroPractice: Up-scaling Soyabean Cultivation In Nigeria

Soya bean is a leguminous tropical plant cultivated for its seeds which is rich in high quality protein. When compared with other grains, soya bean is fortified with the highest level of protein as it contains all the essential amino acid required for human development. It is also rich in mineral, vitamins and fiber.

Soya bean is one of the cheapest forms of protein available to man globally; the amount of protein contained in soya bean purchased at a particular price is more than that obtainable in animal protein of equivalent price. Hence, soya bean is an essential tool for combating malnutrition especially protein deficiency in developing countries where animal protein is not readily available or is quite expensive for the average citizen.

Nigeria is the largest producer and consumer of soya bean in sub-Saharan Africa. Production has not been able to achieve its full potentials because the production of the crop is still being operated largely by small farm holders who grow the crop as a minor crop amongst other major crops like maize in crude ways, and all that is produced in the country is consumed locally and the country has to resort to importation of soya bean seeds and soya bean products to satisfy the demand for the product in the country.

REQUIREMENT
The growth of the plant is largely dependent on the climate and soil condition of the site of cultivation. Our country Nigeria has a very favorable climate that is ideal for soya bean to thrive. Most areas in the country receive well over 700mm of rainfall annually and that is the water requirement for the crop.

The crop can also be raised in areas that receive lesser amount of rainfall through irrigation agriculture which is a trend on the rise in the nation. In terms of soil, the plant can also survive in almost all types of soils available in the nation but the farmer should endeavor not to plant the crop on sandy soil. A well-drained soil with a slightly acidic, neutral or alkaline pH is essential for the crop to thrive as the crop cannot survive in a waterlogged environment.

VARIETY
There are numerous varieties of soya bean ideal for different climates and vegetation belt but the most common varieties are TGX 1448-2E, TGX 1485-ID and TGX 1835-10E. These varieties can be purchased from seed companies or from the Ministry of Agriculture where its viability, freedom from disease and pest is guaranteed.
Before sowing, the seeds should be treated with captan to keep them safe from soil borne diseases.

SOWING
After the land has been cleared and a seed bed has been prepared for planting, the next thing to be done is sowing. Ensure that sowing is done at the right time of the year to prevent damage of the crop due to drought and pest attack.

In Nigeria, cultivation begins in May/June when the rains begin and harvesting takes place in October/November depending on the time of sowing. Sowing can be done manually by placing 3 or more seeds in a hole in the soil and covering them with earth. Sowing can also be done using machines such as a seed drill or a planter for efficient and more uniform planting. Soya bean seed is usually planted on a seed bed or in a ridge with a conventional spacing distance of 70cm between rows and 5cm between stands.




SEED RATE
The normal soya bean seed requirement for a hectare of land is usually placed at 50kg to 60kg.

FERTILIZER APPLICATION
As a leguminous crop, it requires less amount of fertilizer when cultivated as the plant has the ability of providing its own Nitrogen to the soil through Nitrogen fixation by the nodules of the plant root. Hence, farmers need to pay less attention to nitrogen supply for the crop, as the need is supplied naturally in the right quantity.

Fertilizer containing other primary nutrients should be applied after a proper soil test has been conducted to ascertain nutrients that are deficient. The crop requires ample supply of phosphorus to enable proper root development. Phosphorus is usually applied at 30kg per hectare or an NPK 15:15:15.

WEED CONTROL
Both annual and perennial weeds attack soya bean farms necessitating farmers to carry out routine weeding. Weeding can be done manually using hoes and other crude tools or can be achieved using chemicals (herbicides). Efficient weed control has a tendency of increasing the general output of the farm.

PEST AND DISEASE
Some of the major pests that attack soya bean crop include bean flies, pod suckers, bugs, caterpillars, nematodes, silverleaf whitefly,etc. They can be controlled by using insecticides such as cypermethrin + Dimethoate 10EC at 100ml in 15 litres of water.

In term of diseases, the most destructive disease that infects soya bean crops is soya bean crop rust. Others include soya bean mosaic virus, frog eye leaf, bacteria blight, etc. In the case of disease, it is advised to destroy sick plants to control its spread. Disease occurrence can be controlled by using resistant varieties, treating of seeds before planting and practicing crop rotation.

HARVESTING
Depending on the variety, the time of planting and other factors, soya bean plant is usually harvested about 100 to 160 days post sowing. At this time, the plant should have attained complete maturity. This is usually determined when about 90% of the pods on the plant have turned brown. Harvesting is usually carried out manually using a sickle or a cutlass to cut the matured plant at the ground level leaving the root still buried in the soil. The harvested plants are then heaped on a tarpaulin and allowed to dry under direct sunlight before they are threshed.

POST HARVEST PROCESSING
Once the desired level of dryness has been achieved, the harvested plant is threshed. This can be done manually or through the use of a thresher. Once threshing has been completed, winnowing is carried out to separate the soya bean seeds from their chaff. Winnowing can be carried out using a winnower or using the power of wind.

The seeds obtained after winnowing are then stored in bags or in silos. Storage sites should be cool, dry, well ventilated and free from storage pests.