Why you must plant drought tolerant soybean

Soybean also known as glycine max is a nutritious crop containing 40 percent protein and 20 percent oil both of which are vital in human and animal diet. 
With the available technology for processing soybeans at industrial and household level, soybean has become one of the most promising food crops to improve the diets of millions of people in the world.

Background
The protein in soybean is also balanced with all the essential amino acids which the body cannot manufacture.
Due to its nutritional superiority, soybean flour is often blended with cereal flours such as maize to boost their nutritional value.  The amount of proteins found in soybean is similar to animal proteins, which makes it the only substitute to animal and fish protein. 

For this reason, soybean based foods are highly recommended by nutritional specialists to children, mothers and HIV patients. 
Soybean oil is 85 percent unsaturated, comprising linolenic acid (omega 3 fatty acid) and oleic acid which have been shown to reduce the risk of heart disease by lowering serum cholesterol by 33 percent. Besides it also contains isoflavones which increase artery and heart health. Studies have also shown that regular soy food consumption can reduce the risk of rectal cancer by 80 percent, mammary tumor by 40 percent and breast cancer by 50 percent.  

Soybean breeding
Soybean breeding in Uganda is spearheaded by Prof Phinehas Tukamuhabwa of Makerere University College of Agriculture and Environmental Sciences. Seeds of Gold caught up with him and below are details of soybean value chain.
Prof Tukamuhabwa notes that the crop is increasingly becoming a cash crop in Uganda and within the region both in production and productivity.

This is clearly seen by the rapid increase in the number of industries involved in processing soybean products such as cooking oil, animal feed and processed baby food. 
The team conducts soybean breeding and value chain at Makerere University Centre for Soybean and Improvement in Makerere University Agricultural Research Institute Kabanyolo (MUARIK).

Prof Tukamuhabwa began studying and breeding soybean varieties that meet Ugandan farmers’ needs in 1990 when he was a graduate student and saw economic potential in the crop.

Giving the history of the crop, Prof Tukamuhabwa notes that soybeans reached Africa in 1858, when they were first cultivated in Egypt. Today soybeans are grown in 47 of the 54 nations in Africa, including Uganda.
Uganda is producing 180,000 metric tonnes of soybean per annum and is considered the leading producer in East Africa.

Varieties 
Over time, Prof Tukamuhabwa has released six varieties with different attributes ranging from yield capacity, seed size, maturity period and disease resistance.
The varieties include Maksoy1N released in 2004 which is early maturing in 90 days, resistant to soybean rust disease, with 17 percent oil content, small seed size and the yield rate is between two and three tonnes per hectare. 

Maksoy2N released in 2008 matures in 105 days, large seed size, 20 percent and 38 percent oil and protein content respectively with grain yield rate of two to three tonnes per hectare.
Maksoy3N released in 2010 matures in 100 days and is large seeded with oil and protein content of 22 percent and 38 percent respectively.

Maksoy4N and 5N were released in 2013 with the former maturing in 103 days and later 96 days. Both are larger seeded and the oil and protein content of 21 percent against 38 percent and 19 percent against 38 percent with yield rate ranging from two to three tonnes per hectare.
Maksoy6N released in 2017 matures in 95 days, it is larger seeded and the oil and protein content is 20 percent and 41 percent respectively with yield rate of two to three tonnes per hectare.

Seedbed preparation 
Before seedbed preparation it is advisable to clear all forms of vegetation from the field and the land may be prepared by hand hoe or animal-drawn ploughs or tractor.
Single ploughing and harrowing is recommended for preparing a suitable soybean garden. An ideal soybean seedbed should comprise fertile loam soils that are loose and well aerated to ensure rapid germination and seedling emergence which reduces weed pressure and well-drained soil fertile soil is recommended.

Seed selection
Successful and efficient soybean production requires farmers to select varieties with maturities that make the best use of the growing season in their areas. 
One can select for good yields and important characteristics such as oil and protein content.

It is important to select disease and pest free varieties and multiple soybean varieties can be planted in the same field.
Farmers can test seed germination potential by counting 100 seeds which are placed on paper towel. 

The paper must be wet and allow free water to drip for a minute then lay the wet towel on a clean surface and fold the towel over and roll it into a moderately tight tube.
Position the rolled towel on upright tube so that roots will grow downwards while shoots will grow upwards, for ease in removing seedlings during counting.

Keep the rolled towel in a warm place of between 23 and 30 degrees Celsius. And after three days open the towel and examine the seed germination rate. 
Good viable seeds are expected to have a germination rate of 90 percent, notably because germination time for most legumes is between five and seven days.

Planting
Depending on seed size, seed rate may vary between 50 and 60 kilogrammes per hectare for a recommended plant population of more than 300,000 plants per hectare.

Lower plant population may contribute to erratic stand, excessive branching, weed competition and reduced yield.
The row spacing may be from 25 to 90cm, the closer the row spacing, the higher the yield.

Soil management
In order for soybean to grow well, farmers are required to supply essential nutrients such as nitrogen, phosphorus, potassium, sulphur, calcium, magnesium, zinc, manganese, copper, iron, boron, chloride, nickel and molybdenum.

In case the soil lacks any of the above, farmers are required to apply recommended fertiliser. Once the plants start growing they will begin fixing nitrogen in the soil to make it more fertile.
Weed management 
Soybeans are particularly sensitive to weed competition during the first weeks of the season.
Farmers can employ hand weeding once the crop has fully established and this can be done twice. 

Pests and diseases
Seedling diseases are typically caused by combinations of pathogen species, notably, Phytophthora sp, Pythium sp, Rhizoctonia solani and Fusarium sp. 
Depending on moisture and temperature conditions, seedlings are particularly susceptible to diseases such as seed rots prior to germination where seedling decays between germination and emergence.

Leaf diseases
The diseases include soybean rust caused by the fungus Phakopsora pachyrhizi Sydow. 

Symptoms include small-water soaked lesions on underside of leaves, blister-like uredia with a central pore with extruding uredinospores on the lower side of the leaf. 
Bacterial blight Pseudomonas which causes soaked leaves in watery substance thereby affecting the tissue leading to yellowing. Bacterial pustule where infected plants display small, pale, yellowish green lesions with dark reddish brown centres which are mostly conspicuous on the upper leaf surfaces. 

The pests include groundnut leaf miners (webworms), bean leaf beetles, green clover worm caterpillars and stink bugs among others.

Soybean gene bank
Prof Tukamuhabwa and team are the main suppliers of seed to soybean farmers across the country.
Apart from processing quality seed, the team is preserving soybean plasm of various varieties with different colours, yellowish seeded varieties and black seeded varieties among others.

Some are of Asian origin and others are a collection of varieties from the African content. There are over 11,000 jam plasm collections at the centre.
The seed is kept under cool temperature below zero and it is in position to remain with germination vigour for over 100 years.  Most farmers in Uganda prefer Maksoy3N and 6N because they are large seeded, oil and protein content is high and they are disease resistant and high yielding.

Harvesting 
Harvesting should be done when all plants have dried and this is determined by the beans making rattling sound when shaken. Farmers are expected to thresh the clean the seed in dry condition and it must be stored in dry and cold conditions.