How to grow groundnuts

Groundnuts are the second most-widely grown legume in Uganda, after beans.

There has been a substantial increase in the growing of groundnut as both a food and cash crop because of increased awareness of its value as a source of protein (23-25% content) and oil (45-52% content).

It also has the advantage of generating residual nitrogen in the soil, which benefits subsequent crops, especially when groundnut residues are incorporated into the soil during ploughing.

Despite the high local demand for groundnuts, farmers' yields continue to be low, averaging 700 per acre of dry seed. Well managed plots, using the right varieties, can yield 1-1.4 tonnes kg/per acre or more. There is no doubt about the market for groundnuts. At the moment, a kilogramme goes for sh3,500- sh5,000. Groundnut paste goes for sh6,000. To commercially produce an acre of good quality groundnuts, the average investment is about sh1.5m.

Most varieties mature in three months.

Land selection

Groundnut is not suited to growing in very dry areas or at altitudes above 1,500m (around 5,000ft). Optimum temperatures are 27-30°C for vegetative growth and 24-27°C for reproductive growth. Between 450mm and 1250mm of evenly distributed rainfall is required annually for good growth and yield.

All soils, other than heavy, are suitable for growing groundnut, but the best are deep, well drained sandy loam or loamy sand soils.

Groundnut requires adequate levels of phosphorus, potassium, magnesium and particularly calcium, which are required for maximising yield and good quality seed. You can know the actual requirements after a soil test.

For farmers who use tractors, deep turn the soil to bury residue and weeds, using a disc plough, three to four weeks before planting. In wet, low-lying areas it may be worth considering using ridges in which to plant groundnuts. The use of ridges can prevent waterlogging and improve weed control and harvesting. Ridges should be made at, or just before, sowing and they should be flat-topped.

Planting

It is good practice to purchase certified seeds from reputable suppliers. An acre takes around 50kg of seeds. It is important to be aware that some varieties of groundnut seed require a period of dormancy between harvesting and sowing and the leaflet on varieties should be consulted before sowing the same seed soon after harvesting.

Farmers should plant as soon as there is adequate moisture in the ground to ensure good germination. In general, groundnuts are planted between 15 February and 15 April during the first season and in early August for the second season. Planting early in the season helps to improve yields and seed quality and reduce the incidence of rosette disease. Long duration varieties should only be planted with the first rains in the first season.

Compiled by Joshua Kato (the editor Harvest Money) and the Vegetable Oil Development Programme (VODP)