By Charl van Rooyen
Inoculation – the process of applying beneficial bacteria to seeds before planting – can improve crop yields and save costs on fertiliser.
Farmers earn R6 to R21 for every R1 they spend on inoculants for different crops, said Tem Odendaal, owner of the microbiological inoculant manufacturer Soygro, at a symposium on soil health and plant nutrition held by the Fertiliser Association of Southern Africa (Fertasa) in Pretoria.
Microbiological inoculants contribute to rebuilding natural soil and plant microflora and increase soil fertility for biological production. They also reduce the need for chemical products, are non-toxic, and have no withholding period.
The inoculation agents are applied in the planting furrow for foliar feeding and seed treatment. In the process, they stimulate root development, which is beneficial for nutrient and water uptake.
By inoculating soybean seed, farming profit increases by R6 for every R1 spent on inoculants. For maize, wheat and sunflowers, it’s R10, dry beans R12, groundnuts R13 and potatoes R21.
Inoculant enables the crop to fix nitrogen. Tem calculated that soybeans, yielding 3 tonnes per hectare, require a total of 280 kg nitrogen per hectare, of which 193 kg comes from the seed.
Rhizobium bacteria living in symbiosis with soybean plant roots fix about 140 kg of nitrogen per hectare. The rest comes from the previous crop and other Soygro inoculants living on the leaves and roots. The correct inoculant can produce 550 kg more seeds per hectare for soybeans than the standard treatment. The additional profit for the farmer is R3.3 million for every 1 000 hectares planted. When calculated against the expected 1 million hectares of soybeans this summer, the harvest could yield an extra profit of R4.4 billion.
After a harvest of 3 tonnes of soybeans per hectare, the farmer can usually expect 9 tonnes of maize per hectare. By inoculating the maize seed, the farmer can harvest 1000 tonnes more maize from planting 1000 hectares. The cost of the inoculant would be R693 000, but you win R3.3 million in profit.
On the approximately 3 million hectares of maize planted annually in South Africa, maize farmers could expect R12 billion more in profit. According to Tem, inoculants can also help save on nitrogen fertiliser. With a saving of just 100 kg fertiliser per hectare on 5 million hectares, 500 000 tons of nitrogen, or R5 billion in input costs, can be saved annually.
