Cape Town | Tuesday
THERE is unlikely to ever be a single ”magic bullet” that can solve the problem of poor soils in Africa, but there are signs that genetically modified (GM) crops could be one element in a broader solution, says Professor Jennifer Thomson of the University of Cape Town.
In a submission to the national assembly’s environmental affairs committee during public hearings on genetically modified organisms (GMOs) she said the logic behind this was simple.
”Incorporating crop residues into the soil is an obvious and low-cost way of rebuilding soil health.
”Not only do the residues contain valuable nutrients, they also moderate extremes of acidity.”
However, the vicious circle of low productivity meant that just as crop yields were low so were the quantities of crop residue.
There was generally very little for the farmers to put back into the soils once their crop was harvested.
”Genetic modification is potentially a way of breaking this chain, since crops engineered to prosper in the face of drought, disease and pests, are, as something of a side effect, also going to offer greater biomass post harvest,” she said.
Evidence of the potential of GM crops in sub-Saharan Africa was already coming out of research being done by UCT.
Thomson said that for example in the case of drought tolerance, a research group was currently working to transfer genes from an indigenous ”resurrection plant” into food crops.
These plants were capable of drying up almost completely, yet resurrecting to full health when rain finally arrived.
”If the right genes could be transferred to food crops, losses through drought might be significantly reduced and most organic matter could be returned to the soil.”
Many proteins that conferred tolerance to drought also conferred tolerance to other stresses such as high and low temperature and salinity.
Thus the genes of the resurrection plant could offer multiple benefits.
The same case could be made out for GM crops that could stand up to pests and diseases.
Thus GM offered not only the prospects of greater productivity directly through increased yields, but also the prospect of larger quantities of crop residues, which could build soil fertility to the benefit of subsequent crops, Thomson said. – Sapa