Gauteng Smallholder September 2015 | Page 22

YOUR SOIL From page 18 surveys of some of the maize farmers who are collaborating on the biological soil management programme. They are evaluating the positive effect of SBM on parasitic nematode infestations. It is suspected that the nematode problem is also rampant in sandy agricultural soils of the Free State where maize is cultivated. Infestations in these areas are severe and have considerable economic impact. A possible reason for this is that the nematodes are too small to be seen with the naked eye and thus are not an obvious cause for poor crop yields. One very important reason for poor soil quality and ensuing nematode infections in agricultural regions is the intensive use of chemical pesticides and fertilizers during the last decades. It has disturbed the soil biology to such an extent that very low fractions of beneficial biological life remain.