Fungi that benefit plants

Small farmers could grow their own mycorrhizal inoculum. according to the International Center for Tropical Agriculture (CIAT) of Colombia.

Mycorrhizal fungi grow in or on some plants' roots and can help that plant take up phosphates and water, thereby increasing yields.

CIAT researchers say that for on-farm production farmers will need a cheap and relatively safe soil sterilant, a host plant and a very small amount of starter inoculum with a highly effective mycorrhizal isolate which must be adapted to local conditions. By sterilizing 25 square metres of land to a depth of 20 cm, inoculating this area and planting a host plant, the farmer can produce enough inoculum in three or four months to inoculate one hectare of cassava.

The most effective way of inoculating plants with mycorrhizal fungi is to put half of the inoculum under the cassava stake at planting time and to apply the other half in bands on either side of the plant five months later.

CIAT also says that grasses inoculated with mycorrhizal fungi and phosphate fertilizer from cheap sources can produce eleven times more dry matter than untreated pastures. (For the plants to take up more phosphates there must phosphate in the soil to begin with.)

Scientists at CIAT have been looking at ways of increasing production on the phosphate-poor, acid savannah soils of South America. They found that once mycorrhizal fungi were present in the soil most grasses were able to increase their uptake of phosphates. Results were better when rock phosphate and potassium feldspar rock were applied to grasses inoculated with funai.