Intercropping in Maize Farming

In Africa maize does well when intercropped with beans or other legumes. The intercropped legumes should be sown at the time of first weeding in order not to crowd out the young maize plants. Since maize is a heavy feeder and takes considerable nutrients out of the soil, it can only be grown continuously on the richest soils or when heavily fertilized. Recommended legumes for intercropping in Kenya are: beans, pigeon peas, cowpeas, groundnuts and soybeans.

Other crops that have been tried with varying success include:

1.    Potatoes

2.    Cassava

3.    Pumpkin

Intercropping maize with beans and other legumes regulates pests (leafhopper, leaf beetles, stalk borer, and fall armyworm) and increases the land utility. Intercropping Canavalia (Canavalia spp.) with maize improves soil productivity.

Intercropping maize with beans and squash enhances parasitism of caterpillars. This practice increases food sources for beneficial insects whereby increasing abundance of natural enemies. The intercropping system of maize-beans-squash is a low input and high yield strategy in the tropics. Maize yield is increased by as much as 50% over monoculture yield. Although the yields for beans and squash are reduced, the overall yield for the 3 combined crops is greater than when grown separately in monocultures.

Push-pull Desmodium (Desmodium uncinatum) and molasses grass (Melinis minutifolia) when planted in between maize rows keep the stem borer moths away. These plants produce chemicals that repel stem borer moths. In addition desmodium suppresses the parasitic witch-weed Striga hermonthica.

Napier grass (Pennisetum purpureum) and Sudan grass (Sorghum vulgare Sudanese) are good trap crops for stem borers. Napier grass has its own defence mechanism against crop borers by producing a gum-like-substance inside its stem, this prevents larva from feeding and causing damage to the plant. Both grasses attract stem-borer predators such as ants, earwigs, and spiders. Sudan grass also increases the efficiency of natural enemies, in particular parasitic wasps, when planted as border crops.

Alternative uses of maize in mixed cropping

1.    Shading of vegetable crops by planting single rows between vegetables in areas of high intensity of sunshine can increase yields of intercropped vegetables.

2.    Use as support for runner beans for export or local consumption.

This is where we will be ending our discussion for today. Remember to share your comments, views and opinions.