Agriculture and Environment: Sorghum

Environmental Impacts of Production: Habitat Conversion & Degradation

The cultivation of sorghum poses severe threats to the integrity of many ecoregions around the world, including some of the most fragile.

Because of its ability to survive and produce with less water and poorer soils than most other commodities, sorghum is grown on some of the world's most delicate land.

Significant impacts on local biodiversty
In the Rift Valley of Eastern Africa, for example, land is increasingly being converted to crops such as sorghum, millet, and irrigated rice. These are now the most cultivated crops in Malawi. Habitat conversion for cultivation drastically changes the composition of the local flora and fauna.

The farming activities of rural people throughout this region are destroying and fragmenting large areas of natural habitat. This is the most important conservation issue in the area and sorghum is right in the middle of it.

Infestation by parasitic weeds
In Asia and Africa, the long-term, continuous cultivation of sorghum leads to the infestation of fields by striga, a parasitic weed. Heavy infestations by this weed can leave the land unfit for cultivation.

Striga - highly invasive & devastating
Striga can lead to declining soil fertility, and more importantly it can become so invasive that it strangles sorghum plants and makes farming unviable. In short, the areas with greatest infestations are abandoned (FAO and ICRISAT 1996).

One of the ways to reduce the impacts of striga is to plough and plant very early in the planting season before rains have started and the weed has become established. If planting is delayed for any reason, then striga becomes established and production will be severely affected.

In the early 1980s, Ethiopian troops attacked peasants in the northern part of the country with the intent to disrupt food production. Their tactic delayed planting and striga became established in the fields. This was one of the major causes of the famine of 1984-85 (Clay et al. 1985).