Last update: April 4, 2012 03:53:12 PM E-mail Print


FODDER PRODUCTION in semi-arid and arid areas



THE most important factor limiting fodder production in the semi-arid and arid areas of the Republic is the lack of sufficient moisture. Increased production is thus dependent on factors, which either increase existing moisture, or utilise it more efficiently. As irrigation water is limited the cultivation of plants such as spineless cactus, which make efficient use of available moisture is at present the most important possibility.



The possibility of propagating spineless cactus (Opuntia spp) and old-man saltbush (Atriplex nummularia) under limited irrigation, was investigated at the Agricultural Research Institute of the Karoo Region, in order to utilise their relatively low water requirements.

Three crops, namely lucerne (Medicago sativa) spineless cactus (Opuntia spp) and old man saltbush (Atriplex nummularia) were planted in a flood irrigation experiment over four seasons. A total of 36 inches irrigation water per season in 3-inch irrigations at regular intervals were applied. It is clear that more fodder and digestible nutrients per unit of water can be produced from drought-resistant fodder crops especially spineless cactus than from lucerne.

The cultivation of spineless cactus under limited irrigation was also tried out in a 200-mm rainfall area on the Carnarvon Research Station in the Karoo Region. Furrow irrigation was used with an interval of two months between irrigations where more than one irrigation was given.

It was found that the feeding value of spineless cactus on the wet basis is insufficient to supply the maintenance needs of stock, whereas old-man saltbush can supply the maintenance requirements of dry ewes and wethers. These two crops can thus be used as a basis for the maintenance of stock in times of drought. Spineless cactus can also supply the water requirements of sheep.

These crops supply succulent fodder in times of drought, thus enabling stock to make better use of other dry fodder available.

There is thus sufficient evidence that drought-resistant fodder crops, especially old-man saltbush and spineless cactus can play an important part in limiting the shortage of fodder during droughts in the semi-arid and arid areas of South Africa.



Farming in South Africa 43 (8)