Namibia has endured a seemingly longer dry spell, and many farmers label it as the hardest season compared to the previous ones, particularly since the 2012/2013 season.
However, the next rainy season has started, many farmers are now relieved because of the latest rainfall activities being observed in several parts of the country. Hearing from weather forecasting, hope in many farmers seemed to be restored. Besides that, the fact remains that climate change impact is conspicuous, and in general, rainfall activities are highly erratic in many parts of the world, and the vulnerability of the arid regions of which Namibia is part still lingers.
As a lesson learned, Namibia has had unfavourable rainfall activities all along since the 2012/2013 season, and the 2018/19 season labelled as “the worst”, it should leave farmers to wonder about the next rainy season. Although the next season is believed to be a promising one for Namibia, farmers should narrow that down to their own individual farm environment or areas and ask themselves whether they are ready to receive any amount of rain, and what its impact could be.
How do you receive rain? Is it with a rain gauge or with the soil? The most important element of rangeland productivity is soil health. This refers to the rudimentary abilities of the soil to support plant growth, hold water, and other ecological functions such as nutrient cycling amongst others. Most grazing areas in Namibia are degraded, and the two most forms of degradation are soil erosion and bush encroachment and these have resulted from improper grazing regimes, and also exacerbated by drought conditions. Simply, soil erosion is the removal of the topsoil by the action of wind and water, and bush encroachment is an accelerated increase in bush density out of balance with the other plants in an area.
The promising rain we are anticipating should be able to reach and infiltrate the soil to support plant life, especially the grass plants. This may not happen because many grazing areas in the country are degraded, bare patches have increased and widened, and the soil surfaces are hardened. With that, the soil is exposed to extreme conditions, thus, higher evaporation rates, excessive run-offs and more soil erosion can be expected. Soil erosion activities do not only remove the soil but the seeds and organic matter as well, thus, destabilizing soils. On the other hand, the soil and the grass plants in bush encroached areas may not receive sufficient moisture as rainfall will be intercepted by the bush canopies, and the bush seedlings will also be competing with grass seedlings for soil moisture.
That means, with the good rains that may be received, the rangelands may not produce to their potential or their productivity may not sustain the animals for a potentially longer period. Therefore, farmers need to invest their efforts in rehabilitating degraded rangelands by controlling soil erosion and bush encroachment. These two activities can also be done in unison. For example, when controlling bush densities by mechanical means such as “chopping down” the bush, the chopped off bush canopy can be left to cover the soil (“canopy overlaying”) as the basic tool to control soil erosion. By that, the canopy will act as a shield from extreme heat; it will provide shade, retain moisture, and block the soil particles, seeds, and organic matter blown by wind or flowing with water. Most importantly, the canopies will reduce water flow (Run-off), allowing the soil to seep in more water.
There are various ways of controlling soil erosion and they vary with landscape types and the degree of soil erosion activities. Any effort of rangeland rehabilitation should strive to use appropriate methods that will not threaten the natural productive potential of the land. Since farmers may not exactly tell how much rain they will receive during any season, it is high time that they prepare their rangelands to benefit from any amount of rain that comes. In conclusion, good rain is the one starting at the time as expected, well distributed over the season, and ultimately with an optimal rangeland yield.
* Erastus Ngaruka is a Technical Officer: Livestock Agri Advisory Services Division (AASD) at Agribank, he writes in his own capacity.
2019-10-29 07:57:18 | 2 months ago