As agriculture and other land use activities expand in Africa, there is need for these activities, especially agriculture to grow in a manner sensitive to water bodies. This is particularly true in this age of the Anthropocene, when human activity has become the dominant driver of the natural environment.
To safeguard and preserve water quality for tomorrow’s Africa it becomes germane to stress that at this time of its historic evolution and economic transition e.g. the advent and intensity of land acquisition by water scarce countries from Asia to grow more food for its people.
In Africa about 300 million people lack access to adequate water supply and about 313 million people lack access to adequate sanitation. Hence in addition to having to replace existing infrastructure, it will be necessary to provide a water supply and sanitation to an additional 21 million people each year on average.
Also, statistics show that agricultural food production has not kept pace with population growth in Africa. The population of Africa in 2005 was estimated at about 905 million and is expected to grow to 1.115 billion by 2015; 1.345 billion by 2025 and 1.936 billion by 2050. As a result, the nutrition position of the region is now worse than it was 30 years ago.
According to African Regional Development Report (2006), the African economy grew by 3.7% between 2003 and 2005, yet 46.4% of the population (313 million people) lived on less than US$1 per day in 2001 and the absolute number of malnourished people in Africa has increased substantially from around 88million to over 200 million in 1999 to 2001.
In much of West Africa, the average food supply (2,430kcal/day/person) is below what is regarded as the optimum level (2,700kcal/day/person). An annual investment outlay of US$4.7 billion has been suggested as being required to achieve food security in Africa. But does such investment include food security measures that are sensitive to critical ecosystems?
Hitherto, in Africa, the average rate of application of NPK fertilizer is reported to be 13kg per hectare. Factors responsible for this have included cost and scarcity of the product when needed by farmers. The implication has been the heavy post harvest losses calculated at 50per cent for fruits and vegetables and 30 per cent for root crops and tubers.
Despite the low rate of application of chemical fertilizers, recorded loses ranges from 22kg of Nitrogen (N), 2.5kg of Phosphorus (P) and 15 kg of Potassium (k) per hectare per year through soil mismanagement and ignorance. This is equivalent to US$4 billion worth of fertilizer (at United States prices) and likely US$30 billion at African fertilizer prices (Sanchez 2002; Bationo et al., 1998).
But with the increasing presence of “alien farmers or agro-investors” the scenario of low level of chemical fertilizer application will likely increase but one challenge that could remain is whether the rate of loses would be better managed to reduce leach into ground waters or run off into streams and rivers.
In the United States of America, China and parts of Europe this is already an extant nightmare as many water bodies have become polluted by Nitrates and Phosphorus from agricultural lands. Though these countries may have the resources to treat their water but the enormous costs involved are scary, hence revealing the need for Africa to safeguard its future water supplies by developing a food security strategy that is most sensitive to the environment.
One such pathway is the ecological pathway of limiting the effects of eutrophication in Africa’s waters. This is already a major problem in most African Rivers including the Nile, the Niger as well as Lakes Victoria and many others; and should in effect be controlled at this early stage.
Though other sources of pollution exist, but eutrophication by agricultural nutrients can be perverse. It often give rise to accelerated rise of algae and higher forms of plant life which has consequently led to the undesirable disturbance to the balance of organisms present in and dependent on the water and its quality.
The threat to biodiversity of both the aquatic habitat and of other species in the food chain is obvious as the water often become too low in oxygen for some species to tolerate, especially the local fish species.
The change agent to this emerging scenario is a coterie of most cost-effective measures vital in reducing the load of phosphorus and nitrate coming from farm runoff, also known as nonpoint pollution. This includes providing advisory and technical services to farmers in Africa’s watersheds.
Therefore there is need to support farmers with services that are underpinned by the principles of ecosystem based management vital in managing agricultural land in a way that is sensitive to the ecological health of nearby freshwater ecosystem thereby mitigating pollution and achieving food security etc.
The aim should be improving the management of the freshwater resource by forging a more effective connection among people and nature. And this should relate directly to the integrity, vitality, and resilience of vital freshwater ecosystem structures.
This strategy should acknowledge that the key to ecosystem management is the goal of ecological sustainability – protecting and restoring critical ecological components so that future as well as current generations will have their needs met, in this case – food security and safe water supplies.