21 January 2013

Zimbabwe: Irrigation - Africa's Missing Link

Photo: Mujahid Safodien/IRIN
Smallholder farmers from Swaziland’'s eastern Lubombo District are using conservation techniques to grow crops other than maize.


African Union Commission chairperson Dr Nkosazana Dhlamini-Zuma has re-emphasised the importance of agriculture, as "the backbone of Africa's economy". In her 2013 New Year's message released in Addis Ababa, Ethiopia, earlier this month, the Commission chairperson was bullish about the future of agriculture in Africa, expecting surpluses even and pinning hopes on the Comprehensive African Agricultural Development Programme, a blueprint to raise agricultural output exponentially.

However, despite its importance, agriculture in Africa has come under increasing pressure from climate change and global warming and other historical and structural challenges in the sector. Food production systems are faltering, as investment into agriculture remains shallow, and somewhat contrived.

There are numerous cases of legally stolen farmlands by multinational corporations across Africa. Agricultural produce by these profit-oriented organisations is mainly for export, to feed wealthy families back in Europe, America or Asia leaving poor African households poorer and hungrier.

There is little doubt food security remains one of the biggest challenges facing Africa today apart from war, disease, climate change and poverty. It is difficult to believe how Dr Dhlamini-Zuma projects a food surplus Africa in 2013 when the continent can barely feed its own, and has routinely been forced to depend on foreign food donations year in year out.

More than 60 percent of Africa's one billion people survive from hand to mouth.

Now these dangers deliver a mandate to all concerned (and ill-concerned for they also need to eat) for the need of significant urgent changes to the way that agriculture is practised in Africa. Numerous reasons support the cause for change in agriculture practice in this time of warming planets and changing climate.

FAO estimates of significantly reduced global agriculture yields of up to 50 percent by 2050 are sufficient for Africa to start drifting towards sustainable, efficient farming methods that maximise production at minimum cost. There is no time for procrastination.

Rainwater harvesting as an option for Zimbabwe

In Zimbabwe, the key challenges to increased agriculture productivity include increased rainfall and water variability resulting in frequent droughts, lack of adequate farming skills, weak adaptive capacity to climate change and funding limitations among others.

Addressing these challenges requires a suite of integrated measures that target higher agricultural output at household and national levels, as the supreme goal. I have discussed rainwater harvesting (RWH) in previous instalments, as a critical response to the shortage of water for household and agricultural use in Zimbabwe, and today will further this discussion.

The technology of harvesting rainwater, as a sustainable means of managing water resources, was last week tacitly elevated to a standard of "very high importance" after the Zimbabwe National Water Authority released shocking statistics over the national state of dam water levels.

Zinwa said while most dams in the northern half of Zimbabwe were mostly 100 percent full and spilling, those in the southern half supplying water to Bulawayo and the rest of Matabeleland, parts of Masvingo and the Midlands were severely stressed with water levels of below 15 percent. Now these are worrying numbers certain to put the spanners into any farming work especially for a people dependent on rainfed agriculture. It is important to optimise food production in those areas currently receiving an abundance of rain.

Produce from these areas will be crucial for augmenting food supplies in drought-prone regions or those experiencing periodic rainfall shortages. Although not a wholesale response, rainwater harvesting can help farmers and communities beat such shortfalls, says Mr Munetsi Mapeture, principal irrigation engineer (Midlands province) in the Ministry of Agricultural Engineering, Mechanisation and Irrigation Development.

"In Zimbabwe's situation, micro rainwater harvesting projects for irrigation can have greater impact in improving the livelihoods of rural communities as compared to major or larger irrigation projects that have huge capital requirements, which is usually not available in the developing countries," Mr Mapeture explained in a recent report drawing experiences from China, which is successfully utilising rainwater harvesting techniques.

"For emphasis, several dam projects have been completed in the country targeting irrigation but it is proving difficult to kick-start the projects because of the large amounts of money required especially in establishing the head works, such as pumping stations and conveyance pipelines." Put simply, RWH is an act of collecting rainwater, as it falls. This water is then stored in areas that limit pollution and evaporation for future domestic, agriculture or industrial use.

Through education, training, legislative support and availability of credit among other factors, Zimbabwe can effectively utilise the rainwater harvesting technology and improve household or community food production.

"Working with schools, and possibly through class projects, the benefits of rainwater harvesting can be imbibed into the minds of young students, who in turn can apply the technology at home with their parents," Mr Mapeture said.

"It is important to have young professionals with academic training in RWH to design such systems in their professional careers. Developing curricula in RWH for vocational schools will benefit those who intend to serve as technicians in installing and maintaining RWH systems."

Experiences from China

From the 1980s, China started experiencing critical water shortages which were strangling socio-economic development and environmental conservation. However, through a deliberate government policy on rainwater harvesting and the efficient utilisation of water resources, China has managed to achieve sustainable development in rural areas.

Not only have the basic water needs of the rural communities been met but water harvesting has also provided additional resources to increase agriculture production while farmers have also changed their production patterns "from monotype cereal cropping to integrated resources development".

This has greatly improved farmers' incomes and living standards. Rainwater harvesting irrigation in China is a special kind of water-saving irrigation, constituting between 10 to 15 percent of the crop-water consumption.

Mr Mapeture said this was commonly referred to as the low-rate irrigation (LORI).

With this system, water supply in the critical season that usually results in fatal crop damage due to water stress has been reduced in China, "as the crop could absorb the late-coming natural rain". Mr Mapeture said this phenomena of mid-season dry spells causing severe crop failure was the major cause of droughts in Zimbabwe, worsened by farmers' dependency on rainfed agriculture.

The role of LORI was actually to raise the water use efficiency of the natural rain, the key water provider to the crop. He said technologies being used in China could be successfully implemented in Zimbabwe and achieve good results. These methods were highly efficient at minimising evaporation and water loss, as water was only applied at the crop root zone. The rainwater harvesting irrigation systems in China are composed of catchment area, storage tank and irrigation facilities.

To reduce costs, existing less permeable surface structures such as paved highway, country road, threshing yard and the natural slope have also been used as catchment.

In the Gansu Province, the deficit irrigation system is widely used. Here water is applied only in the critical periods for crop growth, usually one application during seeding and one to two applications in the growing period. Mr Mapeture said results from using LORI in the production of maize and wheat within the province had shown an increase in output of up to 88 percent per hectare.

Significant growth had also been reported in the production of other crops such as potatoes, millet and oil sunflower.

Other forms of water saving irrigation used in China include micro-spray, bubble, drip, manual using portable can as well as irrigation through holes on plastic film.

God is faithful.


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