| More crop per drop |
|
 |
|
In Eastern and Southern Africa, more than 95 per cent of cropland is under rainfed agriculture. Food security depends on land management practices and rainfall distribution (Rockström 2000). Farmers in semi-arid regions have to cope with erratic rainfall and the resulting production failures and famines. Although irrigation plays an important role in food production, its possibilities of further extension seem limited since suitable water resources are scarce or too costly to exploit. |
| Photo: FAO Photo Mediabase |
|
|
Since the burgeoning population needs increased food production, more efficient use of rainfall for agriculture deserves increased attention by scientists and policy makers. More effort is required, as Kofi Annan stated, to get “more crop per drop”.
Green Water Initiative
ISRIC and FAO have started an initiative for improvement of water use efficiency in rainfed agriculture in Sub-Saharan Africa, the green water initiative.
The Green Water concept uses the term green water to distinguish the portion of rainwater that infiltrates into the soil and that is effectively used for crop growth (Falkenmark, 1993), in contrast to blue (surface) water allocated to irrigated agriculture and domestic supply, which has received a great deal more attention.
The aim of the ISRIC-FAO Green Water Initiative is to stimulate learning about how to improve Green Water Use and management in dryland agriculture. This may be achieved by making accessible, to those in close contact with farmers in Sub Sahara Africa, the wealth of information on soils, climate, water and conservation technologies, in a simple and user- friendly way. The initiative aims to unlock and disseminate biophysical and societal information and soil and water conservation experiences.
Different factors contribute to green water availability; it is determined by soil, terrain and climate, and by management.
The information gap
There is a demand for quantitative information on green water, present and potential, at regional scale from FAO, UN conventions (e.g. UNCCD), and initiatives for intensification of Sub-Saharan Agriculture such as NEPAD. Further interest was expressed by various NARS and universities in Southern Africa participating in an e-mail consultation at the end of 2002. Most recently, the WCT symposium at Bloemfontein, 9 April 2003, has emphasized the need to support farmers with information on appropriate technologies provided to farmer-supporting agencies and research and extension institutions.
A green water use project
We know from experience that, if green water management techniques are to be taken up effectively, they need to be:
- Known and understood in biophysical, economic and practical terms;
- Practicable within the existing social and economic situation - that is, matching well with existing farming systems;
- Be effective in the local situation;
- Be profitable to the farmer in the short term.
Requirements for success for the project include:
- National partners will form the backbone of the project in terms of inputs, outputs and identifying and directing the project goals;
- Farmers’ interests will be secured through a stakeholders’ steering group;
- Existing databases and networks on water, soils, soil and water conservation technologies etc. will be used, and built upon where required;
- International partners will facilitate project implementation (e.g. transnational/regional aspects, correlation) and complement local research capacity.