Assessing the effects of smallholder intensification through improved water management beyond “Business as Usual”: a multi-facet lens on sustainability [Abstract only]

In sub-Saharan Africa small scale irrigation is developing rapidly. Whilst emphasis for development is mainly placed on water resource availability and access for irrigation, less attention is paid to adoption of water lifting and management technologies, its relation to irrigation labour, profits and long term soil fertility. The dynamics of both the nutrient and the production cycle can be significantly affected when new water lifting and management practices are introduced. The objective of this study is to evaluate the effect of different water lifting (solar, manual and fuel pumps) as well as water management methods on irrigation labour, nutrient balances and profits under supplementary and full irrigation practices of vegetables in two regions of Ethiopia. Farmers were grouped into four water management treatments: irrigation based on soil moisture monitoring, using a mechanical scheduling device (i.e. FullStop), standard crop water requirements (CWR) and traditional farmers practice (FARM). Results show that manual water lifting devices are profitable under supplementary irrigation but require best management packages, such as optimal irrigation scheduling, to boost production per ha. This in combination with viable market prices could ensure that small scale irrigation remains profitable when full irrigation is supplied. One of the main explanatory variables is the irrigation labour which is often forgotten to be a significant costing factor. Solar PV pump technologies show a high potential for Ethiopia as the labour reduced by 38% compared to manual water lifting devices. When farmers had access to irrigation information, vegetable production using manual water lifting technologies turned into a profitable business as long as its effect on irrigation labour translated into proportional yield increases. For example, farmers increased irrigation for onion by 42% resulting in yield increases by 85%. However, the effect of irrigation scheduling on crop – water productivity and profits were highly variable depending on the fertiliser farmers used. Results show the importance of a recommended water management and fertiliser package to ensure sustainable intensification through irrigation development achieving crop productivity and profits gains whilst reducing potential environmental effects.