Livestock water productivity in the Blue Nile Basin: assessment of farm scale heterogeneity A. Haileslassie A,C , D. Peden A , S. Gebreselassie A , T. Amede A,B , A. Wagnew A and G. Taddesse A A International Livestock Research Institute (ILRI), PO Box 5689 Addis Ababa, Ethiopia. B International Water Management Institute (IWMI), PO Box 5689 Addis Ababa, Ethiopia. C Corresponding author. Email: a.haileselassie@cgiar.org Abstract. A recent study of the livestock water productivity (LWP), at higher spatial scales in the Blue Nile Basin, indicated strong variability across regions. To get an insight into the causes of this variability, we examined the effect of farm households’ access to productive resources (e.g. land, livestock) on LWP in potato–barley, barley–wheat, teff–millet and rice farming systems of the Gumera watershed (in the Blue Nile Basin, Ethiopia). We randomly selected 180 farm households. The sizes of the samples, in each system, were proportional to the respective system’s area. Then we grouped the samples, using a participatory wealth ranking method, into three wealth groups (rich, medium and poor) and used structured and pre- tested questionnaires to collect data on crops and livestock management and applied reference evapotranspiration (ET 0 ) and crop coefficient (K c ) approaches to estimate depleted (evapotranspiration) water in producing animal feed and food crops. Then, we estimated LWP as a ratio of livestock’s beneficial outputs to water depleted. Our results suggest strong variability of LWP across the different systems: ranging between 0.3 and 0.6 US$ m À3 year À1 . The tendency across different farming systems was comparable with results from previous studies at higher spatial scales. The range among different wealth groups was wider (0.1 to 0.6 US$ m À3 year À1 ) than among the farming systems. This implies that aggregating water productivity (to a system scale) masks hotspots and bright spots. Our result also revealed a positive trend between water productivity (LWP and crop water productivity, CWP) and farm households’ access to resources. Thus, we discuss our findings in relation to poverty alleviation and integrated land and water management to combat unsustainable water management practices in the Blue Nile Basin. Additional keywords: animal feed, Ethiopia, farming systems, land use, poverty, water depletion. Introduction At the beginning of the third millennium there is a growing concern that water will be one of the limiting factors for increased food production (Bessembinder et al. 2005; Steinfeld et al. 2006). Thus, water must be used more productively (Rosegrant et al. 2002). Initially, this concept of water productivity (WP) applied to agronomic trials and is defined as crop yield (in kg or $US) per cubic meter of water depleted (Renault and Wallender 2000). Recently, it has been recognised that livestock feed production depletes large amounts of global fresh water, and consequently, the concept of increasing livestock water productivity (LWP) is emerging (Peden et al. 2006; Steinfeld et al. 2006). Livestock require a great deal of water for their feed (Steinfeld et al. 2006). It is estimated that the growing demand for animal feed currently depletes more than 1Â 10 12 m 3 of water per year. This is, approximately, one seventh of the global water depletion for agriculture (Peden et al. 2007). Given the increasing demand for meat and animal products, (by 2.5–4% per year in developing countries and by 2.3–3.5% in sub-Saharan Africa), improving livestock water productivity is imperative (Steinfeld 2002). In the Nile River Basin, the agricultural sector is responsible for 74.7% of water withdrawal. For example, for Egypt and Ethiopia this is estimated as up to 86% and in Sudan it is closer to 94% (Mason 2003). It is regularly reported that the water conflict in the Nile Basin is much related to allocation of water among the various countries. With a limited amount of river water and contrastingly increasing demand one can hypothesise that water shortage and as a result, tensions over water allocation will rise in the future (Mason 2003). This being the reality, efforts to improve water productivity must be increased. For example, preliminary water productivity estimation based on census data and considering only evapotranspiration water to produce animal feed and crops (crop-livestock mixed system in Ethiopia) suggested that crop and livestock water productivity values range between 0.1–0.5 US$ m À3 for LWP and 0.2–0.4 kg m À3 for CWP (A. Haileslassie, unpublished data). The international average for grain water productivity ranges between 0.1–2.45 kg m À3 . Clearly, the average water productivity for the Nile Basin is on the lower side of the scale and this indicates a potential for improvement (Cai and Rosegrant 2003). Ó Australian Rangeland Society 2009 10.1071/RJ09006 1036-9872/09/020213 CSIRO PUBLISHING www.publish.csiro.au/journals/trj The Rangeland Journal, 2009, 31, 213–222