摘要 : The objective of this paper is to evaluate why small-scale farmers do not persist with irrigation along the Senegal River Valley of Mauritania. Surveys of all households of 12 villages that combine traditional agriculture with irr... 展开 The objective of this paper is to evaluate why small-scale farmers do not persist with irrigation along the Senegal River Valley of Mauritania. Surveys of all households of 12 villages that combine traditional agriculture with irrigated rice production collected information on workload, inputs and productivity of cropping systems together with food requirement and costs in local markets. Analyses revealed that, at the scale of farming attempted, there is no shortage of labor within most households when irrigated rice is combined with traditional rain fall cropping in the wet season and flood-recession crops in the cold, dry season. There is, however, a major limitation to successful combination in the generally negative return of rice production to labor and inputs. While input costs for traditional systems are very small, real costs of rice production (4000 kg paddy/ha) exceed returns in most cases. Farmers only persist with irrigation for as long as the infrastructure functions with minimum maintenance. This explains the observed gradual abandonment of many irrigation schemes unless additional investment is available to repay initial loans and renew infrastructure. While operational, the schemes do add significantly to food security in the villages and offer paid labor to landless residents. Greater yields of rice, greater irrigation water-use efficiency through improved irrigation management, crops that demand less water and more intensive use of irrigated land are options to increase return to inputs. Success here would remove the food contribution from traditional agriculture currently required to sustain irrigated rice production, and establish a continuing and profitable contribution from irrigated agriculture.Digital Object Identifier http://dx.doi.org/10.1016/j.agsy.2012.04.002 收起