The main aim of the study was to apply a stochastic frontier production function on the farm level data collected from maize farmers under the Olushandja Dam and Etunda Irrigation Schemes in North-central Namibia, to evaluate if the productivity of irrigation maize can be technically improved. The results from the stochastic frontier analysis indicated that the technical efficiency of the farmers under the two irrigation schemes is low, ranging from 0.043 to 0.999 with an average of 0.434, implying that there is 56.7% potential for maize farmers, to increase their production efficiency with the same technologies. The results also show that productivity gains as the size of land increases. This probably means that, those farmers with small plots, applied too much of inputs with respect to the size of their land. For instance farmers are using both inorganic fertilizers and urea on the same and this might result in an overuse of inputs and thus diminishing returns. Using inorganic fertilizer on the same plot year after year might result in the soil fertility being negatively affected by too much application of fertilizers. Moreover, those farmers with access to credit facilities, contact with extension services, those trained on good horticultural practices and those who are employed somewhere are more technically efficient in maize production. The study recommends that smallholder maize farmers should be trained in good agricultural practices.

Keywords: Technical efficiency, stochastic frontier, irrigation, small scale farmers, Namibia.