A comparative, retrospective cross-sectional study was conducted to investigate the role of irrigation on improvement of nutritional status of children aged 6 - 59 months in a semi-arid setting. Two equal samples of fifty-nine children (aged 6 - 59 months) hereafter, referred to as the Project and the Non-project groups, respectively were randomly selected from households with and without access to irrigation water in Kieni East Division of Nyeri District, Kenya. The study area is situated in the drier western leeward side of Mt. Kenya and is characteristic by unreliable rainfall of between 500 to 1200 mm per annum.

Weight, height and age of index children were determined and the corresponding standard deviations of weight-for-age, weight-for-height and height-for-age calculated and compared to the reference standards developed by the US National Centre for Health Statistics. Energy and nutrient intake was determined using 24-hour dietary recall method. The findings on socio-demographic characteristics showed that the Project and Non-project households were similar in terms of household size, land size, marital status of the respondent, maternal and paternal education and occupation. The calorie intake of over two-fifth (42%) of the children from the Non-project households compared to 39% from the Project households was below the Recommended Daily Allowance.

The children from commercial farming Project households had significantly higher weight-for-age Z-score than those from commercial farming Non-project households. Similarly, children from high-income Project households had significantly higher height-for-age Z-score than those from high-income Non-project households. The prevalence of stunting was also significantly lower in the high-income Project households compared to high-income Non-project households. Among the male children, the prevalence of underweight was significantly higher in Non-project households than in Project households. Overall, the prevalence of stunting and underweight which are indicators of long-term nutritional deprivation were higher in Non-project households than Project households. The findings of the study led to the conclusion that irrigation contributes to increased per capita food availability resulting in higher energy intakes and subsequently enables households to safeguard young children against chronic malnutrition. Also, poverty as characterised by low household income remains a main determinant of nutritional status.