The extent and effects of salinity and alkalinity in community base irrigation schemes in the dryland areas of Tanzania. Case study: Chali and Bahi irrigation schemes in Dodoma region

Abstract

Irrigation activities in the drylands of Tanzania are increasing, this may lead to serious problems of salinity and alkalinity in the irrigation schemes. This paper attempts to determine the extent of salinity and alkalinity problems in Bahi and Chali irrigation schemes. The soil data indicates that Bahi scheme has sodicity problems with the ESP values ranging from a minimum of 25.07% to 45.37% while the EC values range from 0.25mS/cm to a maximum of 1.36mS/CM. Chali scheme has both sodicity and salinity problems with ESP values ranging from 3.92% to 52.65% and 30% of the samples had EC values, ranging from 4-16mS/cm. One of the physical effects in the schemes due to sodicity is the formation of hard crusts on the topsoils. Based on literature review salinity and alkalinity have minimum effects on rice production at Bahi scheme, but may have significant effects on rice production at Chali scheme.

Journal of Building and Land Development Vol. 13 (2) 2006: pp. 41-48