Kiwale, Antery Antony2026-03-122026-03-121999https://www.suaire.sua.ac.tz/handle/20.500.14820/7400DissertationIn Tanzania the problem of salinity and sodicity is common and widespread especially in irrigation schemes, the Tanganyika Planting Company Ltd in Arusha Chini- Moshi (TPC) being one of them. A detailed study was carried out to investigate the distribution, origin and characteristics of salt affected soils in TPC. The objectives were to categorize the soils in terms of the salinity problem; to investigate the sources of salt accumulation and asses the quality of irrigation and underground waters in the study area. A preliminary survey of the irrigated fields was done and experimental fields were selected on the basis of the available information, crop growth performance and visual appearance of soil and plants. Soil characterization was based on physical and chemical properties. Detailed laboratory characterization was done on the salt affected soils, irrigation and underground waters. A soil morphology study revealed that the soils are young profiles, of deep alluvial deposits. The soils were classified according to the FAO (1988) soil classification system and found to be Humic Cambisols; Eutric Gleysols and Calcaric Fluvisols in South, North and West areas of TPC respectively.iii The main categories of soils in TPC were observed to be generally: Normal soils in north and west areas; Saline (fields 19A and 2Id) and sodic (80%) soils in South area; Saline sodic soils in field R8 in West area. Kikuletwa river water showed a potential to cause soil salinity with electric conductivity values of 0.95 and 0.48 dS/m in first and second water sampling respectively. Ruvu and Weruweru waters were found to have medium and low salinity levels, values being 0.35,0.16 and 0.07,0. IdS/m respectively. As far as sodium content of water is concerned, all the three rivers were found to have low sodium. Values are 19.71, 11.9 and 3.33mg/kg in Kikuletwa, Ruvu and Weruweru rivers respectively. Other causes of salts in TPC soils were found to be seepage from Kikuletwa river, higenIrrigation schemesSalinity problemSoils distributionTanzaniaThesis