Salt-affected soils in Tanzanian agricultural lands: Type of soils and extent of the problem

Abstract

ABSTRACTSalt-affected soils are a global challenge, affecting 1 billion ha of land, with 200 million ha found in Africa. The challenge brings adverse impacts on agricultural productivity, food security, environmental sustainability, and food security. In Tanzania, more than 2 million ha of land are salt-affected, of which 1.7 million ha are saline soil and 0.3 million ha are sodic soil. To cope with this threat, it is necessary to have a thorough understanding of its extent (coverage), existing types, and available management strategies. This review presents a comprehensive account of the challenges and opportunities of salt-affected soils in Tanzania and examines management options that have been observed to increase agricultural productivity in rice-growing areas. A systematic review of relevant articles published in databases was carried out using PRISMA guidelines and flowcharts. This review highlights the origin, extent, types, and various techniques for alleviating salt-affected soil problems. It also emphasize on the use of inorganic and organic amendments, salt-tolerant varieties, irrigation water quality, and drainage infrastructure. We revealed that farmers, use burned and unburned rice husks, sawdust, gypsum, and farm yard manure (FYM) as copping mechanisms. Furthermore, there have been continuing efforts to develop salt-tolerant rice varieties, coupled with maintenance of irrigation infrastructure and site-specific soil management options, as appropriate solutions to tackle salt issues. Given the light of existing data, the review recommends using RS and GIS for updating information on salt-affected soils, particularly in irrigated areas, as an essential component of sustainable management and preventing further loss of agricultural land.

Keywords

• climate change
• economic implication
• inorganic amendments
• organic amendments
• salt tolerance
• reclamation