Conceptual and Practical Framework to Address Gypsum Management in Salt-Affected Soils

This chapter gives theoretical and practical information for proper gypsum management in salt-affected soils. Although gypsum is well known as amendment an to ameliorate soil physical conditions, key factors should be carefully considered to optimize gypsum agronomic efficiency and effectiveness at farm level. Some of the main factors are the gypsum quality for agriculture use and physiographical and soil features related with salinity and sodicity constraints. Under typically non-irrigated sodic-soils, where cattle production is the most frequent land use, surface cover and water table dynamics play a significant role in defining the gypsum technological management. This is valid, particularly, in terms of application methods. In high-yielding crops receiving supplementary irrigation with poor quality water, gypsum management is quite different. Some of the key differences arise from surface sodification while subsoil sodicity is not a constraint in these agricultural soils. However, other issues like surface compaction and exchangeable sodium percentage (ESP) are relevant diagnosis factors to address gypsum management in irrigated land. Moreover, combined application of gypsum and organic amendments like animal manure are considered effective technologies to improve the physical quality of salt-affected soils alongside prevention practices.