Five soil profiles from a saline zone in the province of Seville CMarismas del Guadalquivir", SW. Spain) and one from an adjacent non-saline zone, have been analyzed in order to determine their physical and chemical properties and their classification. All of these soils are recent and of fine texture. Hydraulic conductivity, except in top layers, as well as aeration porosity, is always low; non-available water holding capacity and linear extensibility, high. Differences are however found between those located near the river channel and those at the limit of Marismas in contact with vertisols, due to parent material, situation and use. Particularly noticeable is the progressive increment of their vertic character.

Five soil profiles from a saline zone in the province of Seville CMarismas del Guadalquivir", SW. Spain) and one from an adjacent non-saline zone, have been analyzed in order to determine their physical and chemical properties and their classification. All of these soils are recent and of fine texture. Hydraulic conductivity, except in top layers, as well as aeration porosity, is always low; non-available water holding capacity and linear extensibility, high. Differences are however found between those located near the river channel and those at the limit of Marismas in contact with vertisols, due to parent material, situation and use. Particularly noticeable is the progressive increment of their vertic character.

In Sevilla Province, s6utbwestern Spain, bencbmark soils of eigbt agricultural areas were defined using traditional soil ped6n c6ncepts of S6i1 survey. The characterizati6n emphasized morpb6logical, chemical, and physical analyses. These eigbt representative S6i1S were cIassified as f6116WS: R6jO Aljarafe (Typic Rbod6xeralO, Tierraneara Camp6 (Typic PeIl6xerert), Salin6 Marismas (Vertic Fluvaquent), Franc6 Vega (Typic Xerofluvent), Arena Terrazas (Aquic HaploxeralO, Almagra Alc6res (Calcic Hapl6xeralO, Bujeo Campiña (Typic Chr6m6xerert), and Albariza Estepa (Entic Hapl6xer-611). By application of a computer-based soil evaluation system developed with inf6rmati6n from a representative zone, predlcted yIelds were calculated f6r wheat (Triticum IIntirum L.), field coro (Zu lIUIys L.), and coUon (Gossypium IIinutum L.) for tbe selected bencbmark soils. Productivity inf6rmation was transferred from the representative mne t6 tbe eight agricultural areas within Sevilla Provinee. Soils were ranked in tbe f6I16wing 6rder acoording t6 predicted yields f6r the tbree crops: Bujeo Campiña > Tierranegra Campo > Franco Vega> Salin6 Marismas> R6jO Aljarafe> Almagra AIcores > Albariza Estepa > Arena Terrazas.