Improvemet of a Solonetzic (Slick Spot) Soil by Deep Plowing, Subsoiling, and Amendments

Abstract

AbstractSoil improvement studies, including deep lowing, subsoiling and gypsum treatments, were conducted on an irrigated solonetzic soil association in southeastern Oregon. The unproductive saline‐sodic (solonetz‐like) soil tentatively classified as Malheur silt loam (with slick spots) and described as a Nadurargid, occurs in complexes with normally leached soils of the Nyssa and related soil series. The saline‐sodic soils were chemically reclaimed in 3 to 4 years by deep plowing 90‐cm deep without gypsum and by deep plowing with gypsum at rates of 18 metric tons/ha (8 tons/acre) and 36 metric tons/ha (16 tons/acre). Crop yields, water intake rates, and water and root penetration were greatly increased by deep plowing. The soils were moderately improved by 36 metric tons/ha of gypsum alone and by subsoiling with gypsum. Subsoiling without gypsum was not beneficial. The results over a 4‐year period indicate that the salt‐affected soils were effectively and most economically reclaimed by deep plowing without gypsum. Deep plowing also improved the productivity and physical conditions of the non‐saline associated soils.