Soil Genesis in a Natrargid‐Haplargid Complex in Northern Montana

Abstract

Classical theory of the genesis of Natargids (solonetz) involves the upward movement of sodium from a water table. Examination of 24 pedons representing four Soil Series developed in glacial till on the Northern Great Plains (Montana) suggests that Natrargids (solonetz and solodized‐solonetz) and Haplargids (soloth) can develop in the absence of a water table. The four soils occur as a complex on “panspot” rangeland with the soloth and solodized‐solonetz on microknolls and the solonetz in microdepressions. The panspot soils have significantly (p = 0.01) greater B horizon clay contents than associated non‐panspot soils. X‐ray diffraction analyses indicate decomposition of smectite inherited from the parent material in the sola of all soils. Solonization of the panspots is driven by reduced infiltration and subsurface water movement in response to matric and osmotic potential gradients. Panspots occur over high points in the till‐shale boundary where the wetting front penetrates into the salty, calcareous till. Movement of sodium upwards from the shale contact results in dispersion of the panspot B horizon. Natric horizon development causes reduced infiltration and subsurface interpedon translocation of water, salts, and amorphous materials.

Pedogenesis, land management and soil classification in hyper‐arid environments: results and implications from a case study in the United Arab Emirates

“…Also termed alkalization, this occurs when soils subject to salinization are drained (Munn & Boehm, ). The excess soluble salts are leached out, the colloids because of the influence of Na become dispersed, and a strongly alkaline reaction develops.…”

Factors Controlling Distribution of Selenium by Geomorphic and Pedologic Processes in a Semi-Arid Environment, Laramie Basin, Wyoming

“…Pedon G may have been affected by the ditch as well, even though it is 50 m below it Pedons F and Gwererelatively shallow to the 2Cr'horizon contact (<160 cm). The relatively shallow soil depth may explain the occurance of high SAR values in pedons F and G at shallower depths than in other profiles where the 2Cr horizons occured at depths of> 200 cm (Munn and Boehm, 1983).…”

Origin of Smectite in Salinized Soil of Junggar Basin in Xinjiang of China

“…For example, smectite in salt-affected soils in North America would experience degradation due to the impact of high salt and soda content [10]. Smectite deformed in the surface horizons of solonetzic soils in Montana [11]. In these existing studies, the impact of high salinity on the formation of smectite was reported, whereas it was not reported anywhere on how the different salt content would influence the formation of smectite.…”