Document Type

Dissertation - Open Access

Award Date

2022

Degree Name

Doctor of Philosophy (PhD)

Department / School

Agronomy, Horticulture, and Plant Science

First Advisor

David Clay

Keywords

saline-sodic soils, salt-affected soils soil management, soil salinity, soil sodicity

Abstract

Soil salinity and sodicity are issues of growing concern in the United States (U.S.) and globally. Knowledge gaps for glaciated, dryland salt-affected soils exist because much original salinity and sodicity research focused on irrigated systems. Land managers are being asked to produce food, feed, fiber, and fuel for an expanding global population. The number of land managers and crop advisors who are affected by these soils is increasing. Addressing salinity and sodicity knowledge gaps will be critical for their success. Salinity and sodicity have been impeding crop productivity since the advent of cultivation. Saline and sodic soils form via multiple natural and human-induced pathways. Parent materials that are inherently high in ion (salt) concentrations can, through dissolution of mineral materials, release ions to the soil-water solution. As rainfall patterns in certain regions, namely the North America Northern Great Plains (NGP), trend toward higher seasonal rainfall, water tables rise. Ions are then transported upward with the water table and then to the soil surface via capillary rise. This mechanism of salt accumulation is unique compared to irrigated systems where salts accumulate at the soil surface from applications of irrigation water that has a high electrical conductivity (EC). Fundamental differences between salt-accumulation in nonglaciated, irrigated systems and glaciated, dryland systems insinuate that management recommendations from irrigation-based systems may not be pertinent or applicable to the NGP. For this reason, there is great need for a comprehensive textbook on salinity and sodicity that encompasses the management challenges faced by land managers and crop advisors in all geographies. Additionally, further research in the NGP is needed to investigate potential salinity and sodicity reclamation strategies that are effective and that can realistically be implemented on working farms. Throughout this document, Chapter 1 addresses knowledge gaps in more detail. Chapter 2 discusses saline and sodic soil development across multiple geographies, how saline and sodic soils are measured and defined, and the classification system used in the U.S. for these soils. Chapter 3 discusses research findings and the effect of chemical amendments in combination with phytoremediation on soil health in NGP saline-sodic soils. Chapter 4 serves as a summary of the knowledge gaps, of key issues as identified by the research discussed herein, and of areas of future work to address the growing issue of saline and sodic soils.

Library of Congress Subject Headings

Sodic soils -- Great Plains.
Soils, Salts in -- Great Plains.
Soil management -- Great Plains.
Soils -- Great Plains -- Classification.
Soil remediation -- Great Plains.

Number of Pages

101

Publisher

South Dakota State University

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Rights Statement

In Copyright