The aim of this study was to identify the nature and quantify selectively soil chemical properties of the study area, to characterize and categorize salinity soil based on their salt content of the study area and to give suggestion appropriated reclaim of salt affected agricultural land management practices.
Soil salinity and alkalinity problems are commonly found in the arid and semi-arid regions of the earth due to insufficient annual rainfall to leach accumulated salts from the root zone. In other words, salt affected soils often occur in areas where soluble salts and sodium (Na) accumulate in soils through physical and chemical weathering of rocks or the pedogenic process of the soil development, atmospheric precipitation and fossil salts from marine or lacustrine environments. Moreover, heavy fertilizer application and use of poor-quality irrigation water and inadequate drainage have contributed to the development of salt affected soils and productivity deterioration of many soils in irrigated arid and semi-arid regions.
Ethiopia is the first in Africa and the ninth country in the World having more than 11 million ha of salt affected soils which are mainly found in the Rift Valley, Wabi Shebele River Basin and various lowlands of the country. Following the establishment of large-scale irrigated farms, the problem become worse due to poor drainage system and inappropriate water management practices coupled with unsound reclamation procedures,
To understand how improved soil fertility may assist in reaching these needs, it requires knowledge of salinity and sodicity related soil chemical properties the soils of the land’s agriculture. Such knowledge is believed to help the producers and production managers to understand about and make the necessary modifications in the soil-salt-water balance.
Table of Contents
1. INTRODUCTION
2. LITERATURE REVIEW
2.1. Definition to Describe Salt Affected Soils
2.1.1. Salt Affected soils in Ethiopia
2.1.1. Causes of Stalinization and Saline Soil
2.1.1. Saline soils
2.1. Classification of saline soil
2.1.2. Saline-Sodic Soils
2.1.3. Sodic soils
2.2. Causes of salt affected soils
2.2.1. Primary salinity
2.2.2. Secondary salinity
2.4. Impact of Salt Affected Soil on Plant
2.4.1. Osmotic effect of salt
2.4.2. Nutrition and ion toxicity of salt
2.4.3. Structure and permeability problem of salts in the soil
2.5. Adaptations of salt tolerant plants
2.6. Some salt tolerant plants
2.7. Other reclamation methods of salt affected soils
3. MATERIALS AND METHODS
3.1. Study area description
3.2. Method Of Sampling Collection and Preparation Sampling Units
3.2.2. Soil Extraction methods preparation.
3.3. Soil Sample laboratory analysis methods
3.3.1. Quantify The Soil pHe and Ece From Saturated Extraction.
3.3.2.Determination of soil Soluble Exchangeable base ( Na +2 , K+, Ca2+ and Mg +2).
3.3.2.1.Estimation of Soil Soluble Na + and K+ by using the flame photometer Instrument
3.3.2.2. Estimation of soil Ech. Ca2+ and Mg 2+ by using the AAS instrument
3.3.2.3. Estimation of Soil Sample SAR, ESP and ESR for Soil Sample for study site.
4. SOIL SAMPLE RESULT AND DISCUSSION
4.1. Characteristics of Chemical Properties of Soil Sample at Study Area
4.1.1. Soil pH and Electrical Conductivity Result interpretation and Discussion
4.1.2. Exchangeable Soluble cations result Interpretation and Discussion
4.1.3. Sodium adsorption ratio (SAR) and Exchangeable Sodium percentage (ESP)
5. CONCLUSIONS AND RECOMMENDATION
Research Objectives and Themes
The primary aim of this research is to characterize and classify the salt-affected soils in the agricultural farmlands of the Dire Dawa area. The study seeks to identify the nature of these soils, quantify their key chemical properties—including soluble salts, ECe, pH, and exchangeable cations—and provide evidence-based suggestions for appropriate management and reclamation practices to improve agricultural productivity and prevent further land degradation.
- Characterization of soil salinity levels based on standardized parameters.
- Quantification of soil chemical properties through laboratory analysis (e.g., AAS and flame photometry).
- Classification of soil types according to international salt-affected soil guidelines.
- Development of sustainable reclamation and land management strategies.
- Assessment of the impact of salinity on plant growth and nutrient availability.
Excerpt from the Book
2.4.1. Osmotic effect of salt
Water is absorbed into plants because of a gradient that exists between the soil solution and the cell sap of the interior root cells. High concentration of neutral salts in the soil solution tends to narrow the gap between the soils (external) and plant cell (internal) water potentials (BPMC 1996). This means that salts increase the energy with which water is held in the soil. Then the soil water potential become more negative, making water movement to the root cells more difficult. If the soil solution potential becomes negative enough, water may actually migrate out of the plant cells and into soil solution (Joe 2002; Silvertooth, & Norton 2000). There may be ample available soil moisture for plant growth; it is just that the plant cannot extract it because of the strong negative potential. The effect is essentially the same as drought. The plant cannot get enough water to maintain proper growth, or it takes so much plant energy extracting the water that growth suffers. The situation is exacerbated under water stress conditions or drought, particularly on fine-textured soils where it takes more pull for the plant to remove water at a given soil moisture level (Conway 2001; Gonzalez et al., 2004).
Summary of Chapters
1. INTRODUCTION: This chapter introduces the global and local challenge of soil salinity and alkalinity, highlighting the environmental factors and human-induced activities contributing to the degradation of productive land in Ethiopia.
2. LITERATURE REVIEW: This section covers the definitions and classifications of salt-affected soils, the underlying physical and chemical causes of salinization, their impacts on plant physiology, and established methods for their reclamation.
3. MATERIALS AND METHODS: This chapter details the study site location in Dire Dawa and provides a technical overview of the sampling procedures and laboratory analytical methods used to quantify chemical properties.
4. SOIL SAMPLE RESULT AND DISCUSSION: This section presents the laboratory findings for the soil samples, providing an interpretation of the chemical data in relation to soil salinity, alkalinity, and classification criteria.
5. CONCLUSIONS AND RECOMMENDATION: This final chapter synthesizes the study's findings, confirming the saline nature of the soil in the study area, and offers management recommendations to mitigate salt buildup and improve future land use.
Keywords
Salt affected soils, soil chemical analysis, Ece, SAR, ESP, Saline Soil, soil salinity, land degradation, agricultural management, soil reclamation, Dire Dawa, cation exchange capacity, flame photometry, atomic absorption spectrophotometer, ion toxicity.
Frequently Asked Questions
What is the primary focus of this study?
The study focuses on the characterization and classification of salt-affected agricultural soils in the Dire Dawa region of Ethiopia to better understand their chemical properties and improve management.
What are the main thematic areas covered?
The study addresses soil salinity definitions, causes of salinization, plant response to osmotic stress, laboratory methodologies for soil testing, and practical reclamation strategies.
What is the main research question or objective?
The objective is to characterize the nature of soil salinity in the Dire Dawa study site and provide scientific recommendations for reclamation practices based on laboratory soil tests.
Which scientific methods were employed for data collection?
The research used secondary data for site background and performed primary laboratory soil analysis using flame photometry and atomic absorption spectrophotometry to determine cation concentrations and soil salinity parameters.
What is covered in the main body of the work?
The work covers a literature review on salinity, a methodology section describing saturated paste extraction and chemical quantification, and a results section that interprets the specific soil parameters of the Dire Dawa samples.
Which keywords best characterize this research?
The research is best characterized by terms such as salt-affected soils, soil chemical analysis, Ece, SAR, ESP, and saline soil management.
How is "Saline Soil" specifically defined in this context?
Based on the study's guidelines, it is defined by electrical conductivity (ECe) > 4 dS/m, a SAR value < 13, and an ESP < 15, indicating lower sodium levels compared to calcium and magnesium.
What significance do the standard curves have in this research?
The standard curves are essential for accurately estimating the concentrations of Sodium (Na), Potassium (K), Calcium (Ca), and Magnesium (Mg) using instrumental measurements from flame photometry and AAS.
What is the conclusion regarding the Dire Dawa soil samples?
The study concludes that the soil samples from the study site are categorized as "Saline Soil" and that this condition currently does not severely affect the soil's physical properties due to relatively low sodium levels.
- Arbeit zitieren
- Soil Science Mintesinot Desalegn (Autor:in), 2019, Salt Affected Soils in Dire Dawa, Ethiopia. A Characterization and Classification, München, GRIN Verlag, https://www.hausarbeiten.de/document/938969
