SALINITY AND SOIL FERTILITY KIT - HANDBOOK
'Better approximately correct, in time and cost-effective`
than exactly wrong, too late and expensive`
Content
Preface
1 Introduction
2 Investigation of Water Samples for Irrigated Agriculture
2.1 Irrigation Water Samples
2.1.1 Sampling
2.1.2 General Evaluation of Water Samples
2.1.3 Direct Determinations in Water Samples
2.1.3.1 pH Determination
Procedure
Evaluation
2.1.3.2 Electrical Conductivity - EC
Procedure
Evaluation of EC in dS/m for Salinity
Evaluation of ECw with Respect to Soil Texture and Soil Salinity
Evaluation of ECw in dS/m for Water Infiltration
Calculation of TDS
Relationship EC / Ion-concentration
2.1.3.3 Sum of Alcaline Earth Cations
Procedure
Evaluation
2.1.3.4 Calcium
Procedure
Evaluation
2.1.3.5 Nitrate
Procedure
Evaluation
2.1.3.6 Chloride
Procedure
Evaluation
2.1.3.7 Hydrogencarbonate and RSC-Value
Procedure
Evaluation with respect to overhead sprinklin
Evaluation with respect to the RSC-value
Evaluation with respect to adjR-Na - value
Evaluation of general salinity effects (osmotic effects)
2.1.3.8 Sulfate Test
Procedure
Evaluation
2.1.4 Indirect Determinations in Water Samples
2.1.4.1 Sodium
Procedure
Evaluation
2.1.4.2 SAR-Value
Calculation Procedure
Evaluation
Graphical determination of the SAR-value after USDA, 1954
Classical evaluation of SAR in conjunction with the EC after USDA, 1954
SAR-evaluation with respect to infiltration problems (FAO, 1985)
Evaluation of SAR with respect to clay types
Evaluation of SAR after Wilcox
Evaluation of SAR with respect to irrigation technic
Evaluation of the SAR with respect to HCO3-: SARadj.
Evaluation with respect to the ratio HCO3-/Ca: adjR-Na - value
Comparison of SAR and adjR-Na for an example from Rajasthan/India
2.1.4.3 ESP-Value
Calculation Procedure
Evaluation
2.1.4.4 Magnesium
Determination
Evaluation of Salinity Effect
2.1.4.5 SAR-Mg-adj
Determination
Evaluation
2.1.4.6 Calculation of Sulfate Concentration
Procedure
Evaluation with respect to crop growth
Evaluation with respect to concrete
Quality Check
2.1.4.7 Gypsum-Forming Ions
Calculation Procedure
Evaluation
2.1.4.8 Osmotically Effective EC: ECeff
Calculation Procedure
Evaluation
2.1.4.9 Proposed Form for Irrigation Water Quality Evaluation
2.2 Salinity of Ground- and Drainage Water
2.2.1 Sampling
2.2.2 Measurements
2.2.3 Salt Balance for Salinity Management
2.2.3.1 Classical Salt Balance
2.2.3.2 Salt Balance Affected by Rainfalls
2.2.3.3 Salt Balance Affected by Groundwater Salinity
2.2.3.4 Salt Balance Affected by Formation of Soluble Salts from Soil
Reactions (Lac Horo/Mali)
2.2.3.5 Salt Balance Affected by Fertilizers
2.2.4 Leaching Requirement/LR: Irrigation Water for Soil Salinity Control
2.2.4.1 LR Calculated from the Irrigation and Drainage Water Salinity
2.2.4.2 LR Calculated from the Irrigation Water Salinity and Tolerated
Soil Salinity
3 Investigation of Soil Samples with Respect to Agriculture and Environment
3.1 Introductory Remarks
3.1.1 Need for Quantitative Evaluations of Salt-Affected Soils
3.1.2 General Recommendations for Practical Use
3.2 Site Description and Sampling
3.2.1 Site Description
3.2.2 Recommendations for Sampling
3.3 Description of the Soil Sample
3.3.1 Colour of the Sample
3.3.2 Humidity of the Sample
3.3.2 Texture of the Sample
3.4 EC-Measurements on the Sample - General Salinity
3.4.1 Classical Procedure Determining the ECse of the Soil Saturation Extract
Procedure
Procedure/steps
Evaluation
3.4.2 Determination of the EC under Field Conditions
3.4.3 Pre-Testing of Soil Salinity in the Water Saturated Paste: ECsp
Procedure
Evaluation
3.4.4 Water Addition to 1/1-Extract and EC-1/1
Procedure
Evaluation
3.4.5 Water Addition to 1/2-Extract and EC1/2
Procedure
Evaluation
3.5 Direct Measurements in the EC1/2 Extract
3.5.1 pH-H2O
Procedure
Evaluation
Evaluation of base saturation from pH-H2O
3.5.2 Nitrate
Procedure
Evaluation
3.5.3 Water-Soluble Sum of Ca+Mg
Procedure
Test Strips
Titration
Evaluation
3.5.4 Water-Soluble Ca
Procedure
Test Strips
Titration
Evaluation
3.5.5 Water-Soluble Chloride
Procedure
Test Strips
Titration
Evaluation
3.5.6 Water-Soluble Hydrogen-Carbonate
Procedure
Test Strips
Titration
Evaluation
3.5.7 Sulfate Test
Procedure
Evaluation
3.6 Indirect Determinations and Calculations
3.6.1 Sodium
Procedure
Evaluation
3.6.2 Magnesium
Procedure
Evaluation
3.6.3 Sodium Diagram after Wilcox
3.6.4 Exchangeble Sodium Percentage ESP
Calculation Procedure
Graphical Procedure
Evaluation in general
Evaluation with respect to specific Mg-effects
3.6.5 Calculated Sulfate
Procedure
Evaluation
3.6.6 Salinity of Soil Solutions under Field Conditions
Principle Calculation Procedure
Application for Loamy Soils
Application for Sand
Application for Loamy Sand
3.6.7 Relationship Electrical Conductivity/Osmotic Potential of Soil Solutions
Calculation Procedure
Division of Crops/Plants According to Salt Tolerance
3.6.8 Additivity of Soil Matric and Osmotic Water Potential with Respect to
Water Supply of Plants
3.6.8.1 Soil Matric Effect on Plant Water Supply
3.6.8.2 Soil Osmotic Effects on Plant Water Supply
3.6.8.3 Conclusions for Summing Up Soil Osmotic and Matric Effects on
Plant Water Supply
3.6.9 Salt Leaching for Soil Reclamation
3.6.9.1 Estimating the Need of Water for Pre-Leaching by Rule of Thumb
3.6.9.2 Calculation Procedure for Pre-Leaching
3.6.9.3 Estimation of Water Need after Russian Experience
3.6.9.4 Soil Amelioration through Surface Desalinization
3.6.10 Proposed Form on Soil Salinity
3.6.11 Basics for an Applied Research Concept on Saline Irrigation and
Crop Salt Tolerance
3.6.11.1 Principle Aspects of the Research Concept
3.6.11.2 The Rhizocylinder in Relation to the Salt Tolerance of Irrigated Crops
3.7 Additional Soil Fertility Parameters
3.7.1 pH-KCl
Procedure
Evaluation
3.7.2 Cation Exchange Capacity - CEC
3.7.2.1 Estimation of CEC from Soil Texture
3.7.2.2 Measuring of CEC
Procedure
Evaluation of Ca+Mg
3.7.3 Ca-Deficiency to Plants
Procedure
Evaluation of Ca
3.7.4 Exchangeable Ca/Mg-ratio
Procedure
Evaluation of Ca/Mg-ratio
3.7.5 luminium Toxicity at Low Soil-pH
Procedure
Evaluation
3.7.6 Presence of Soil Gypsum
3.7.6.1 Testing for the Presence of Gypsum
Procedure
3.7.6.2 Determination of Gypsum Content
Procedure
Evaluation
3.7.7 Soil Carbonate
3.7.7.1 Pretest for Soil Carbonate Content
Procedure
Evaluation
3.7.7.2 Determination of Carbonate Content
Procedure
Evaluation
3.7.8 Organic Matter Content - OM
3.7.8.1 Estimation of OM-Content
Evaluation
3.7.8.2 Verification of OM-Content
Procedure
3.7.9 Plant-Available Soil-Phosphate
Procedure Acetic Acid Extraction
Procedure HCl - Extraction
Evaluation
3.7.10 Plant-Available Potassium/K
Procedure
Evaluation
3.7.11 Proposed Form on Soil Fertility Parameters
4 Investigations on Field Fresh Plant Samples
4.1 Evaluation of Nutrient Deficiencies after Leaf Symptoms
4.2 Theoretical Considerations and Experience with plant sap analysis
4.3 Collection of Some Data from Various Countries
4.3.1 Nitrate in Plant Saps
4.3.2 Phosphate in Plant Saps
4.3.3 Potassium (K) in Plant Saps
4.4 Measurement Procedures
4.4.1 General Recommendations for Sampling
4.4.2 Preparation for Plant Sap Analysis
4.4.3 Measurements on Cut Surfaces of Stems and Leaf Petioles
4.4.3.1 Evaluation of Nitrate/NO3
4.4.3.2 Evaluation of Phosphate/PO4
4.4.3.3 Evaluation of Potassium/K
5 Annexes
5.1 List of Literature, Tables and Graphs
5.1.1 List of Literature
5.1.2 List of Tables
5.1.3 List of Tables, cont
5.1.4 List of Figures
5.2 List of Abbreveations
5.3 Chemistry
5.4 List of Some Basic Soil Data
5.5 Chemistry
5.6 List of Crop Salt-Tolerance Data