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
2.1.3.2 Electrical Conductivity - EC
2.1.3.3 Sum of Alcaline Earth Cations
2.1.3.4 Calcium
2.1.3.5 Nitrate
2.1.3.6 Chloride
2.1.3.7 Hydrogencarbonate and RSC-Value
2.1.3.8 Sulfate Test
2.1.4 Indirect Determinations in Water Samples
2.1.4.1 Sodium
2.1.4.2 SAR-Value
2.1.4.3 ESP-Value
2.1.4.4 Magnesium
2.1.4.5 SAR-Mg-adj
2.1.4.6 Calculation of Sulfate Concentration
2.1.4.7 Gypsum-Forming Ions
2.1.4.8 Osmotically Effective EC: ECeff
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
3.4.2 Determination of the EC under Field Conditions
3.4.3 Pre-Testing of Soil Salinity in the Water Saturated Paste: ECsp
3.4.4 Water Addition to 1/1-Extract and EC-1/1
3.4.5 Water Addition to 1/2-Extract and EC1/2
3.5 Direct Measurements in the EC1/2 Extract
3.5.1 pH-H2O
3.5.2 Nitrate
3.5.3 Water-Soluble Sum of Ca+Mg
3.5.4 Water-Soluble Ca
3.5.5 Water-Soluble Chloride
3.5.6 Water-Soluble Hydrogen-Carbonate
3.5.7 Sulfate Test
3.6 Indirect Determinations and Calculations
3.6.1 Sodium
3.6.2 Magnesium
3.6.3 Sodium Diagram after Wilcox
3.6.4 Exchangeble Sodium Percentage ESP
3.6.5 Calculated Sulfate
3.6.6 Salinity of Soil Solutions under Field Conditions
3.6.7 Relationship Electrical Conductivity/Osmotic Potential of Soil Solutions
3.6.8 Comment on the Additivity of Soil Osmotic and Soil Matric Water
Potential
3.6.8.1 Soil Osmotic Effects on Root Water Uptake
3.6.8.2 Soil Matric Effects on Root Water Uptake
3.6.8.3 Conclusion for Summing up the Effects of Soil Water Potentials
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
3.7 Additional Soil Fertility Parameters
3.7.1 pH-KCl
3.7.2 Cation Exchange Capacity - CEC
3.7.2.1 Estimation of CEC from Soil Texture
3.7.2.2 Measuring of CEC
3.7.3 Ca-Deficiency to Plants
3.7.4 Exchangeable Ca/Mg-ratio
3.7.5 luminium Toxicity at Low Soil-pH
3.7.6 Presence of Soil Gypsum
3.7.6.1 Testing for the Presence of Gypsum
3.7.6.2 Determination of Gypsum Content
3.7.7 Soil Carbonate
3.7.7.1 Pretest for Soil Carbonate Content
3.7.7.2 Determination of Carbonate Content
3.7.8 Organic Matter Content - OM
3.7.8.1 Estimation of OM-Content
3.7.8.2 Verification of OM-Content
3.7.9 Plant-Available Soil-Phosphate
3.7.10 Plant-Available Potassium/K
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 Table of Chemical Symbols
6 Abbreveations
7 Literature
8 Annexes