Chapter 1. Origin and nature of saline and alkali soils.
Sourcels of so uble salts.
Salinization of s-oils.
Alkalication or accumulation of exchangeable sodium in soils
Characteristics of saline and alkali soils,
Chapter 2. Determination of the properties of saline and alkali soils
Estimation of soluble salts from electrical conduc-tivity
Conductivity of the saturation extract and the saturation percentage
Relation of conductivity to salt content and osmotic pressure
Conductivity of 1:1 and 1:5 extracts
Salinity appraisal from the electrical resistance of soil paste
Conversion of conductivity data to a standard ref- erence temperature
Comparison of percent salt in soil and extract measurements
Soluble cations and anions
Alkaline-earth carbonates (lime)
Permeability and hydraulic conductivity
Moisture retention by soil
Density and porosity
Aggregation and stability of structure
Choice of determinations and interpretation of data.
Equilibrium relations between soluble and ex- changeable cations.
Chemical analyses of representative soil samples.
Cross-checking chemical analyses for consistency and reliability
Factors that modify the effect of exchangeable sodiumonsods
Surface area and type of clay mineral
Potassium status and soluble silicate
Sequence of determinations for soil diagnosis
Chapter 3. Improvement and management of soils in
Arid and semiarid regions in relation to salinity and alkali
Irrigation and leaching in relation I0 salinity control.
Field leaching trials
Special practices for salinity control
Chapter 3-Continued Drainage of irrigated lands in relation to salinity control
Water-transmission properties of soils.
Layout and placement of drains
Techniques for drainage investigations
Measurements of hydraulic head
Determination of subsoil stratigraphy.
Determination of water-transmitting properties of soils
Chemical amendments for replacement of exchange- able sodium
Suitability of various amendments under different soil conditions
Chemical reactions of various amendments in alkali soils
Class 1. Soils containing alkaline-earth car- bonates
Class 2. Soils containing no alkaline-earth car- bonates; pH 7.5 or Higher
Class 3. Soils containing no alkaline-earth car- bonates; pH less than 7.5
Estimation of amounts of various amendments needed for exchangeable-sodium replacement.
Speed of reaction of amendments and economic - considerations
Application of amendments
Laboratory and greenhouse tests as aids to diagnosis.
Reclamation tests in the ﬁeld
Reclamation of saline and alkali soilsin humid regions.
Chapter 4. Plant response and crop selection for saline and alkali soils
Signiﬁcance of indicator plants for saline soils
Crop response on saline soils
Salinity and water availability
Specific ion effects
Crop selection for saline soils
Relative salt tolerance of crop plants
Relative boron tolerance of crop plants
Chapter 5. Quality of irrigation water
Methods of analzsis
Characteristics t at determine quality
Classification of Irrigation waters,
Diagram for classifying irrigation waters.
Effect of boron concentration on quality
Effect of bicarbonate ion concentration on quality.
Chapter 6. Methods for soil characterization
Samping soil extracts, and salinity appraisal
(1) soil sample collecting, handling, and sub- sampling
(2) Saturated soil paste
(3) Soil-water extracts
(3a) Saturation extract
(3b) Twice-saturation extract for coarse-tex- tured soils (tentative)
(3c) Soil-water extracts at 1:1 and 1:5
(3d) Soil extract in the ﬁeld-moisture range
(4) Electrical conductivity of solutions
(4a) Standard Wheatstone bridge
(4b) Direct indicating bridge
(5) Resistance of soil paste and percent salt in soil
(6) Freezing-point depression
(6a) Freezing-point depression of solutions
(6b) Freezing-point depression of water in soil cores Soluble cations and anions
(7) Calcium and magnesium by titration with ethylenediaminetetraacetate (Versenate)
(8) Calcium by precipitation as calcium oxalate.
(9) Magnesium by precipitation as magnesium ammonium phosphate
(10a) Sodium by ﬂame photometer
(10b)) Sodium by precipitation as sodium uranyl zinc acetate
(lla) Potassium by ﬂame photometer
(llb) potassium by precipitation as potassium dipicrylaminate
(12) Carbonate and bicarbonate by titration with acid
(13) Chloride by titration with silver nitrate
(14a) Sulfate by precipitation as barium sul- fate
(14b) Sulfate by precipitation as calcium sul- fate
(15) Nitrate by phenoldisulfonic acid
(16) Silicate as silicomolybdate
(17) Boron Exchangeable cations
(18) Exchangeable cations
(20) Exchancgeable-cation percentages
(20a) Exchancgeable-cation percentages by di rect etermination
(20b) Estimation of exchangeable-sodium-per centage and exchangeble- potassium-percentage from soluble cations Suglplementary measurements
(21) pH determinations
(21a) pH reading of saturated soil paste
(21b) pH reading of soil suspension
(2lc) PH reading of waters, solutions, and soil extracts
(22a) G sum by precipitation with acetone (quantitative)
(22b) Gypsum by precipitation with acetone (quantitative).
(22c) Gypsum by increase in soluble calcium plus magnesium content upon dilution.
(22d) Gypsum requirement
(23) Alkaline-earth carbonates (lime)
(23a) Alkaline-earth carbonates by effervescence with acid
(23b) Alkaline-earth carbonates by gravimelric loss of carbon dioxide
(23c) Alkaline-earth carbonates from acid neu- tralization
(24) Organic matter.
(25) Total and external ethylene glycol retention.
(26) Soil-moisture content
(27) Saturation percentage
(27a) Saturation percentage from oven-drying.
(27b) Saturation percentage from volume of water added
(27c) Saturation percentage from the weight of a known volume of paste.
(28) Inﬁltration rate
(29) 1/10-atmospnre percentage
(30) l/3-atmospnere percentage
(31) 15-atmospnere percentage
(32) Moisture-retention curve
(33) Field-moisture range
(34) Hydraulic conductivity
(34a) Hydraulic conductivity of soil cures-
(34b) Hydraulic conductivity of disturbed soil.
(34c) Hydraulic conductivity from piezometer measurements
(34d) Hydraulic conductivity from auger-hole measurements
(35) Hydraulic-head measurements in saturated soil
(35a) Piesometers installed by driving
(35b) Piezometers installed by jetting
(35c) Observation wells uncased or with per- forated casing
(36) Ground-water graphical methods
(36a) Water-table contour maps
(36b) Water-table isobath maps
(36c) Proﬁle ﬂow patterns for ground water
(36d) Water-table isogleths for showing time variations in t e elevation of the water table Physical measurements
(37) Intrinsic permeability
(37a) Permeability of soil to air
(37b) Permeability of soil to water
(38) Bulk density
(39) Particle density
(41) Particle-size distribution
(42) Aggregate-size distribution
(42a) Wet sieving
(42b) Aggregation of particles less than so microns
(43) M Gulus of rupture
Chapter 7. Methods of plant culture and plant analysis Plant-culture techniques adapted to salt-tolerance investigations
(50) Artificially salinized ﬁeld plots
(51) Drum cultures
(52) Sand and water cultures Methods of plant analysis
(53) Sampling and preparation of plant samples. .
(54a) Wet digestion
(54b) Magnesium nitrate ignition
(55a) Calcium by ﬂame photometer
(55b) Calcium by oxalate method
(57a) Sodium by ﬂame photometer
(57b) Sodium by uranyl zinc acetate
(58a) Potassium by ﬂame photometer
(58b) Potassium by cobaltinitrite
Chapter 8. Methods of analysis of irrigation waters.
(70) Collection of irrigation water samples
(71) Records, reports, and expression of results.
(72) Electrical conductivity
(73a) Boron, electrometric titration
(73b) Boron, colorimetric, using carmine
(74) Dissolved solids
(75) pH of waters
(76 ) Silica
(76a) Silica, gravimetric.
(76b) Silica, colorimetric
(79) Calcium and magnesium by the Versenate method
(80) Sodium. .
(80a) Sodium by uranyl zinc acetate, gravi- metric
(80b)) Sodium by ﬂame photometer
(81a)‘Potassium by cohaltinitrite, gravimetric.
(81b)) Potassium by cobaltinitrite, volumetric.
(81c) Potassium by ﬂame photometer
(82) Carbonate and bicarbonate
(86a) Nitrate, phenoldisulfonic acid
(86b) Nitrate, Devarda
Symbols and abbreviations
Conversion formulas and factors
Chemical symbols, equivalent weights, and com- Mon names
Soil sampler and core retainer,
Modulus of rupture apparatus