CONTENTS.

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INTRODUCTION .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 167

A.—GENERAL CONSIDERATIONS AFFECTING THE OCCURRENCE OF SOLUBLE SALTS IN SOILS— Nature of the soluble salts .. .. .. .. .. .. .. .. .. .. .. .. .. .. 167 Origin of the soluble salts .. .. .. .. .. .. .. .. .. .. .. .. .. .. 167 How the salts may accumulate .. .. .. .. .. .. .. .. .. .. .. .. .. 167 Relation of vegetation to the salts .. .. .. .. .. .. .. .. .. .. .. .. 167 Topographical features and the salts .. .. .. .. .. .. .. .. .. .. .. .. 168 Soluble salts in general .. .. .. .. .. .. .. .. .. .. .. .. .. .. 168 Selective power of drained lands .. .. .. .. .. .. .. .. .. .. .. .. .. 168 Soil alkali .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 168 Crop tolerance for soluble salts .. .. .. .. .. .. .. .. .. .. .. .. .. 168 No maximum limit for salts .. .. .. .. .. .. .. .. .. .. .. .. .. .. 169

B.—SOLUBLE SALTS IN THE ESPERANCE LANDS— General Considerations .. .. .. .. .. .. .. .. .. .. .. .. .. .. 169 Location of soil samples .. .. .. .. .. .. .. .. .. .. .. .. .. .. 170 Analysis of the soil samples .. .. .. .. .. .. .. .. .. .. .. .. .. .. 170 Comparison of the results .. .. .. .. .. .. .. .. .. .. .. .. .. .. 170 Discussion of results .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 171 Relative importance of salts found .. .. .. .. .. .. .. .. .. .. .. .. 171 Lands under Crop .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 171 Bush Lands adjoining Crops .. .. .. .. .. .. .. .. .. .. .. .. .. .. 171 Bush Lands remote from growing crops .. .. .. .. .. .. .. .. .. .. .. .. 172 American experience .. .. .. .. .. .. .. .. .. .. .. .. .. .. 172 Sulphates and carbonates .. .. .. .. .. .. .. .. .. .. .. .. .. .. 172 Data available for sodium chloride .. .. .. .. .. .. .. .. .. .. .. .. .. 172 Study of salt action upon crops .. .. .. .. .. .. .. .. .. .. .. .. .. 173 Salt in miscellaneous bush lands .. .. .. .. .. .. .. .. .. .. .. .. .. 173 The general indications .. .. .. .. .. .. .. .. .. .. .. .. .. .. 174 Results of the former inquiry .. .. .. .. .. .. .. .. .. .. .. .. .. .. 174 Earlier figures of minor value .. .. .. .. .. .. .. .. .. .. .. .. .. 175 Salinity varies from place to place .. .. .. .. .. .. .. .. .. .. .. .. .. 175 Migration of salt to lower ground .. .. .. .. .. .. .. .. .. .. .. .. .. 175 Water supply and dams .. .. .. .. .. .. .. .. .. .. .. .. .. .. 176

C.—SUMMARY AND CONCLUSIONS .. .. .. .. .. .. .. .. .. .. .. .. 176 APPENDICES .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 177-193