xiv CONTENTS 



PAGE 



THE EFFECT OF PHOSPHATES ON THE ACCUMULATION OF 



NITROGEN IN GRASS-LAND 75 



THE RELATION OF PHOSPHATES TO THE ACCUMULATION OF 



NITRATES IN GRASS-LAND . - 77 



THE INFLUENCE OF PHOSPHATES ON SOIL BACTERIA . . 86 



FACTORS LIMITING THE YIELD OF HAY AND THE ACTION 



OF PHOSPHATES ON HEAVY CLAY SOILS . . . 89 



THE EFFECT OF RAINFALL ON THE YIELD OF HAY FROM THE 



UNTREATED PLOTS . . . . . 89 



THE EFFECT OF RAINFALL ON THE YIELD OF HAY FROM THE 



PLOTS RECEIVING PHOSPHATES . .:. . . 92 



THE SECOND LIMITING MANURIAL FACTOR . . . . 95 



THE ACTION OF BASIC SLAG ON THE ACIDITY OF THE 

 SOIL AS MEASURED BY THE 'LIME REQUIREMENT' 

 AND HYDROGEN ION CONCENTRATES OF THE SOIL 99 



REFERENCES . . . . . . ^ . . . .108 



INDEX 110 



