THE ROTHAMSTED EXPERIMENTS; 



BEING AN ACCOUNT OF 



SOME OF THE RESULTS OF THE AGRICULTURAL INVESTIGATIONS 



CONDUCTED AT ROTHAMSTED, IN THE FIELD, THE 



FEEDING-SHED, AND THE LABORATORY, 



OVER A PERIOD OF FIFTY YEARS. 



By Sir John Bennet Lawes, Bart., D.C.L., Sc.D., F.R.S., and 

 Sir J. Henry Gilbert, LL.D., Sc.D., F.R.S. 



CONTENTS. 



Introduction 



PAGE 



13 



I. — Experiments with Root-crops grown continuously ; 

 Barnfield, Rothamsted. 



Introduction ...... 



1. Experiments with Norfolk white turnips 



2. Experiments with Swedish turnips . 



3. Experiments with sugar-beet 



4. Experiments with mangel-wurzel . 

 Condition of the nitrogen in roots 

 Approximate average percentage of dry matter and of sugar in 



various roots ..... 

 General conclusions ..... 



19 

 20 

 24 

 31 

 48 

 62 



66 



67 



II. — Experiments with Barley grown continuously ; 

 Hoosfield, Rothamsted. 



Introduction ........ 68 



The field experiments on barley — 



Results without manure, and with farmyard manure . . 69 



Results without manure, and with artificial manures . . 73 



Influence of season on the amounts of produce . . .81 



Influence of exhaustion, manures, and variations of season, on the 



composition of the barley crops . . . .85 



On what does strength of straw depend ? . . . .97 



Summary and conclusions ...... 99 



