viii SOIL CONDITIONS AND PLANT GROWTH 



problems : the biologist constantly needs the help of 

 the statistician, the physiologist and chemist : most of 

 the work is essentially " team work," requiring close 

 co-operation between experts in different branches ot 

 science. 



The recognition of these considerations, and the fact 

 that the Ministry of Agriculture has now, through the 

 Development Fund, enabled Rothamsted to interest 

 some of the more promising of the younger scientific 

 workers in agricultural problems, justifies the hope that 

 the future will see even greater advances than the 

 past. 



In preparing this edition thanks are due to my 

 colleagues at Rothamsted who have read sections or 

 chapters of the book and made useful comments, es- 

 pecially to Miss Aslin, Dr. B. Muriel Bristol, Miss 

 Jewson, Messrs. W. B. Brierley, D. W. Cutler, E. M. 

 Crowther, B. A. Keen, and H. J. Page ; to Professor 

 V. H. Blackman, Mr. G. W. Robinson, of University 

 College, Bangor, and Dr. E. J. Salisbury ; to M. 



Georges Matisse, of Paris, who is translating this 

 edition into French ; and in America to Dr. H. L. 

 Walster for a valuable critical review and list of refer- 

 ences, and others for useful suggestions. The book has 

 been helped by so many that I hope it will still find 

 friends in spite of its larger size. 



