CHAPTER VII 



EXPERIMENTS UPON ROOT-CROPS GROWN CONTINUOUSLY ON THE 



SAME LAND 



I. Experiments upon Mangolds, Barn Field, 1876-1911 : 



A. Effect of Nitrogenous Manures. 



B. Effect of Mineral Manures. 



C. Comparison of Nitrate of Soda and Ammonium-salts as sources of 



Nitrogen. 



D. Effect of Nitrogenous and Mineral Manures when used in Con- 



junction with Dung. 



E. Proportion of Root to Leaf. 



F. Proportion of the Nitrogen recovered in Crop to that supplied in 



Manure. 



G. The Composition of the Mangold Crop as affected by Manuring. 

 Practical Conclusions. 



II. Experiments upon Turnips, Barn Field, 1843-70. 

 Practical Conclusions. 



III. Experiments on the Continuous Growth of Potatoes on the same Land, 



Hoos Field, 1876-1901. 

 Practical Conclusions. 



IV. Experiments on the Growth of Sugar-Beet, Barn Field : 



A. First Series, 1871-75. 



B. Second Series, 1898-1901. 

 Practical Conclusions. 

 References. 



As the original design of the E-othamsted Experiments 

 embraced all the crops of the farm, so essential a feature of 

 English farming as the root-crops naturally occupied a 

 prominent place ; indeed we find that the second paper of 

 experimental results issued from Kothamsted in 1847 dealt 

 with turnip culture. In 1843, accordingly, the Barn field was 

 set aside for experiments on turnips, the trials being on 

 Norfolk white turnips for six seasons, 1843-1848, followed by 



