200 



TABLE I. Loss OF CARBONATE OF LIME 



FROM ROTHAMSTED SOILS. 



(i) Another plot more fairly comparable with the plots which follow 

 of 675 Ib. p. acre, corresp. to 756 kgr. per hectare. 



lost at the rate 



Another problem was set up when Dr. Voelcker observed that 

 the soil of the permanent wheat and barley plots at Woburn, which 

 had been receiving ammonium salts for about 20 years, had become 

 actually acid to litmus paper and had rendered the land unable to 

 carry barley without a comparatively light dressing with lime. 



It was observed also that one of the Rothamsted fields con- 

 tained plots which were cut for hay every year and on which the 

 soils had become acid through the application of ammonium salts 

 year after year for a long period. 



Half of each of these plots was limed, 2000 Ibs per acre having 

 been applied in 1903 and again in 1907. 



Table II shows the great increase of crop which has followed 

 the liming. 



