30 



in 2 years in that of 30 plots. The sugar was also 

 determined in the produce of the first 5 years of 

 mangel wurzel in the first year in 20 samples, and in 

 each of the succeeding 4 years in 31 samples. 

 The results of the first 3 years of the continuous 

 growth of root-crops 1843, 4, and 5 were published, 

 and discussed pretty fully, both as to the amounts of 

 produce, and to its composition, according to the 

 manures employed, in 1847. in No. 2 in the list. 



The field results for the 26 years, 1845-70, are sum- 

 marised in the " Memoranda!' 



For each of the 5 years of sugar-beet, 1871-75, the 

 produce of both roots and leaves of each plot, the per- 

 centages of dry matter and ash in the roots of each 

 plot, of sugar in those of most, and of nitrogen in those 

 of some of the plots, are given in the " Memoranda?' 



For each of the 15 years of mangel wurzel, 1876-90, 

 the produce of both roots and leaves of each plot is 

 given, and the percentages of dry matter and ash in 

 the roots of each plot, that of sugar in those of 

 most in the first 5 years, and that of nitrogen in 

 the roots of a selection of plots each year, are given in 

 the " Memoranda." 



The results, both as to produce and composition of 

 the various root-crops have been discussed in my 

 Oxford Lectures, the substance of which it is arranged 

 shall be published ; and a summary of the results was 

 given in No. 76, in 1887. 



Analyses have also been made of the ash of the juice 

 of 32 different samples of the sugar-beet. 



The present year, 1891, is the sixteenth in succession 

 of mangel wurzel ; and unless the crop should signally 

 fail from other than obviously temporary season con- 

 ditions, it will be desirable to continue the experiments 

 with mangels, which are among the most important of 

 our root-crops, for a fourth period of 5 years, that is 

 until after the removal of the twentieth crop in 1895. 

 After that time, or whenever a change is made, it would 

 be desirable to grow say 3 crops of barley without 

 manure, clover being sown with the third barley-crop, 



