19 



consecutive periods of 10, 10, and 5 years, 1852 to 1870 

 inclusive. Selections from the results of most of these 

 ash-analyses have been published in No. 71 (1886), and 

 they have proved to be of much interest. 



It is very desirable that complete ash-analyses, and 

 nitrogen determinations, should soon be made in the 

 case of " mixed-year " samples, of the grain and of the 

 straw separately, especially of Plots 2 A, and 4A, but 

 also of Plots 1A and 1AA, for the five years 1877-81, 

 for the five 1882-86, and for the five 1887-91 (or 

 for the 10 years 1882-91); in continuation of the 

 results previously obtained for 10, 10, and 5 years 

 (1852-76), as above referred to, for the further illus- 

 tration of the influence of exhaustion, and of full 

 supply, on the amount, and on the composition, of the 

 produce. 



There can be no doubt that it is desirable to continue 

 to take and to preserve samples of the produce of most 

 of the continuous barley plots, and also to determine the 

 amounts of dry matter and of ash, and to preserve the 

 ashes; though, as above suggested, it is a question 

 whether, or when, the sampling from some plots 

 may be discontinued. But here, as in the case of the 

 wheat, it is to be borne in mind that the crop history 

 is unique, and that it is desirable to have the means of 

 reference and selection for the consideration of points 

 other than those which present knowledge and require- 

 ment may suggest. 



3. The Soils of the Continuous Barley Plots. 



The experiments were commenced in 1852, but the 

 first soil samples were taken in 1868, and then only 

 from 4 selected plots. Samples were taken at 4 places 

 on each plot, and in each case to depths of 3 times 

 9 inches, or to a total depth of 27 inches. For each 

 depth, a mixture was made from the samples from the 



B 2 



