COMPARISON WHEN GROWN IN ROTATION 75 



plots has gone up, as may be seen from diagram Fig. 10, which 

 shows the average yield of grain on the unmanured plot, on 

 the dunged plot, and the mean of the three plots completely 

 manured with artificial manures. The decline in the production 

 of the dunged plot is the least marked, although considerable. 



Again, the Agdell field, which comes into barley every 

 four years, has shown a decline in its yield of barley during 

 the last fifty years, which is very similar to that of the 

 continuous barley plots when the yields of each field are 

 compared for the same years. Table XXXI. shows the total 

 produce from the, unmanured and two of the completely 



TABLE XXXI. Barley, grown continuously, Hoos Field, and in four-course 

 rotation, Agdell Field. Comparison of the Total Produce (Grain and 

 Straw) per acre in the years 1853, '57, '61, '65, '69, 73, 77, '81, '85, 

 '89, '93, '97, 1901, '05, '09, and '13. 



Now Plot 5. 



t Now Plot 2. 



manured plots in the Hoos field for the years when barley 

 was grown in the Agdell rotation field, for which field the 

 crops on the unmanured and the most highly manured plot 

 are also given. It will be seen that the barley crop grown in 

 rotation on the plot that is highly manured (a complete manure 

 is put on for the preceding Swede crop, which is returned 

 to the land) showed until 1901 the same decline in yield as the 

 crop on completely manured plots growing barley continuously, 



