BARLEY. 7 1 



three years, and also the average produce over selected series 

 of years, and over the period of forty years, to 1891 inclusive. 



The first column gives the produce without manure. The 

 upper portion of columns 2 and 3 gives the produce by farm- 

 yard manure for the first twenty years (1852-1871) over the 

 whole plot. The lower portion of column 2 gives the pro- 

 duce on the half of the plot on which the application was 

 still continued ; and that of column 3 the produce on the 

 other half where the application was discontinued after the 

 first twenty years, showing therefore the effects of the residue 

 of the previous applications. Column 4 shows, for the later 

 years, the deficiency of the produce on the plot where the 

 application was discontinued compared with that where it 

 was continued ; and the last two columns show the increase 

 over the unmanured produce — first by farmyard manure con- 

 tinuously applied, and secondly by the residue of the appli- 

 cations of the first twenty years. 



First referring to the produce without manure, it is seen Produce 

 that in two years, the third and fourth, the yield was over 30 ^f^Ji 

 bushels per acre ; in six years during the first thirteen it was 

 between 20 and 30 bushels, but it never afterwards reached 

 20 bushels, and in thirty-two out of the forty years the yield 

 was less than 20 bushels ; in eighteen of these it was less 

 than 15, and in three less than 10 bushels. 



There was thus a very great variation in the amount of pro- influence 

 duce without manure from year to year according to season. A °f seasons - 

 glance at the figures, and especially at the average produce over 

 successive series of years, as given at the foot of the table, 

 shows, however, that independently of these fluctuations due 

 to season, there was a progressive decline due to exhaustion. 



It may be observed that there is, without manure, a decline Exhaus- 

 in the produce of barley-grain of 33.8 per cent over the second j^™ ™J Mr ' 

 twenty years compared with the first twenty ; and that this 

 rate of decline is considerably greater than was found in the 

 case of wheat. This result is doubtless due to the shorter 

 period of growth, and the greater dependence on the surface- 

 soil, in the case of barley ; and hence exhaustion is the sooner 

 manifested. 



Turn now to the produce by farmyard manure. As with- Farmyard 

 out manure, there is very great fluctuation from year to year manure ' 

 according to season ; but instead of a gradual decline, there 

 is an increase in the yield over the later years due to the 

 accumulation of the manure. There is, in fact, instead of a 

 decline of 33.8 per cent as without manure over the second 

 compared with the first twenty years, an increase with farm- 

 yard manure of 1.6 per cent over the later period. 



In four of the forty years the farmyard manure gave more 



