Continuous Growing of Wheat. 
287 
2b, which was last limed in 1897, and which looked exceptionally 
well. The ground being very sodden in November, mineral 
manures could not be applied until December 18. Rape dust was 
put on plot 10b, and farmyard manure on plot lib, on March 2, 
1906, and the nitrogenous top-dressings on April 11 and May 14. 
At the latter date the most striking feature was the effect, 
on plot 2aa, of the single application (the year before) of 5 cwt. 
of lime. The influence of lime was also marked in plots 8aa 
and 8bb, as compared with the similar unlimed plots. By the 
close of June the best plot of all was undoubtedly 10b (rape 
dust), and, by way of contrast, the farmyard manure plot (lib) 
was very disappointing. This continued throughout the season, 
and the plot yielded very badly, not giving half the crop that 
the rape cake did (16*2 bushels, as against 34*5). It is very 
difficult to assign any adequate reason for this abnormal 
result, for the dung was of quite as good quality as in other 
years, and made and applied in the same way. The fact, 
however, remains, and was a common matter of observation 
by visitors to the farm throughout the season. “ Rust ” began 
to make its appearance towards the end of June, and was most 
marked on the nitrate of soda plots. The plots were cut on 
August 9, carted August 15-17, and threshed • and weighed 
on November 15, the corn being subsequently valued by an 
expert. 
The general yield was similar to that of 1905 and up to the 
average of the first twenty years. The unmanured produce 
(plot 7) was 11\ bushels per acre, and the highest yield 
35*2 bushels (nitrate of soda and minerals), this being closely 
followed by ammonia salts and minerals including 10 cwt. 
of lime, and by rape cake (34*7 and 34*5 bushels respectively), 
nitrate of soda, however, giving the more straw. The poverty 
of the farmyard manure plot (lib) has been commented on ; 
the yield was only 16*2 bushels, as against 32*45 bushels in 
1905. Another anomaly is that with plot 3 (nitrate of soda 
only), which, though it looked at one time distinctly inferior, 
gave 2 bushels more corn than the same amount of nitrate 
with minerals (plot 6). The effects of these anomalies can 
only be eliminated, or their causes explained, by a long 
series of experimentation and observation such as is pursued 
at Woburn. While ammonia salts alone (2a) produced but 
3^ bushels, the effect of 2 tons of lime put on in 1897 was to 
increase this (2b) to 26*1 bushels and to exceed by 3 bushels 
the yield from nitrate of soda alone (plot 3). Even the 5 cwt. 
of lime put on plot 2aa in 1905 raised the produce to 19*2 
bushels, and the remarkable appearance of this plot as com- 
pared with plot 2a was a perfect “ object lesson ” to the many 
visitors who came to the farm. 
