310 Report of Experiments on the Growth of Barley, 
was higher over tlio second than over the first 10 years; but 
the quantity, of both corn and straw, was between 23 and 24 
per cent, less over tlie second 10 years. 
2. Compared with wheat grown for many years in succession 
without manure, barley gave an average of more corn, less 
straw, and nearly the same weight of gross produce (corn and 
straw together) ; but the barley fell off more in produce of grain, 
and about equally in straw, over the later years. 
3. Farmyard manure applied every year for 20 years, gave an 
average annual produce of more than 48 bushels of barley- 
grain, and 28 cwts. of straw. The weight per bushel, quantity 
of grain, and quantity of straw, were all considerably higher 
over the second than over the first 10 years. The manure pro- 
bably supplied from three to four times as much nitrogen as 
any of the artificial manures, and much more of carbonaceous 
organic matter, and of every other constituent of the crop, than 
was contained in the produce. It would leave a large residue 
of nitrogenous, carbonaceous, and other matters in the soil, 
wTiich seem to be very slowly available for future crops ; but 
the large accumulation of organic matter increases the porosity 
of the soil, and its capacity for the retention of moisture ; and 
the crops are thereby rendered both less susceptible to injury 
from excess of rain, and more independent of drought. 
4. As without manure, so with farmyard manure, barley, 
compared with wheat, yielded, over a series of years, more corn, 
less straw, but nearly the same quantity of total produce (corn 
and straw together). This is remarkable, when it is considered 
that the wheat is autumn-sown and autumn-manured, and the 
barley spring-sown and spring-manured. 
5. Mineral manures alone gave very poor crops, » and the 
quantity of both corn and straw fell off considerably during the 
later years ; but superphosphate of lime alone gave more than salts 
of potass, soda and magnesia, and not much less than the 
mixture of all. It may be concluded that the soil was not 
relatively deficient in any of the mineral constituents which 
the manures supplied ; and, from the falling off in the produce 
both without manure and with purely mineral manures, it is 
probable that the growth of the crop under such conditions is 
gradually exhausting the available nitrogen accumulated within 
the soil from previous cultivation, manuring, and cropping. 
6. Over the same period of 20 years, a mixed mineral manure, 
containing salts of potass, soda and magnesia, and superphos- 
phate of lime, gave, of barley, much more grain, rather less 
straw, but considerably more total produce, than of wheat. It 
is probaljle that, with the autumn-manuring for the wlieat, the 
various constituents are distributed by the rains, or enter into 
