6 The Permanent WJieat and Barley Expenments 
regard to the application of nitrate of soda to barley, the increase 
would at the present time be obtained at a cost of not much more 
than one shilling per bushel. 
That such an amount of increase is not obtained in ordinary 
farming is quite evident. This may be traced chiefly to two 
causes ; first, to faulty application, the salts not being evenly 
distributed over the land ; secondly (and this is, perhaps, the 
most important), to the amount of weeds in the land. Weeds 
feed greedily on nitric acid, robbing the corn . of the food it 
would otherwise take up. It is true the nitric acid is not 
absolutely lost, as the ploughing down the weeds, and their 
eventual destruction under the soil, again furnishes nitric acid 
at some future time ; but the immediate effect is to render it 
necessary to use a larger amount of nitric acid to do the same' 
amount of work. 
Although the results obtained in Stackyard Field are much 
higher than can be obtained in ordinary practice, owing to the 
absolute freedom from weeds and the careful distribution of 
the manures, still there is a considerable difference between the 
amount of nitrogen applied in the manure and that which is 
taken up in the crop. If we take the mineral and nitrate manured 
barley, which shows an increase of more than 3,000 lbs. in corn 
and straw per acre over the mineral manured plot, it is probable 
that not more than two-thirds of the nitrogen applied in the 
manure are to be found in the crop ; and it is almost certain 
that in the ordinary practice of agriculture much less than one- 
half the nitrogen in the ammonia salts or nitrate of soda would 
be found in the crop to which it is applied. 
The experiments in Stackyard Field throw some light upon 
the destination of some portion of this residue. For the last five 
years a portion of the wheat and barley which has received 
minerals and ammonia, or minerals and nitrate, one year, received 
the minerals alone the next year. On the wheat land, the minerals 
which followed the minerals and nitrate of the previous year 
show no inci'ease of crop over the land which is always under 
mineral manures. Where salts of ammonia are used there is a 
gain of 2 1 bushels of grain per acre, but no gain in the straw. 
On the barley, the gain by the minerals where the nitrate was 
applied the previous year is 11 bushels and 2| cwt. of straw, 
while the gain from the previous application of salts of ammonia 
is nearly 14 bushels per acre and nearly 8 cwt. of straw. 
All this is very interesting, and tells us that we must not be 
in too great a huriy to say that ammonia and nitrates are all 
exhausted by the first crop of corn to which they are applied. 
Here we have a very light soil, without vegetation from August 
in one year to the spring of the following year, holding a suffi- 
