the total produce of
grain, straw, and chaff, and 1,685 lbs. have been left in the soil.

Mr. Lawes estimates, from several analyses, that his farm-yard manure
contains 0.637 per cent of nitrogen, 2.76 per cent of mineral matter,
and 27.24 per cent of organic matter, and 70 per cent of water.

According to this, the plot dressed with 14 tons of manure every year,
for 20 years, has received 3,995 lbs. of nitrogen, of which 583-1/4 lbs.
were recovered in the produce, and 3,411-3/4 lbs. were left in the soil.

In the case of barley, 3,995 lbs. of nitrogen was applied during the 20
years to the plot dressed with farm-yard manure, of which 427-1/2 lbs.
were recovered in the crop, and 3,567-1/2 lbs. left in the soil.

"I see," said the Deacon, "that barley gets less of the goodness out of
farm-yard manure than wheat, but that it gets more out of the salts of
ammonia and nitrate of soda. How do you account for that?"

"I suppose, because the manure for wheat was applied in the autumn, and
the rains of winter and spring dissolved more of the plant-food than
would be the case if the manure was applied in the spring. If the manure
had been applied on the surface, instead of plowing it under, I believe
the effect would have been still more in favor of the autumn-manuring."

When the nitrogen is in an available condition, spring barley can take
up and utilize a larger proportion of the nitrogen than winter wheat.
Neither the wheat nor the barley can get at and take up half what is
applied, and this, notwithstanding the fact that a heavy dew or a slight
rain furnishes water enough on an acre to dissolve a liberal dressing of
nitrate of soda or sulphate and muriate of ammonia. The truth is, the
soil is very conservative. It does not, fortunately for us, yield up all
its plant-food in a year.

We have seen that when wheat or barley is dressed with soluble
ammonia-salts or nitrate of soda, a considerable amount of the nitrogen
is left in the soil--and yet this nitrogen is of comparatively little
benefit to the succeeding crops of wheat or barley, while a fresh
dressing of ammonia-salts or nitrate of soda is of great benefit to the
crop.

In other words, when wheat is sown after wheat, or barley after barley,
we do not get half the benefit from the manure which it is theoretically
capable of producing.

Now, the question is, whether by a judicious rotation of crops, we can
avoid this great loss of manure?

There was a time