The lime liberated one-half the ammonia contained in the soil.
“This result,” says Prof. Way, “is so nearly the same in all cases, that we are justified in believing it to be due to some special cause, and probably it arises from the existence of some compound silicates containing ammonia, of which lime under the circumstances can replace one-half—forming, for instance, a double silicate of alumina, with half lime and half ammonia—such compounds are not unusual or new to the chemist.”
This loss of ammonia from a heavy dressing of lime is very great. A soil five inches deep, weighs, in round numbers, 500 tons, or 1,000,000 lbs. The soil, No. 1, contained .0293 per cent of ammonia, or in an acre, five inches deep, 293 lbs. After liming, it contained .0169 per cent, or in an acre, five inches deep, 169 lbs. The loss by liming is 124 lbs. of ammonia per acre. This is equal to the quantity contained in 1200 lbs. of good Peruvian guano, or 12½ tons of barn-yard manure.
In commenting on this great loss of ammonia from liming, Prof. Way observes:
“Is it not possible, that for the profitable agricultural use, the ammonia of the soil is too tightly locked up in it? Can we suppose that the very powers of the soil to unite with and preserve the elements of manure are, however excellent a provision of nature, yet in some degree opposed to the growth of the abnormal crops which it is the business of the farmer to cultivate? There is no absolute reason why such should not be the case. A provision of nature must relate to natural circumstances; for instance, compounds of ammonia may be found in the soil, capable of giving out to the agencies of water and air quite enough of ammonia for the growth of ordinary plants and the preservation of their species; but this supply may be totally inadequate to the necessities of man. *** Now it is not impossible that the laws which preserve the supply of vegetable nutrition in the soil, are too stringent for the requirements of an unusual and excessive vegetation, such as the cultivator must promote.
“In the case of ammonia locked up in the soil, lime may be the remedy at the command of the farmer—his means of rendering immediately available stores of wealth, which can otherwise only slowly be brought into use.
“In this view, lime would well deserve the somewhat vague name that has been given it, namely, that of a ‘stimulant’; for its application would be in some sort an application of ammonia, while its excessive application, by driving off ammonia, would lead to all the disastrous effects which are so justly attributed to it.
“I do not wish to push this assumption too far,” says Prof. Way, in conclusion, “but if there be any truth in it, it points out the importance of employing lime in small quantities at short intervals, rather than in large doses once in many years.”
“The Squire, last year,” said the Deacon, “drew several hundred bushels of refuse lime from the kiln, and mixed it with his manure. It made a powerful smell, and not an agreeable one, to the passers by. He put the mixture on a twenty-acre field of wheat, and he said he was going to beat you.”