The Garden Guide

Book: Gardening Science - Soils, Manure and the Environment
Chapter: Chapter 2: Manure

Salts as manures

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1326. All salts, when used as manures, must be given in very small quantities, and in a state of minute subdivision. Solutions of saline substances were used twice a week, in the quantity of two ounces, on spots of gross and corn, sufficiently remote from each other to prevent any interference of results. The substances tried were bicarbonate, sulphate, acetate, nitrate, and muriate of potassa; sulphate of soda; and sulphate, nitrate, muriate, and carbonate of ammonia. It was found, that, in all cases when the quantity of the salts equalled one thirtieth part of the weight of the water, the effects were injurious; but least so in the instance of the carbonate, sulphate, and muriate of ammonia. When the quantities of the salts were one three-hundredth part of the solution, the effects were different. The plants watered with the solutions of the sulphates grew just in the same manner as similar plants watered with rain-water. Those acted on by the solution of nitre, acetate and carbonate of potassa, and muriate of ammonia, grew rather better. Those treated with the solution of carbonate of ammonia grew the most luxuriantly of all. This lost result is what might be expected; for carbonate of ammonia consists of carbon, hydrogen, azote, and oxygen. There was, however, another result which was not anticipated; the plants watered with the solution of nitrate of ammonia did not grow better than those watered with rain-water. The solution reddened litmus paper; and probably the free acid exerted a prejudicial effect, and interfered with the result.