The Rothamsted estate was divided into small fields, and the effects of the various crops on the fields with and without manure were carefully noted. Soils were analyzed before the crops were planted, and also after the crops were harvested, to determine the loss or gain of nitrogen.
The rotation of crops was studied thoroughly, and beans and peas were then made one in a four-course rotation. But even earlier than 1844 it had been observed that leguminous plants, of which there are thousands distributed over this sphere, had a beneficial effect on the land for the succeeding crop. At Rothamsted the legumes, or such of them as beans, peas or red clover, were thoroughly tried, and it was invariably found as one in a rotation of four to produce the same results. In some way that they then could not explain, the land after a crop of legumes was very much richer in nitrogen, amounting in many instances to 300 pounds per acre. These worthy gentlemen kept on for years trying to account for the phenomenon and endeavored to discover the true source of nitrification. But to the French chemists Schlosing and Muntz belong the credit of establishing by experiment the true nature of nitrification. Their first paper on the subject appeared early in 1877, or only twenty-nine years ago. They wished to ascertain if the presence of humic matter was essential to the purification of sewage by soil, and for this purpose they conducted an experiment, in which sewage was passed slowly through a column of sand and limestone. Under these circumstances complete nitrification of the sewage took place. They then allowed a chloroform vapor to fall for some time on top of the column, the sewage passing as before. Nitrification now entirely ceased and was not renewed for seven weeks, though the supply of chloroform was suspended. A small quantity of nitrifying soil was shaken with the water and the turbid extracts poured on the top of the column. Nitrification at once recommenced, as strongly as before.
To appreciate the force of the experiment, Muntz had previously shown that chloroform was a means of distinguishing between the action of a simple ferment as diastase, and a living organism, as yeast, the chloroform having no influence on the work of the unorganized ferment, which immediately stopped the activity of a living agent. The above discovery of Schlosing and Muntz of the true theory of nitrification of the soil was the greatest achievement to the agricultural world, inasmuch as it has been demonstrated by numerous eminent chemists and proved to be an ascertained fact; and this problem solved, which had occupied the ablest scientific minds for centuries. Now we hope for some advancement with the farmers of the United States in the future. With the discovery of Schlosing and Muntz there is no necessity for such an idea as wornout land, as is prevalent in this great country, where the chief occupation of the agriculturist has been in exploiting his land, just in the same manner as everything else has been exploited. With an ever increasing population of this sphere, there is no need to fear the earth’s capacity in producing enough to supply all their wants. That is when our farmers realize the paramount importance of the above discovery, and begin to see how bountifully an all-wise Creator has provided for us in placing these legumes on this earth for the benefit of mankind. They are a double blessing to us, for they not only abstract nitrogen from the atmosphere and deposit it in the ground for the succeeding crops, and restore the fertility of the land, but also, when they are made one in a four-course rotation, fill the soil with fibre or roots, which no soil can be in its highest productive condition without.