Joseph Harris says, “Some years ego we used nitrate of soda cautiously as a top dressing on the celery plants.  The effect was astonishing.  The next year, having more confidence, we spread the nitrate at the time we sowed the seed, and again after the plant came up, and twice afterward during a rain.

“Instead of finding it difficult to get the plants early enough for the celery growers who set them out, they were ready three weeks before tile usual time of transplanting.

“At the four applications, we probably used 1600 lb. of nitrate of soda per acre, and this would probably furnish more nitric acid to the plants than they could get from five hundred tons of manure per acre, provided it had been possible to have worked such a quantity into the soil.  Never were finer plants grown.  As compared with the increased value of the plants, the cost of the nitrate is not worth taking into consideration.”

As a means of fertilization without the use of artificial fertilizer, soil inoculation has come.  It has grown out of the discovery of the dependence of leguminous plants on bacteria which live on their roots.  The discovery is one of the most important of those made in modern agriculture.

It has received its greatest impetus in America, under the experiments of Professor Moore of the United States Agricultural Department.

The Department supplied free to farmers the bacteria for inoculation.  Now they supply it only for experimental purposes.  A laboratory has been fitted up for the work.  The method is to propagate bacteria for each of the various leguminous plants such as clover, alfalfa, soy beans, cow peas, tares, and velvet beans.  All of these plants are of incalculable value in different sections of the country as forage for farm animals.  In the West, alfalfa is the main reliance for stockraisers.  The farmers of the East are trying to establish it, but meet with difficulty chiefly for want of the special bacteria which should be found on the roots.

The function of these bacteria is to gather the nitrogen of the air and supply it as plant food.  Without the bacteria the plant can get only the nitrogen which is supplied from the soil in fertilizers.  With the aid of the bacteria the growing plant can derive the greater part of its food from the air.

Here is one of the results of the use of inoculated seed as reported by the United States Agricultural Bulletin No. 214.

G. L. Thomas, experimenting with field peas on his farm near Auburn, Me., made a special test with fertilized and unfertilized strips, and stated that “inoculated seed did as much without fertilizers of any kind, as uninoculated seed supplied with fertilizer (phosphate) at the rate of 800 pounds and a ton of barnyard manure per acre.”

This seems to be only in its infancy.  The Department warns us that nitrogen inoculation is useless where the soil already has enough nitrogen and where other plant foods are absent.