Such fertilizers probably retail at forty to sixty dollars per ton, and are fully worth it.  All this plant food, and perhaps one half more, can be drawn in a single load, while it will take ten such loads of stable manure to supply the same amount of plant food.

There is no reason to be afraid of too much fertilizer, provided it is evenly distributed and thoroughly mixed through properly prepared soil.  Stinginess in this item is poor economy.

Nitrogen is the most essential food for plant growth.  It is an important element of plant food in manure.  In ordinary manure most of the value is due to the nitrogen, although phosphoric acid and potash are also present.  It is found in the most available form in nitrate of soda.  Nitrate of soda will benefit all crops, but it does not follow that it will pay to use it on all crops.  Its cost makes it unprofitable to use on cheap crops; but on those that yield a large return nitrate of soda is a very profitable investment.

“It is shown in the experiments conducted with nitrate of soda on different crops that in the case of grain and forage crops, which utilized the nitrate quite as completely as the market garden crops, the increased value of crops due to nitrate does not in any case exceed $14 per acre, or a money return at the rate of $8.50 per 100 pounds of nitrate used, while in the case of the market-garden crops the value of the increased yield reaches, in the case of one crop, the high figure of over $263 per acre, or at the rate of about $66 per 100 pounds of nitrate.” (New Jersey Agricultural Experiment Stations, page 8, No. 172.)

Professor Voorhees, of the same station, experimented with tomatoes, with these results: 

Manure and Fertilizer Used Cost Per Acre Value of Crop

No manure $271.88 30 tons barnyard manure $30.00 291.75 8 tons manure and 400 lb. fertilizer 15.00 317.63 160 pounds nitrate of soda alone 4.00 361.13

Such common crops as tomatoes, cabbage, turnips, beets, etc., in order to be highly profitable, must be grown and harvested early; any one can grow them in their regular season; their growth must be promoted or forced as much as possible, at the time when the natural agencies are not active in the change of soil nitrogen into available forms, and the plants must, therefore, be supplied artificially with the active forms of nitrogen, if a rapid and continuous growth is to be maintained.

It is quite possible to have a return of $50 per acre from the use of $5 worth of nitrate of soda on crops of high value, as, for example, early tomatoes, beets, cabbage, etc.  This is an extraordinary return for the money and labor invested; still, if the increased value of the crop were but $10, or even $8, it would be a profitable investment, since no more land and but little additional capital was required in order to obtain the extra $5 or $8 per acre.

The results of all the experiments conducted in different parts of the country and in different seasons, show an average gain in yield of early tomatoes of about fifty per cent, with an average increased value of crop of about $100 per acre.  The rest of the report shows similar results with other crops. (New Jersey Agricultural Experiment Station, Bulletin 172.)