WE HAVE endeavored to show that, for economical use in the garden, many of the commercial fertilizers are too poor in nitrogen. In order to get the necessary amount of nitrogen, we are obliged to use far more phosphoric acid and potash than our plants need.

The practical deduction from these facts is, that we should (1) buy nitrogen, phosphoric acid and potash separately and do our own mixing, or (2) if we buy them mixed and ready for use, we should select those brands which, in addition to phosphoric acid and potash, contain the highest percentage of nitrogen.

As things now are, most gardeners will find it more convenient to buy their fertilizers ready mixed. And we may congratulate ourselves that, as a rule, our fertilizer manufacturers are giving us just what they promise us, and at rates which are not unreasonably high. If we do not get what we want, and thus waste our money, we have no one to blame but ourselves. If we want to put on an acre 50 lbs. of nitrogen, 30 lbs. phosphoric acid and 30 lbs. of potash, and buy a " complete fertilizer " guaranteed to contain 2 per cent of nitrogen, 10 per cent. phosporic acid and 4 per cent. potash, we should have to use, in order to get the 50 lbs. of nitrogen, 2,500 lbs. of the fertilizer. If we bought a fertilizer containing 4 per cent. nitrogen, and a proportionally less amount of phosphoric acid and potash, we should need to use only 1,250 lbs. in order to get the same results. If we bought a fertilizer containing 6 per cent. of nitrogen, and a proportionally less amount of phosphoric acid and potash, we should need to use only 833 lbs. of the fertilizer to produce just as much good as 2,500 lbs. of the fertilizer containing only 2 per cent. nitrogen.

There is this to be said, however, in favor of using fertilizers containing an excess of phosphoric acid and potash. If we use more nitrogen than we need, we run the risk of losing it by leaching the next winter, while if we use too much phosphoric acid and potash, they are converted into insoluble compounds in the soil and are not liable to wash away. Sooner or later they will become available for future crops.

Hence, a safe rule is to make sure of having sufficient phosphoric acid and potash in the soil, or in the manure, and then buy nitrogen at the cheapest rate and in the most available form. Practically, as things now are, this means buying the so-called "high grade" fertilizers, or fertilizers containing, besides phosphoric acid and potash, the highest percentage of nitrogen. On our own farm, we do not use these high grade fretilizers. We buy a superphosphate which furnishes the greatest amount of soluble phosphoric acid at the cheapest rate. For potash, we depend principally on the store left from previous applications of barn-yard manure or from that supplied by the soil itself. On poor, sandy soil, we would furnish it in wood ashes or (cheaper still) in potash salts.

The nitrogen can be purchased in many forms, such as dried blood, sulphate of ammonia and nitrate of soda. Last spring nitrate of soda was very high. This spring, at the present time, it is lower than ever before. At the head of our article in the February number of The American Garden, the editor, probably in order to call more attention to it, wrote "forty years' experience." It is true that we have been using commercial fertilizers for 45 years - commencing with Peruvian guano, then superphosphate, potash, soda, magnesia, sulphate of ammonia and finally nitrate of soda. But to-day we feel as keen an interest in the subject as ever, and are looking to our experiment stations for reliable information on many points not fully understood. And we were particularly pleased with the experiments of Prof. Bailey, of Cornell University, on tomatoes, and not less so with those of Prof. E. B. Voorhees, of the N. J. Experiment Station, an account of which is just received.

It was at one time thought that tomatoes required poor land - that if the land was rich the plants would run too much to vines and produce little fruit, and that little late. When ordinary stable manure is used there is some truth in this opinion - as there is in all opinions based on experience. The remarks we made last month * in regard to the importance of getting early growth and the difficulty of getting this early growth by the use of common manure without producing an injurious late growth, apply to tomatoes and probably to many other garden crops. At any rate, we have made the land for tomatoes rich with nitrate of soda and superphosphate, and have had dark-green leaves and luxuriant growth of vines without injury to productiveness or maturity.

Prof. Voorhees' experiments were admirably planned, and were carefully carried out by Mr. Housell, and clearly demonstrate that we can make land rich for tomatoes without injury and with decided profit. And, of course, when we say "make land rich," we mean the use of some manure or manures that furnish nitrogen. There is no way of making land rich for garden crops without using nitrogen. Both Prof. Bailey and Prof. Voorhees selected nitrate of soda as the source of nitrogen, and this was the fertilizer, in connection with superphosphate, used at Moreton Farm.

We have thus three independent experimenters, all of whom found decided advantage in using nitrate of soda on tomatoes. The principle here involved is of vast practical and theoretical importance.

* American Garden, February number, page 91.

Prof. Voorhees' experiments were made on the farm of Mr. C. M. Housell, Middlesex county, N. J. Mr. H. is an intelligent, practical market gardener, and the soil on which the experiments were made has been used for growing market garden produce for ten years, and is consequently in high condition. It consists of a sandy loam, is level! well drained and of uniform quality. Late in the fall of 1888 the land was sown with rye. In the spring of 1889 the rye was plowed under as a green manure. The manure and fertilizers were used May 7, and the tomato plants set out immediately afterwards, four feet apart each way. Details of the experiments are given in Bulletin 63, N. J. Ag. Ex. Station, New Brunswick. Some of the more important results are :

The above manures and fertilizers were all applied May 7. On an adjoining plot, 160 lbs. of nitrate of soda was sown May 7, and again, on June 12, when the tomatoes were beginning to set, another dressing of 160 lbs. nitrate of soda was sown on the surface around the plants. This plot produced a crop which sold for $369 per acre. The first dressing yielded a profit of $85.25 per acre ; the second dressing, a profit of only $3.87 per acre.

It is evident that 160 lbs. of nitrate of soda per acre was all that the plants needed, or could make use of without a greater supply of phosphoric acid and potash than the soil afforded. The 160 lbs. of nitrate contained 25 lbs. of nitrogen. This is as much nitrogen as would be furnished by 1,250 lbs. of a "complete fertilizer," containing 2 per cent. of nitrogen. In fact, however, the 160 lbs. of nitrate would furnish the plants, early in the season, more nitrogen than 1,250 lbs. of the " complete fertilizer " because it is in an available condition, whereas that in the complete fertilizer would have to be converted into nitrate before the plants could use it.

In addition to the above experiments, however, Professor Voorhees made others that are worthy of consideration. The results may be tabulated as under:

It will be seen that the addition of phosphates and potash to the 160 lbs. of nitrate of soda had no effect. The reason for this is that the soil could furnish enough phosphoric acid and potash for all that the crop produced by the 160 lbs. of nitrate required. But when an additional 160 lbs of nitrate of soda was used, then the phosphoric acid and potash came into play, and the crop brought $429.38 per acre.

It will be seen, furthermore, that the 320 pounds of nitrate applied May 7, on plot £, did not have as great an effect as the same amount of nitrate of soda applied at two dressings, on plot D.

Several reasons for this result may be given : First, 320 pounds of nitrate of soda is more than the tomatoes on this soil (already in good condition) could utilize. In no case did the second 160 lbs. of nitrate of soda produce as great an effect as the first 160 lbs. Second, the first application of nitrate was made May 7. On May 31st, a heavy wind and rain storm set in and continued four days. It is quite possible, therefore, that on this sandy loam the four days rain may have more than saturated the soil and carried the nitrate into the sub-soil beyond the immediate reach of the roots. The second dressing, therefore, June 12, after the rain had ceased and the tomatoes were beginning to set, furnished the additional nitrogen that the plants needed. Had there been a drouth at this time, instead of a four days rain, the results might have been precisely the opposite. In other words the one dressing at once might have been better than the same quantity applied twice. The second application during a drouth would have done little good.

Third. It is quite probable that a too liberal application of nitrate of soda at the time of setting out the plants, especially if, as in these experiments, the nitrate was sown, not broadcast over all the land, but for a foot only on each side of the plants, may have induced a too luxuriant growth of vines ; whereas, if applied after the fruit was set it may have favored the growth and early maturity of the fruit.

Whatever the explanation, we take the liberty of thanking Professor Voorhees and Mr. Housell for their extremely interesting experiments, and of expressing the hope that many similar ones will be made, not only on tomatoes but on other fruits. If it is found that an early application of nitrate, in connection with other fertilizers, will produce a vigorous, healthy growth early in the season, and that this vigorous condition, with plants full of rich sap, has a tendency to ward off, or resist, or endure with comparative impunity, the attacks of insects and fungi; while after the fruit is set and we no longer desire a growth of vine or wood, if it is found that a second application of nitrates will increase the growth, size and quality of the fruit, we shall enter on a new era in fruit-growing and gardening.

It may surprise many gardeners that 20 tons of fine barn-yard manure did not produce as large a crop of tomatoes as 160 lbs. of nitrate of soda. The 20 tons of manure contained not less than 160 lbs. of nitrogen, while the nitrate of soda contained only 25 lbs. And that the great effect produced by the nitrate of soda was due to the nitrogen, there is abundant evidence. Why then, did not the 160 lbs. of nitrogen in the manure do as much good as the 25 lbs. in the nitrate ? Simply because the nitrogen in the manure has to be converted into nitrate before the plant can use it.

Moreton Farm. Joseph Harris.