moisture, warmth and the activity of microbe life in the soil), are not and cannot be made alike year after year. In one year they may all be very favorable, in which case the nitrogen of cotton seed meal, for example, will have a higher availability as compared with that of nitrate; in the next year the reverse may be true. Thus in 1894 the per cent. availability of nitrogen of the same cotton seed meal was 87, in 1895, 72, in 1896, 62 per cent. of that of nitrate-nitrogen.

Nitrogen of Bone.

The tests made with the finest bone, grade A, show great irregularities, which cannot be explained. Crop No. 304 followed an oat crop whose nitrogen content was excessively large. The yield of nitrogen in the maize crop is, however, about the average of the others, so that whether this result is excluded from the corrected average or not, makes no difference in the result. The percentages representing availability of nitrogen in four of the crops are 6.7, 7.6, 11.2, and 11.5. But in another crop we have a relative availability of 22.7, and in another no more nitrogen was taken by the crop than belonged to crops which received no fertilizer-nitrogen whatever. The tests with coarser grades of bone show less wide range of results. The figures obtained are as follows:

PER CENT. AVAILABILITY OF BONE NITROGEN.

These experiments of a single year have shown that, under the conditions specified, fine bone flour prepared from the hardest bones (selected raw knuckle bones free from all tendon, cartilage, etc.), was about onethird as efficient a source of nitrogen to the maize crop as cotton seed meal, and that the coarser grades of bone supplied but very little nitrogen to the growing crop.

When the crops which have been described were harvested, the pots were planted with winter rye. The experiments must be continued for several years in order to arrive at safe conclu

ON THE USE OF COMMERCIAL FERTILIZERS FOR FORCING-HOUSE CROPS.

BY E. H. JENKINS AND W. E. BRITTON.*

I. EXPERIMENTS WITH TOMATOES, SEASON OF 1895-1896. This work is a continuation of that begun two years since and described in the Report of this Station for 1895, pp. 75 to 98.

The experiments now to be described were planned to test further the use of a mixture of coal ashes with a few per cent. of peat for forcing crops, to determine more closely the amount of nitric nitrogen which can be economically used in such a soil for growing tomatoes, and to study the effects of larger quantities of phosphoric acid than we had previously employed.

House, Benches and Plots.

The house and the arrangement of benches in it were the same as described on pp. 77 and 78 of the Report for 1895. The bench space in the house was divided by board partitions into 30 plots. These were nearly alike in shape and had the same depth (9 inches) and the same area (13.87 square feet).

Soil and Fertilizers.

Two kinds of soil were employed. One was a compost, such as is commonly used in forcing-houses, consisting of thick turf composted with one-third its bulk of stable manure and well worked over during the preceding summer.

The other soil, for each plot, consisted of 300 pounds of coal ashes mixed with 100 grams of pure calcium carbonate, nine pounds of moss peat, such as is sold in the cities for stable bedding, or with a like amount of meadow peat from a swamp near New Haven. Both ashes and peat were sifted through a wire screen having four meshes to the linear inch.f

The fertilizer chemicals designed for a plot were sprinkled on

* The general plan of this study, the arrangement of its details and the preparation of this paper are our joint labor. The horticultural work has been done wholly by Mr. Britton. The chemical analyses have been made by Messrs. Winton, Ogden and Mitchell.

Note by S. W. JOHNSON-Our use of Peat as an ingredient of the "soil" employed for experimental cultures, is the result of my experience in an investigation On the Effect of Alkaline Bodies in developing the Fertilizing Power of

the mixture of ashes and peat, and the whole was carefully and repeatedly shovelled over to secure perfect mixture.

The soil filled each plot to a depth of about eight inches. The kinds and quantities of fertilizers applied will be seen from subsequent tables.

The First Crop.

Plants. Seeds of the Lorillard tomato were sown July 25th, potted August 20th into 24 inch pots and shifted into 4 inch pots about the middle of September. Six of these plants, with the potting earth about them, were set in each of the forcing-house plots on Sept. 27th and 28th. The plants were trained to a single All lateral shoots were pinched off as they appeared, dried and carefully saved for analysis, those from each plot separately. Notes Regarding Growth.-During the period of growth, and ripening of the fruit, cloudy weather prevailed and the small yield was doubtless due to the lack of sunlight.

stem.

The plants, however, grew well from the beginning. Flowers were pollinated every second day throughout the fruiting season, Peat," made in 1862 (briefly described in the writer's "Peat and its Uses as Fertilizer and Fuel," pp. 77-81; also in Storer's Agriculture, Vol. II, p. 19), in which it was found that maize plants rooted in peat, withstood great heat and occasional drouth without apparent injury.

A mixture of Coal Ashes and Peat was first used in our Vegetation Cultures, for studying the Availability of Nitrogen in Fertilizers, Report for 1893, p. 231. The coal ashes were either those of authracite coal taken directly from the furnace of the large boiler that supplies steam heat to the Station buildings, or those of bituminous coal from the Whitney Lake Pumping House. These ashes contain some partially burned coal and considerable slag as well as pulverulent ash and clay.

The Peat was either a dark brown meadow "muck" from the Beaver Swamp meadow near New Haven, formed from grasses, sedges, etc., and rich in slowly available nitrogen, or the imported brown moss peat (Commercial Peat Moss) used as stable litter. The former is the cheaper and more convenient to pulverize. This Mixture is easily prepared in large quantities, is almost entirely sterile both as regards plant food and living organisms of all kinds; its texture and physical characters are more favorable to vegetation than those of quartz sand, usually employed, since it largely consists of mineral grains of very various dimensions intimately mixed together, and contains a small proportion of highly porous humus.

Its cheapness and the excellent results obtained with it, when duly enriched with plant food, have led us to employ it as a substitute for the usual compost. It is free, not only from iusects and worms, but probably also from the denitrifying organisms so abundant in dung, and perhaps in composts, which dissipate the nitrogen of nitrates.

beginning on October 19th. For this purpose a spoon is held directly under each flower and the upper part of the blossom gently tapped with a pencil or small stick. Pollen is thus shaken into the spoon and at the same time the stigma is coated with it, and as flower after flower is visited on many different plants, cross-fertilization is insured.

About the middle of October a fungus (Cladosporium fulvum), appeared as yellowish-brown patches on the under side of the leaves of a few plants, but was quickly checked and soon eradicated by treatment with ammoniacal copper carbonate.

On November 9th, there appeared on the leaves of a few plants the injury known as "blight," "sunscald" or "burn," which very seriously damaged some of the crops and in consequence impaired the value of the experiment. A description of this trouble is given on subsequent pages.

The surface soil of all the plots was stirred every few days to check evaporation. The plants were watered whenever it was thought necessary and the atmosphere was kept moist by wetting the walks daily between nine and ten o'clock in the morning. On sunny days the wetting was repeated in the afternoon to keep the temperature from running too high.

The temperature was maintained between 65° and 70° Fahr. at night and about 10° higher during the day.

Harvesting.-Every plant was numbered and each tomato when picked was weighed and credited to the plant which bore it. It was therefore possible to judge whether the several plants in each plot were of fairly uniform vigor and bearing capacity. The first ripe fruits were harvested November 27th from plot 35 (compost), and the next were picked December 2d from plots 12, 28 and 32 (coal ashes, etc.), and from plot 20 (compost). The yield of each plot, given in Tables I and II, pages 210, 211, will be discussed later. The experiment was concluded on January 21st, 1896.

The plants, including roots, so far as it was easily practicable to gather them, and immature fruit from each plot were dried, added to the dried trimmings of the plants saved during the growing season and the whole was weighed and analyzed to determine the content of nitrogen, phosphoric acid and potash.

Average samples of fruit from both the coal ashes and the compost were analyzed and from its composition and total weight were calculated the quantities of nitrogen, phosphoric acid and potash removed by the fruit.

The Second Crop.

Immediately after the first crop was harvested and analyzed additional fertilizers were applied to some of the plots and tomato plants were set as before on all the plots.

Seed for these plants-a portion of the same stock from which the plants in the previous experiment came-was sown on December 14th; the seedlings were put in two-inch pots on December 26th and repotted to four-inch pots on January 22d.

The plants, which had been kept in a cool house and were stocky and in excellent condition, were finally set in the plots on February 14th.

Notes on the Growth.-The plants started into thrifty growth as soon as transplanted to the benches, and, by March 16th, were about two and one-half feet high. Flowers of the third clusters were then opening and most of the second clusters had set fruit. Soon after, the plants on plots 9, 10, 11 and 12 were somewhat affected by "scald;' some blossoms fell before opening and

others failed to set fruit.

The first blossom appeared February 20th, and the blossoms were pollinated every day or two thereafter. The first ripe fruit was harvested April 21st from the coal ashes, plots 11, 25 and 29, and from the compost, plot 23.

The temperature, care and management of the house were essentially the same as for the first crop.

About May 1st many green tomatoes began rotting at the blossom end, being attacked by the common fungus (Macrosporium tomato), and ripened prematurely. The fungus was found on tomatoes grown in both coal ashes and compost, but was less prevalent on the south bench, where the flowers and fruits were nearer the glass and perhaps more fully exposed to the sun. From this time on no bottom heat could be given the plants through the night. It is quite probable that this change of condition, which noticeably checked the growth, favored the development of the fungus just referred to.

The yield, though larger than that of the first crop, on account of the increased amount of sunlight, was unquestionably lessened somewhat in every plot by the ravages of the Macrosporium.

The plants stood in the plots till July 8th, when they were harvested. The harvesting and subsequent work were the same as described for the first crop.