The plats were ploughed May 14, but from the heavy rains that soon followed, which are noticed in the account of the drainage, the after-cultivation was delayed until May 25, and the corn was not planted until a week later.

"Longfellow corn" was planted June 2, in hills, fortyfour inches apart each way. The soil was in fine condition, and the plants came up evenly on the 8th inst., looking healthy and vigorous.

As the first and second days of June were the first really warm days of the season, the late planting did not at the time seem to be a serious disadvantage.

The cultivation of the crops was as follows: Cultivated, June 15; hand hoed, June 18; thinned to four plants in a hill, June 21; cultivated and hoed, without hilling, June 26, July 9 and 25; and a final hoeing, which was limited to killing the weeds that had survived the previous treatment, was given August 2.

The plats were quite free from weeds on the start, and the repeated cultivation and hoeing left the crop perfectly clean in its subsequent growth.

On the night of September 3 a hard frost severely injured the corn, and it should have been cut up the following day; but as we were dependent on the farm for labor, we were obliged to wait until the 7th inst., when the crop was cut close to the ground and put in stooks to cure. The leaves were considerably" wilted," but the stooks were not apparently injured.

The corn was husked October 18 by the "juniors," who volunteered their services, so that all the plats could be husked in one day. The corn and stalks were hauled to the barn and separately weighed, but the corn from plats fifteen, seventeen and nineteen was not weighed until the next morning. In Table I. the weight of corn and stalks is given for each plat: -

It should be noted that from an error in making and planting, made by the unskilled hands assigned me, it became necessary to transplant several rows of corn on plats 13, 15 and 17, and that although the greatest care was taken in the work, the transplanted hills were checked in their growth and never fully matured. This will, in part at least, account for the lower yield of both stalks and corn on these plats.

The corn from plats 0, 1, 3, 5, 7, 13 and 19, was put in thin bags and placed on racks suspended by wires over the barn floor for further drying; and the stalks from plats 0, 1, 3, 5 and 7 were likewise separately stored, so that they could be again weighed.

These reserved samples were re-weighed November 17, with the results given in Table II. The loss in drying, per acre, is given in italic.

Both stalks and corn are still preserved for weighing at intervals during the winter and spring:

DRAINAGE WATERS FROM EXPERIMENTAL CORN PLATS.

As an introduction to this subdivision of my report, it may be well to make a condensed statement of some of the results of the latest researches in regard to the relations of the soil to the supplies of plant food which have prompted me to give such prominence to the investigation of drainage waters in the Plan of Experiments," drawn up for the consideration of the Board of Control.

It has long been known that nitrogen, in some form, was essential in the processes of plant-growth, but its immediate source and the form in which it could be appropriated were matters of conjecture only, while the abundance of free nitrogen in the atmosphere furnished the basis of hypotheses that have not stood the test of experimental investigations.

The researches of Boussingault, in connection with the later and more exhaustive experiments of Lawes and Gilbert

and Righ at Rothamstead, seem to show conclusively that the free nitrogen of the atmosphere is not the direct source of the nitrogen of plants.

From later investigations it appears to be settled that most of our farm crops, and particularly the cereals, take up nitrogen only in the form of nitric acid; but it is perhaps probable that leguminous plants, and possibly Indian corn, may make use of nitrogen in organic combination, which is not available for other plants.

According to the latest report (1883) on the rainfall at Rothamstead, the total amount of combined nitrogen in the average annual rainfall, of twenty-nine inches, is estimated by Lawes and Gilbert and Warrington at 4.5 lbs. per acre, and they say, "As to the amount of gain by absorption by the soil, there is unfortunately no direct or satisfactory evidence at command. From such evidence as does exist, we are disposed to conclude that with some soils the amount will probably be greater, and with others less than that supplied by the rainfall.”

It will not, therefore, be safe to estimate the atmospheric supplies of nitrogen at more than 10 lbs. per acre, annually, and this must be obtained through the medium of the soil, the direct absorption of the ammonia of the air, by plants, being so slight that practically it need not be noted.

As our farm crops contain on the average from twenty-five to considerably more than one hundred pounds of nitrogen per acre, we must look to the soil and to the manures applied as the principal source of available nitrogen.

A large part of the nitrogen of the soil is in organic combination, but nitrogen in this form, as well as that in nitrogenous organic substances and ammonia salts that are applied as manure, must be transformed into nitric acid before it is available for plant growth.

But little has been known in regard to this process of nitrification until within a few years past, notwithstanding the theories that have been formed to account for it.

From the experiments of Schloessing and Muntz, which were first published in 1877, it is evident that the nitrification of soils is caused by a living organism, which acts as a

ferment, and they afterwards, by a system of cultivations, isolated and identified the specific form as a member of the family of bacteria.

The experiments on nitrification made by Warington at Rothamstead in 1877, 1878, and 1879, have fully substantiated the claims of the French chemists, and furnished additional information of practical value in regard to the rôle of the bacterium that performs such an important part in the process of vegetable nutrition.

These bacteria abound in every fertile soil, and as a function of their vital activity are constantly transforming the nitrogen of organic substances and of ammonia, in the surface soil, into nitric acid, when the proper conditions of moisture and temperature are present.

The bacteria of nitrification are most active at a temperature of about 99° F. they act slowly when the temperature is lowered to near the freezing point, or when it is raised to 122° F., and at 131° F. their peculiar function as a ferment ceases.

Another important condition is essential to rapid nitrification, namely, the presence of an excess of some salifiable base, as carbonate of calcium, so that nitrates can be readily formed. This accounts for the action of lime when applied to peaty soils, which has not heretofore been satisfactorily explained.

The nitrates, as found, may be at once taken up by the roots of living plants, or, in their absence, they will bə washed by the rains to the lower strata of the soil beyond the reach of shallow-rooted plants, or they may be lost entirely in the drainage waters.

It must therefore be seen that the nitrification of soils, and the conservation of the nitrogen in the form of nitrates are biological processes involving the activities of living organisms.

During the summer the process of nitrification is carried on rapidly, and the nitrates are taken up by the growing crops; but after harvest, on cropped land- and where land is fallowed the nitrates accumulate in the surface soil until the fall rains wash them down to the lower strata.

A few examples from the experiments at Rothamstead will sufficiently illustrate the behavior of the nitrates in the soil.