EXPERIMENTS WITH CORN.

This series of experiments was made for the purpose of determining the relative fertility of unmanured experimental plats, with reference to obtaining a reliable standard of comparison in field experiments.

In my report on experiments for the year 1866, the variations observed in the productiveness of unmanured experimen-tal plats, of apparently the same quality and texture of soil, were referred to as a difficulty in the way of obtaining a reliable standard of comparison by which the results of field experiments may be measured. (See Report of Secretary of Board of Agriculture, for 1866, p. 59.)

In accordance with the suggestions then made, the following experiment has been planned for the purpose of avoiding this source of error in the determination of results.

Twenty-four plats of uniform size, (two rods by four rods,) were staked off on the lawn north of the Boarding Hall, each of which is designated by a number and letter, so that the experiment can be readily divided into several parallel series. These plats occupy part of the ground under experiment in the surface application of manures in 1864-6. (See Report of Secretary of Board of Agriculture for 1866, p. 55.) The outline of the original plats is traced on the office record of the present experiment, and a careful examination of the results, shows that the fertilizers applied in 1864 have produced no perceptible effect the present season. The soil is a light sandy loam, of uniform character, so far as can be determined by its physical properties and appearance, excepting at the southeast corner of the piece.

Plats A. 4, B. 4, and parts of plats A. 3, B. 3, C. 3, and C. 4, occupying the lowest portion of the ground, have a soil considerably darker than that of the other plats. The surface of the piece is nearly level, there being but a slight descent to the south-east, towards the above mentioned plats.

With the exception already noticed it would be difficult to find a piece of ground presenting a greater uniformity in the appearance of its subdivisions. At the north side of the piece several smaller plats have been added, to fill out the triangular piece along the plank road. The following plan will show the arrangement of the plats, together with the produce of corn and of stalks on each plat. The weights are given in pounds and decimals of a pound, the corn being weighed in the ear.

No manure of any kind has been applied to these plats since the year 1864, as described in the report on the surface application of manures. The plats have all been treated in the same manner, the same amount of labor having been expended on each. The sod was plowed under with a flat furrow about five inches in depth, on the 8th day of May. On the 19th the surface was fitted for planting, by the use of the cultivator and harrow. Yellow Dent corn was planted in hills four feet apart each way, on the 20th. June 16th the corn was cultivated and hoed, the plants being thinned to a uniform number in each hill. On the 14th of July the corn was again cultivated, and on the 16th it was hoed. The corn made a slow growth during the first part of the season, and for a time it was thought that the crop would prove an entire failure. On the 22d of September the corn was cut up at the bottom, and put in "stooks." The plats were all husked on the 12th of October, the corn being separately weighed on each plat. The corn was of inferior quality, the severe drought interfering with the maturity of the crop. On the 15th of October the stalks were hauled, the produce of each plat being weighed by itself. In the following table (No. 1,) the yield for each plat is given per acre, together with the average of the plats having the same letter. In the second column of the table, the estimated amount of shelled corn is given, reckoning seventy pounds of ears equal to a bushel of fifty-six pounds of shelled

corn.