TABLE LXIX.

Modes of Applying Fertilizers on Cotton. --Darlington Farm. Plats 1-20 acre each. Checked
Averages of duplicates for 1889.

When allowance is made for probable error, in every case except one the two methods gave nearly the same results. When only the half amount of nitrogen was used, drilling gave, as at Spartanburg, the best returns.

d. Averages of the Three Farms.-Table LXX. gives the averages

of the three farms.

It will be noticed that when the full amount of nitrogen was applied, the two methods gave almost exactly the same results, but that drilling gave better returns than broadcasting when smaller amounts (half doses) of nitrogen were used.

When the cotton seed was used, either finely or coarsely ground, one method, both at Columbia and Darlington, gave very nearly the same averages for the two years.

From all the results of the above tests, it would appear to follow that where heavy amounts of fertilizers are used one mode of application answers just as well as the other, but that moderate amounts can be applied more effectively in the drill. When applied by hand, the cost of each method is the same.

8. TIME FOR APPLYING NITRATE OF SODA.

Whether nitrate of soda should be applied along with the other fertilizers at the time of planting, or later on, in one or more top dressings, is an open question. The following tests bear directly upon it. They were begun in 1889 at Columbia and Darlington.

a. Columbia Farm.-The full amount of nitrogen, together with full amounts of potash and phosphoric acid, was applied in two dif ferent ways. In the first, half was applied at the time of planting, along with the potash and phosphoric acid, and half later in the spring, after growth had actively commenced. In the second, half the nitrogen was applied as a top dressing at the same time as the top dressing in the first, and half about three weeks later. The results of the two applications are given in Table LXXI.

TABLE LXXI.

Time of Applying Nitrate of Soda on Cotton.-Columbia Farm. Plats 1-20 acre each. Dickson's Improved. Checked 4 ft. x 3 ft. Averages of Duplicates for 1889.

After allowing for probable error, there is a slight difference in

favor of applying all the nitrate of soda in top dressings upon the growing crop.

b. Darlington Farm.-The soil selected for the duplicate tests immediately adjoined the other plats devoted to the experiments with cotton, and was of apparently uniform mechanical and chemical composition throughout. But the difference between the yields of the two duplicates of each test was so great as to vitiate the results. It far exceeded the probable error in the other series of tests. The results are, therefore, only given here in order to preserve the history of the tests, and must be accepted with great caution. The full amount of nitrate of soda was applied in four different ways. In (1) of the following table all of it was applied along with the potash and phosphoric acid at the time of planting. In (2) half was applied at planting, and half as a top dressing upon the growing crop later in the spring. In (3) it was applied as one top dressing at the same time as in (2). In (4) half was applied as a top dressing at the same time as the top dressing in (2) and (3), and half about three weeks later. Half doses of nitrogen, along with full doses of potash and phosphoric acid were also applied in two different ways. In (5) the half dose of nitrogen was applied as a top dressing at the same time as in (2), and in (6) in two equal top dressings at the same time as in (4). A quarter dose of nitrogen (along with full amounts of the other two constituents) was also tried as a top dressing, applied at the same time as in (2). The results of the tests are given in Table LXXII.

21-ES

TABLE LXXII.

Time of Applying Nitrate of Soda on Cotton. -Darlington Farm. Plats 1-20 acre each.
McIver. Checked 4 ft. x 3 ft. Averages of Duplicates for 1889.

The results are too conflicting to admit of discussion. They show, however, the great importance of securing uniform plats and the necessity of duplicating field tests. It was only the difference in the yields of the duplicate plats of each test that revealed the inequalities in the physical or chemical conditions of the soil of the different plats.

9. DIFFERENT PROPORTIONS OF NITROGEN, PHOSPHORIC ACID, AND

POTASH FOR COTTON.

The tests of this subsection were designed to be supplementary to those of Subsection 1. The results of the tests of that subsection for 1888 seemed to indicate that the proportions of the three constituents, based upon the amounts of each, found by analysis in the plant, was not the true one. It will be remembered that full amounts and three-fourths, one-half, and one-fourth of the full amounts of nitrogen were tested, but only full and half doses of potash and phosphoric acid. Also, that when a smaller dose of one was tested, full amounts of the other two were used along with it. The average