5(3 



size, planted at the same time, having been plowed as a check to a 

 depth of four inches and harrowed once without disking. The yield 

 of the latter was at the rate of 26.4 bushels per acre, and of the former 

 at the rate of 33.15 bushels per acre, a gain of 6% bushels, or nearly 

 25 per cent. The cost of these three diskings and one rolling was esti- 

 mated at $1.50 per acre, making the cost of the increased yield 22 

 cents a bushel. As there was a poor stand, owing to the character 

 of the spring weather, the cost of the increased yield would have been 

 measurably less per bushel if a fair stand and start had been secured 

 in the beginning. 



In another experiment made at this same time and place the com- 

 parative values of one, two, and three diskings were brought into com- 

 parison, the treatment of the plots used being otherwise identical. For 

 this purpose three plots, each a hundred and sixty corn-rows long by 

 thirty-three rows wide, nearly an acre and a half in area and contain- 

 ing 5,280 hills, were specially plowed June 2. This ground had been 

 used earlier for an experiment with fall plowing and disking as com- 

 pared with the same treatment in spring ; and the tract was now di- 

 vided, to insure an equal character and condition, into plots at right 

 angles to the earlier ones. One of these. Plot 9 of the year's series in 

 the Galesburg field, was plowed six inches deep June 2, disked three 

 times, June 3, 4, and 6, with a 20-inch disk to a depth of five inches, 

 leveled with a toothed harrow June 6, rolled June 7, lightly harrowed 

 to a depth of two inches the same day, planted, and finally rolled after 

 planting. Plot 10 was treated in like manner except that it was disked 

 but twice, and Plot 11 diitered only in the fact that it was disked but 

 once. Eighty-five per cent of the ants' nests in these plots were com- 

 pletely turned out by the six-inch plowing and the other 15 per cent 

 were split by the plow, a part of each nest being left undisturbed in 

 the bottom of the furrow. Fifty nests were marked in each plot as it 

 was plowed, so that they could be identified later when the field was 

 disked. 



At the first disking 45 per cent of these 150 nests, containing an 

 average of 21 ants and 2 larv?s each, were found inhabited, the re- 

 maining 55 per cent of the ant colonies having already disappeared. 

 This observation indicates the efifect of the plowing merely in dis- 

 persing the ants and breaking up their nests. Of the hundred marked 

 nests in plots 9 and 10, 30 per cent were still inhabited at the second 

 disking, with an average of 12 ants and no larvae in each, 70 per cent 

 of the colonies being now broken up by the plowing and a single disking. 



The three plots of this June planting encountered much better 

 weather than those of the regular planting in early May. and the stand 



