Soil Test Experiment in 1918. 55 



would make the supply of plant food uneven. But as this 

 field was a long distance from the buildings and until the Sta- 

 tion took possession separated from the rest of the farm by a 

 run with a very had road, it is not likely that great amounts of 

 farm manure had been taken to this field. 



In Series A, with potatoes in 1917, the plots in the ninth 

 row (19, 29, 39, and 49) gave low yields. Plot 19 is without 

 nitrogen in the fertilizer. And with ammonia as the limiting 

 factor a small yield would be expected. Plot 29 had a special 

 mixture of 5-8-7 formula. Its yield was about 20 hundred- 

 weight below what one would have expected. Plot 39 was 

 also without ammonia in the fertilizer. During the whole sea- 

 son of 1917 the plants on plot 39 had a discouraged look and 

 the yield was even lower than that on the check plot 49. And 

 the yield on this check plot was about 20 hundredweight be- 

 low the next lowest check plot and nearly 30 hundredweight 

 below the average yield for the check plots. 



With 2 crops, one of potatoes and one of oats, on the 

 plots on Series A and with nitrogen the limiting factor in both 

 crops on this land, it is possible to draw some inferences as 

 to the uniformity of the soil on the different plots from these 

 yields. 



As the plots are numbered in rows from east t© west by a 

 row and plot number, thus plot 11, means row 1, plot 1, it 

 makes it that from south to north all the plots in which the 

 figure 1 is the second figure in the plot number are in one row 

 or tier, and all the plots with 2 the second figure are in the 

 next tier etc., (see diagram of field page 41). Hence the plots 

 • can be considered in a south to north relation as well as an east 

 to west. Plots treated with ammonia, phosphoric acid and 

 potash, and check plots and no ammonia plots occur in nearly 

 every south and north tier. The yields from the fertilized 

 plots and the check plots and those without ammonia in the 

 mixture are tabulated by tiers of plots and again by groups of 

 3 tiers in the table that follows. 



The field slopes gradually from the east to the west. The 

 plots are numbered from east to west. Therefore the groups 

 of plots in which the second figure is 1 is at the east side of 

 the field 'and they progress toward the west until the last group 

 with 9 as the second figure is reached. It will be noted that 



