PLANTING 37 
with the first plowing. By plowing with high arch cultivators 
after the corn is from three to seven feet high, all weeds 
are killed after the ground is shaded. 
Where furrow openers are used, the depth of the furrow 
is regulated by the lever which raises or lowers the runners, 
but in order to vary the depth of planting it is necessary to 
raise or lower the discs on the planter shoes. In our own 
practice we set the discs to throw out a furrow of sufficient 
depth to remove all weed sprouts and dry dirt from the 
furrow. To accomplish this requires a furrow of from two 
to four inches deep, depending on the dryness of the seed 
bed. Those who have used furrow openers know that, being 
a perfect gauge, their use insures a uniform depth of 
planting. 
Although the corn is planted from three to five inches 
below the surface of the field, it is not covered by much 
more than an inch of dirt. It is, however, all moist soil, 
since the dry dirt has all been thrown out by the dises. 
Some plant in a very deep furrow, but we do not recom- 
mend this, since the sub-surface is often too cold for quick 
germination. After a hard rain, water may stand in the 
furrows if they are very deep. 
There are some soils and conditions where the use of the 
furrow openers would not prove practical. On low, wet land 
where the water level is near the surface, the furrows might 
stand full of water too long after heavy rains. The use of 
furrow openers has not proved a success on very hilly land, 
since the rainfall will gather in the furrows and wash out 
the seed. 
While we have mentioned these objections to the use of 
furrow openers, the reader should bear in mind the fact 
that the first plowing fills up the furrow and leaves the ground 
level. 
NOTE: More will be said about furrow openers in the next chapter. 
