- 4,-


three or four times during a single year where conventional tillage is used. This
is why most growers have planters attached directly behind the subsoiler chisel in
order to avoid recompaction of the soil between the subsoiling and planting operation.
Minimum tillage provides a way to avoid recompaction of soil in the subsoil slit be-
tween crops since the location of the rows from the previous crop are visible during
the planting operation. Therefore, the tractor operator can run the tractor wheels
between rows and plant directly over the subsoiler slit made for the previous crop.
Perhaps as a result of. this practice the subsoiling operation would only be necessary
every other year. Thus, a significant savings of energy would be accomplished.


 PENETROMETER RESISTANCE BARS
0 10 20 30 40


LI
U->
* 30
-S
0


PENETROMETER RESISTANCE BARS
 10 20 30


 SUBSOILED
 FOLLOWED BY
 TRACTOR TIRE

TRIP
TRIPS
TRIPS


Penetrometer resistance
before subsoiling and in
the subsoiler crevice be-
fore and after four trips
with a disc harrow.


Figure 4.


Effect of a tractor tire on
recompaction of soil in the
subsoiler crevice.


Figure 3.