Missouri Cotton News
SEPTEMBER 1999

In 1997 we initiated a deep plowing study using a paratill plow. The paratill shank enters the row six inches to one side and the tip is bent to one side so that it is directly under the drill. This prevents seed from being planted in the shank entry channel and being sucked deeper into the soil when it rains. However, a cotton picker will try to follow the entry channel if the field is picked while it is wet. Therefore, it is very important that the entry channels are on rows not used by the cotton picker. This tillage operation requires a high horsepower tractor and costs average around thirteen dollars per acre.

Our deep tillage studies showed 134 pounds or 17 percent yield increase in 1997. In the same field in 1998, we had 57 pounds or 8 percent yield increase. Test plots were farmed using a stale seedbed in a reduced till situation. Deep plowing was conducted in the spring of each year. In another field in 1998, reduced tillage in no-till, reduced tillage, and conventional tillage was evaluated. An increase of 184 pounds was discovered in the no-till due to the deep tillage. The reduced tillage showed 128 pound increase in lint yield. The conventional tillage showed 191 pound increase. These results show that deep tillage is very profitable on a silt loam soil. Some producers say that they have had success deep tilling sand and clay soils, however, on clay I could see having problems with very wet soil.

We noticed that during the summer in all the years (including this year) that the deep tilled plots did not stress as much for water as the non deep tilled plots. We have not evaluated the timing of deep tilling but the dry soil in the fall should fracture much more than deep tilling wet soil in the spring. We are now trying to determine if deep tilling is needed every year. Every second or third year may be adequate.

Wednesday, September 15, 1999 the University of Missouri / Delta Center will host the 1999 Variety Trials Field Day at the Clarkton and Sikeston locations.

Meet at Clarkton at 9:00 a.m. in the field. Then proceed to Sikeston, meeting in the field at 11:00 a.m. Lunch on your own.

Clarkton: Proceed north on highway 25 for 2 miles. At the University of Missouri sign on the right turn west (left) on the gravel road instead of going the University farm. Proceed west for 1.2 miles and turn south (left) on a gravel road. Proceed south for 0.5 miles and turn east (left) on a field road for 0.3 miles. Turn north (left) on a field road and proceed 0.2 miles. The trial is on the left.

Sikeston: Proceed north on U.S. 61 from I-55 at the Kewanee exit and go 3.9 miles past highway H. Turn west (left) at the cream colored steel barn beside the white house with a grey roof and proceed west 0.5 miles on a field road. The yield trial is on the left.