GETTING A JUMP ON WEEDS

Randy Henke

Sawvyer, North Dakota

Achieving a quick emerging crop starts with a quality seeding unit. Some key elements to 100k for in a drill include:

Good depth control: One of zero tills strengths is that under normal conditions there will be moisture right to the surface. A crop planted at. a uniform 1 " depth goes into warmer soil and emerges much quicker than it does from 2".

Seed soil contact: Whatever type of opener you choose, it needs to provide good seed soil contact. Any type of hairpinning (pressing chaff or straw into the slot) or bunching can slow or stop germination.

Press Wheels: Some type of press wheel that is adjustable and does a good job of shedding mud is a good idea. You're more likely to be planting under too wet conditions rather than too dry.

Low soil disturbance is an area that from the beginning, I could tell had value supressing annual weeds. I think these newer generation very low disturbance drills may significantly increase this suppression. In my area of the world my best guess as to the value of this annual weed suppression is 6O-7O%. It can vary anywhere from 0-100% depending on the year and the weed. Every weed seed that doesn't germinate is one less that I need to control with herbicides and in this age of herbicide resistance this takes on added value.

Fertilizer placement can also be used to put weeds at a disadvantage. Any type of a system that places fertilizer between the rows, directly to the side, or below the row can put weeds at a substantial disadvantage. Maybe low soil disturbance can be worked into this. Ammonium nitrate (or spoke wheel applicators) have been successfully applied to 4 leaf wheat in recent years. The idea is to be adding the bulk of the N at about the same time the herbicide treatment is killing the weeds.

Careful planning of crop rotations can be used to put crops at an advantage. Some examples include:

Planting barley early into canola, peas or flax residue. These are low residue, dark colored residue crops which will enhance early planting to get the barley ahead of the weeds.

Planting lentils, a crop which is a poor competitor and dependent on herbicides into winter wheat stubble which is a excellent competitor that needs few herbicides and generally leaves nice clean stubble.

Some other closing thoughts.

Row spacing: The narrower you can make your rows, the quicker crops like sunflower, pinto beans, or navy beans can close the canopy making them less reliant on herbicides.

Fall burndown: This can eliminate the winter annuals right from the start. and greatly reduce competition from perennials like Canada thistle.

Residue management: Chaff rows tend to concentrate volunteer grain and weed seeds in rows behind the combine. This can also make cooler soil temperatures in this area reducing crop vigour.

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