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by John Cloud


Everybody complains about the weed populations in their fields, but not many people seem able to do anything about them. One of the subjects I get asked about most frequently is weed control.

I have found that most success with weeds has to do with three factors: the weather; the type and condition of the soil; and the farmer. These unite in an infinite number of combinations to provide a seemingly infinite number of field conditions. These field conditions are reflected in the types and quantity of weeds you have in the field.

What can be done with these to get a little control in your life?

The first factor, weather, we can’t do much about. We can plant hedgerows and control erosion to minimize the impact of weather. The planting of hedgerows helps to reduce the "greenhouse effect" which is responsible for destabilizing our weather patterns. Additionally, hedgerows help prevent soil loss from wind erosion. The warmer our winters become, the less snow cover we have to help hold the soil in place. If you are fall ploughing and not winter cover cropping, you are asking for wind erosion.

The second factor which determines your weed populations is your soil type. Even though you don’t have control over the type of soil that is on your farm, you are responsible for that soil’s condition. A narrow crop rotation of only a few different crops will yield poor soil conditions. Additionally, crops which are planted and harvested at the same time and/or have similar root structures will generate identical conditions, thus giving you the same soil structure and weed populations. Corn and soybeans are examples of this similarity. Your rotation must stagger crops which have varying root structure (size and depth of growth) as well as perform various methods of stress on the weed population (choking crops, allelopathic crops, cultivated crops). Organic matter in the soil will continue to change the soil conditions. As the organic matter increases, the weed types will begin to change. This is in part the result of a change in the structure of your soil as well as of different nutrients being available. For instance, if you have less than 5% organic matter in your soil, the phosphate may be bonding to your soil’s calcium and not be readily available to your crop. Don’t just add rock phosphate; also add organic matter in the form of winter cover crop plough-downs. You can’t change your soil type but you can change your soil’s condition.

The third and most important factor for controlling weeds is YOU. You are the one responsible for performing well-timed cultivation when the weeds are at their most vulnerable stage. You are responsible for planning rotations to include winter cover crops which increase competition on twitch and other grasses. You are responsible for alternating choking crops with cultivated and allelopathic crops. You are responsible for doing soil tests which insure your soils against imbalances of N, P, K, pH and OM. You are responsible for developing weed maps of your farm and comparing them to your soil tests. You are responsible for keeping records of new techniques you implemented and of successes and failures experienced in each field. Just simple records on your farm map will help you see where you have been successful over the years. These records also prevent you from rerunning ideas that you tried a few years ago. The reason many of us forget that we tried a new technique a few years ago is because it didn’t work and we forgot about it. Keeping these simple records of your crops and field work will help you get a little control in your life.



Copyright 1995. John Cloud

Reprinted with permission. All rights reserved.

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