The registration period is from 04/18/2018 3:00 pm to 05/25/2018 5:00 pm
Reading Weeds, An Introduction To Plant Indicators - Details
Dates:  05/27/2018 - 05/27/2018
Times:  9:30 am - 5:30 pm
Location:   Solar Living Center, Hopland, CA
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            Weeds, those pests in your fields, are going to become your most valuable tool for testing your soil.

            Most fields have weeds. They are there day and night, rain or shine, experiencing the forces that shape plant growth. Weeds can be used as dynamic and sensitive indicators of growing conditions in a field.

            For millennia, farmers and ranchers have been observing weeds and making decisions based on their observations. Acquiring this detailed information has been a long and arduous task. Now specific weed information is available in a database to enable everyone to make use of this skill. High-tech tools now give modern farmers, ranchers, and gardeners information that formerly took a lifetime to acquire. This is the basis for the reference section of Reading Weeds.

            Let's consider the use of plant indicators in modern agriculture. A chemical soil test is a snapshot of what is happening at that moment in the soil. From this you can infer how the crop plant might react. This is an educated guess, based on the factors of a chemical reaction and comparison to similar situations, but still a guess.

            In contrast a weed seedling has survived at least several weeks of the nearby conditions, and its development tells much about those conditions. The ability to translate its message is especially valuable because it measures directly the field's ability to grow plants. This, of course, is the soil quality you most want to know.

            Chemical laboratory techniques and field assays are in no sense competitive, but closely complement one another. In addition to your other conventional methods of field evaluation, weed indicators give you different information. Also whenever you are in your field, you can make observations.

            Surveys of weed seeds have shown ranges of 10,000 to 50,000 seeds per square foot of soil in a field. In most fields these don't all sprout at once. Since a seed waits to germinate until conditions are right, when you see a weed seedling you know that these requirements were met at least for a short time.

            To germinate, seeds may require standing water, freezing, fire, fermentation, a lot of oxygen, or other factors. Knowing this helps you predict a crop's performance. After the plant is up, its growth shows that its growing conditions are also being met, giving you that much more information about the soil.

             Clements, a plant ecologist, said that "Every plant is a measure of the conditions under which it grows, an index of soil and climate, an indicator of the behavior of other plants and of animals in the same spot."


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