This is the VOA Special English Agriculture Report.
Weeds compete with plantings for water and nutrients. So farmers and
gardeners may have good reason to hate them. But weeds can also bring pretty
flowers and wild beauty to places lacking either. British nature writer Richard
Mabey offers support for weeds in his new book. The title says it all: "Weeds:
In Defense of Nature's Most Unloved Plants."
But when exactly is a plant considered a weed? Experts at Penn State
University say the answer is simple: when the undesirable qualities outweigh the
good qualities.
A crop plant generally produces several hundred seeds. But a weed plant can
produce tens or even hundreds of thousands of seeds. And if seeds get buried,
they may survive for many years underground.
Eradicating weeds means that you have to remove all the seeds and roots so
the plants will not grow back. But birds or the wind can reintroduce them to the
land.
A more common way to deal with weeds is to control them enough so that the
land can be used for planting. Experts advise using two or more control methods
to deal with weeds.
Chemical weed killers or natural treatments like corn gluten can suppress
weed growth. But so can dense planting. Bill Curran is a professor of weed
science at Penn State. He says a dense, competitive crop that quickly shades the
soil from the sun will help reduce weed growth.
Other controls include turning over the soil, pulling the weeds or covering
them with mulch made of wood, garden waste or other material.
But even mulch has its limits. Natural resource specialists point out that
weeds can be transported in mulch. This is also true of soil, grain, hay and
animals.
Yet animals like sheep or goats eat weeds, so they can provide a biological
control. Insects and other organisms can also act as biological controls.
Preventing the spread of weeds is an important part of weed management. Farm
vehicles should be kept out of areas with weeds. If that is not possible, then
clean off the equipment and your shoes when leaving.
Some people burn weeds or bury them deep in the ground or make them into
mulch.
Professor Curran says another way to make use of weeds is to compost them.
The process of making organically rich compost produces heat. This heat kills
many, though not all, weed seeds. The same is true for seeds that pass through
animals that graze on weeds.
And that's the VOA Special English Agriculture Report, written by Jerilyn
Watson. I'm Jim Tedder.
