If you find
Bare ground fills with weeds
OR
At certain times of the year pests get a foot-hold on a key crop
OR
If you don’t grow something in a particular spot, nature does; and it is usually something you don’t want there
Then,
Filling niches so that undesirable species can’t occupy them should reduce the problem.
Farming and grazing are about providing niches for the species you want. At the same time, you need to fill niches to make them unavailable for species you don’t want and the best way to do this is to fill every niche with desirable plants, animals or microbes.
The next best way is to block the niche, such as by using mulch to block weeds from colonizing bare ground.
A niche is a place to live and it applies to a pest and a crop. A niche is more than just the place where an organism fits physically. It is also the organism’s function or role in the community of plants, animals and other organisms.
(An organism is a living individual thing such as a plant, an animal or a microbe. Each organism is made up of various parts that depend on each other and work together.)
Niche comes from the Latin word nidus meaning nest and also means a little nook in a wall where people put ornaments etc.
How you manage your niches determines what pest problems you have and it sets your yield. If you have significant problems with pests, it is most likely that your management of niches is out of line with what you are trying to achieve.
Sometimes the easiest way to reduce the problem you’re having with pests is to change the way you manage niches. Many of the problems of modern agriculture come down to niche problems:
- Where there is a weed there is a niche that is better for weeds than for crops.
- Where pests damage plants, animals or microbes, the niche is more suited to the pests than to the beneficial organisms.
So, changing the niche conditions to suit you instead of the pest can move the balance back towards profit.
Often this will involve only simple and easy changes. But sometimes this requires a major shift in your farming, because your main crop and the way you manage it may be providing ideal conditions for your worst pest.
Graziers and farmers aim to provide good niches for the organisms they want (cattle, wheat, apples, sheep, broccoli etc).
At the same time they want to make it difficult for any undesirables (weeds, insect pests, diseases, parasites etc) to find or establish their own niches. Often this involves filling a niche with a desirable species so that the niche is not available for an undesirable species.
You may find two species in one physical spot but they will not stay in the same niche for long. they will generally need to exploit different things in that environment.
If they were competing in the same niche, one would get squeezed out by the other that had some slight Advantage under those conditions. Perhaps one would not survive well enough to reproduce as successfully or its offspring would not establish as successfully in competition with the offspring of the other. For example
- Unless you keep pushing the balance in favor of your crops, a weed will steadily take over an area. This is because that weed has a niche there. Unless your crop, livestock or pasture is native to that area, it only has a niche while you provide it
- Two species that seem to live in the same niche will have different diets, functions or relationships to their environment. They may:
- eat different things although they both live in the same place. Or
- eat the same things — such as two types of blood suckers in different places — one living inside an animal, the other on the animal’s skin.
An earthworm occupies a particular position in the soil and carries out certain functions in the soil. It is dependent on many other organisms, many sources of food and on a variety of soil conditions to survive, let alone thrive in that niche.
If another organism is a more successful competitor for the earthworm’s food supply then the earthworm may need to move sideways to find food, may go dormant until things improve or it may die.
That’s the food side of niche competition, but other conditions also affect the worm:
- Compaction by animals or machinery
- the soil becoming too acid
- soil getting too hot
- the soil drying out
- the soil becoming waterlogged for too long
- the weather becoming too cold
- the soil becoming too saline
- overcrowding leading to a fall in nutrients that brings on starvation
- and so on.
As a result, the earthworm is at the mercy of anything that destroys or takes over its niche.
Spraying weeds out creates areas of bare ground ripe for colonization by other organisms, most likely more weeds and particularly weeds resistant to the chemical you just used.
Full ground cover is a key tactic in reducing weed problems because it is a simple way to have as many niches filled as possible to reduce the chances of weed establishment.
Where the niches can’t be filled with living plants, dead plant material in the form of mulch or straw can block access to the niches so undesirable plants can’t get established.
Weeds establish because you have not filled every niche from one side of your property to the other, year-round. For example, a crop does not use all the space and water that is available, particularly when an annual crop is just getting started as a seedling or when a perennial crop is dormant, such as over the coldest part of the winter or the hottest part of summer, depending on which is worse in your area.
That leaves room for a weed.
When you have plants year-round, you have plants guarding every scrap of the soil from weed invasion. If there is a gap for part of the year even in just a small area, there is a niche for even just one weed to fill, so it is important to maintain full ground cover year-round if possible.
Pest species are opportunistic and well adapted. Rarely are productive species opportunistic or well adapted and that is why we go to so much trouble to provide ideal conditions for them.
Weeds often establish in niches such as bare ground because they are better adapted to it than most crop and pasture plants are.
Because Nature fills any vacuum, if you leave an empty space undefended you leave it open for invasion. Nature will not fill the gap with a crop plant nor with a pasture plant. Instead it will fill it with whatever is there or arrives there and can survive there.
Unfortunately that is often a weed.
But at the same time, Nature fills any vacuum is a key farm management tool.
How?
Well, if you manage the situation well, natural processes will fill the vacuum with something you want there, rather than something you don’t. The trick is to find species that can colonize any niches and that either benefit you directly by being productive or indirectly by keeping out an unproductive species.
An example of this was when I was chipping out my worst weed with a mattock and putting the plant into a sack that I would later empty into a bin on the back of the farm truck for composting at the farmhouse garden.
I dropped a handful of seed into the gap left by the plant.
But when I chipped out this same weed at a time when the annual pasture plants were just getting rolling, I didn’t bother with the seeds, the pasture usually filled the gap for me — Nature filled this vacuum with species I wanted there because the time and circumstances suited my species.
A crop field often has only crop plants and there are many spaces between the plants plus larger spaces where crop plants failed to establish successfully. These spaces are ideal for weeds.
A crop doesn’t use all the nutrients, moisture and light available to it. These resources are available for other plants that often turn out to be weeds.
When plants cover every scrap of ground from one boundary to the other throughout the year, they guard every bit of the soil from weed invasion. Whenever there is a gap for part of the year in just a small area, weeds can take that spot.
So, in summary, if a space is unoccupied, something will eventually make it their home because Nature fills any vacuum and if you want a niche filled with your desirable species, you need to provide conditions that foster those species.
Note, for more about a Filled niche in the market, see Market niche because if any single thing causes low profitability, it is low returns from the market and one part of fixing that is to find and fill your niche in the market.