Trees reduce surface winds by 80%
A properly designed shelter-belt or the newer eco-belt will reduce surface winds up to 80% which will greatly reduce wind erosion, heating and cooling costs, and will reduce crop stresses due to winds.
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In winter this wind speed reduction is really noticeable when walking from an exposed location to a sheltered one, you will notice how much warmer the sheltered location feels because of the reduction in wind speeds. Now you might say that to get the benefits in winter you need evergreens and they take forever to get large enough to fill in! Well not so! A well designed deciduous shelter-belt can gain just as much benefit from wind speed reductions as an evergreen one!
What sort of wind speed reduction can I expect?
The amount of reduction is highly dependant on the design and type of trees but even a 10 foot wide row of Caragana and Poplar like we have next to our tree field will result in a 50% wind speed reduction in winter.
We will go over the designing later in the series but for now just know the benefits are large even with a small shelter-belt
How do reduced wind speeds benefit my crops?
Reduced wind speeds are beneficial for your crops for several reasons. First, strong winds can of course flatten crops when strong enough. We all have seen how much harder it is to harvest flattened crops and the negative effect it has on growth if they get flattened early on in their life. Second, reduced wind speed reduces evaporation losses. A strong wind can easily pull more moisture from the crop than it can replace which causes it to reduce pore openings which in turn reduces growth rates.
The largest difference though, is the creation of micro climates from reduced wind speeds. If you can capture the heat during winter sun and reduce the rate of wind heat loss with a shelter-belt, you can quickly raise your hardiness zone by a full point. Add in a south slope and you may even be able to push 2 zones higher in a well sheltered area. This is a huge boost in terms of growing season and perennial crop survival. Its the difference between only being able to grow grains like wheat and the ability to grow high value crops like lavender or other herbs.
Multiple shelter belts can increase crop yields
A study in the US revealed that multiple shelter belts spaced across a crop field can actually increase total yields! The total yields increased between 1% and 16% with an average of almost 8% increases even when factoring less acres were planted with the shelter belts!
This increase in yield was magnified when one includes that straw can be harvested more often because of the additional organic matter added by the shelter belt!
Another yield increasing factor from well designed shelter belts is the increase in natural predators, and due to including flowering shrubs an increase in pollinators will result as well!
The end result is a net increase in crops despite planting less acres (further savings in fuel, seed, and fertilizer!) and an improvement in the environment.
What about heating bills?
Household heating bills in a well sheltered area are able to be reduced by 10% by reducing the amount of heat loss caused by wind. This can quickly add up if you think about it! An average heating bill of $1200/yr can see a savings of $120 per year! That buys an extra twelve 1 gallon trees and shrubs, or as many as 60 plugs if you buy them as seedlings! I don’t know about you but I’d rather give my money to tree farms than to the heating company!
As another added bonus: If you have a wood stove in your house your shelter belt can provide additional savings though providing wood! This long standing traditional heat source feels great in winter and through using a local source you can save a bundle over buying the wood from somewhere else. As an added bonus if you have too much wood you can sell it to others providing a bit of additional income.
Also with rising carbon taxes, lets not forget that wood heat is carbon tax free (well not quite if you have a gas powered chainsaw and truck to haul it home… but with the push for electric power in future this will be reduced over time) so for every piece of wood you put into your wood stove, you are keeping money in your pocket instead of the governments pocket! This further savings can be put towards planting more trees to save even more in the future!
If a farmer adds in multiple shelter belts to improve crops like suggested above, it can also lead to a source of off season income! Firewood is in demand and there are few sources in the prairie lands that cover a lot of this province. Providing a local source of firewood would provide income and would save customers money from not having to pay to truck it in from further out! It is often stated as a rule of thumb that 5 acres of well maintained forest can heat a home through winter – do the math with how much shelter belts your farm would have and you can quickly see an income.