The petroleum consumption cycle of the American Landscape
Over the past fifty years Americans have grown accustom to purchasing goods, using them, and trowing them away. We have also become accustom to the flow of goods and services through our homes. Food, detergents, and paper products are all products we use, then throw away. Our landscapes have become that way too. Most of us don't realize it because the work is done by others who come and quietly do the job of making our urban environment beautiful.
Our homes have become little factories that take in goods and materials, process them, then export a product in the form of waste.
Remember this image because we will look at that a little later. Many of us have begun to look closely at how we live and find ways to stop purchasing goods that produce waste and pollution. Your landscape needs attention too. Every aspect of traditional landscape maintenance requires fossil fuels to complete. As chemical fertilizers are applied, new growth is pushed from the plants. Then gas or diesel is burned to cut back the grass and shrubs. The clippings are like the product that is hauled away to the landfill.
Here's the point. Natural, free, abundant nitrogen is available all around you. Nitrogen is the element in artificial fertilizers that gets the most attention. It boosts growth of green shoots and leaves and gives a nice green color. It is applied in the spring to fill in dead spots from winter and give a lush appearance. Phosphorous and Potassium are also key elements in artificial fertilizers. They regulate flowering and promote stress resistance. For more general information about fertilizer visit wikipedia - fertilizers.
We will focus on Nitrogen for this discussion due to it's ability to leech out of the root zone and cause pollution, the amount of energy that is used to produce it, and finally the fact that it can be manufactured right in your soil today from the air.
There are five landscape practices that make up the bulk of activity on any property.
1. Irrigation
2. Fertilization
3. Pest Control
4. Mowing
5. Pruning
The order is very important. Irrigation and fertilization are the two key factors that influence most everything else. By closely regulating the quantity and source of the fertilizers, while properly maintaining irrigation levels, you can reduce pesticides, mowing time, and pruning.
It's a simple fact: the more food and energy you give to the plants, the bigger they will get. The fact is that plants have evolved to survive on very little nutrients. In fact we already know the philosophy of choosing native or adapted plants that don't need much to grow. With the practice of the hybrid landscape, a combination of 20% exotic or imported plants and 80% native or adapted plants, a very nice landscape with a traditional look can be achieved. Yet the grass still has to be mowed. Trees, shrubs, and flowers still have to look nice.
So how do we do this with the minimal amount of materials coming in and going out of our home landscape?
5% of the worlds natural gas is used to produce artificial nitrogen fertilizers.
In an earlier post I discussed at length how to manage your irrigation system to save water and promote healthy, deeper roots. This will help your landscape with nutrient uptake as well. Fertilization and irrigation are linked in another way too. Pollution. Any fertilizer nutrients that are not used by the plant are lost to the environment. These can pollute streams and lakes and cause toxins to build up in well water. Another issue is that 5% of the worlds natural gas goes to the production of artificial fertilizers. Reduce fertilizer use and you reduce the burning of fossil fuels.
http://en.wikipedia.org/wiki/Fertilizers is a good link for more information on fertilizers and their effects. http://www.cleanairgardening.com/ is a great source for natural lawn and garden products including fertilizers, soil microbial additives, and composting products.
Fertilizers do not make soil fertile.
What is soil fertility? Many people get confused about this. Fertilizers do not make soil fertile. Fertilizers are like vitamin supplements. You can't make a sick, diseased, malnourished person healthy with vitamins. Fertility is the soils ability to hold the nutrients in fertilizers when applied. When thinking of irrigation we use the image of a sponge. The bigger the sponge, the more water it can hold. That's obvious. The sponge image is good for fertility too. Think of it this way.
Soil particles are like tiny magnets with a positive charge. Nitrogen atoms have a negative charge. Some soil particles have a strong attraction to nutrient molecules like nitrogen and potassium. Others have weaker attraction so they cannot hold on to the molecule for very long. If the root does not take the molecule in fast enough then water will carry the molecule down through the soil profile into the water supply. The soil particles with the bigger charge + grabs the nitrogen molecule N faster and holds it stronger.
It's like a sponge with tiny little holes will hold more water when you lift it out of the bucket. A sponge that has big holes will let the water flow down into the bucket faster. Finer soil particles like clay will hold water and nutrients longer than courser soils like sand.
In these illustrations water droplets carry nitrogen atoms down through the soil profile. The larger gaps between the soil particles allow the water to flow past the particles and not release the nitrogen atoms N.
The smaller soil particles have smaller spaces between them and together have a stronger magnetic charge. They enable the root to take the nitrogen N up to the plant leaves.
Most of the time the location of the soil in the environment is the main factor to soil fertility. We have all heard the term "fertile bottom land". This refers to the process by which erosion by water transports soil, minerals, and other matter from high mountains to low valleys where it collects and is deposited. These areas are good for farming because the soils are fertile. They can hold molecules for a long time. The particles are smaller and have large amounts of minerals washed down from the rocks of the mountains. These minerals add magnetic charge to the soils. In fact, they can hold natural sources of nutrients that have arrived over time so no additional nutrients are needed. This is true in the middle of the United States. The fertility of that land is legendary. Soils in Florida are almost all sand. Sandy soil particles are bigger and have weak magnetic attractions so water and fertilizers will move quickly through the soil profile.
So how do you find out what kind of soil you have in your landscape?
One way is to take soil samples and send it to your local agricultural extension agent. This is a group of people that work with local universities to provide information and services to the public about agricultural issues. They will produce a detailed report about your soils fertility and nutrient levels.
http://en.wikipedia.org/wiki/Soils can provide more detailed information about soils.
Soils lacking in fertility can be improved.
For this discussion we will focus on how to improve soils that are lacking in nutrient holding capacity, and organic matter. It's hard to improve the existing soils in your yard without replacement or major tilling and disruption. But once you get the PH balanced and the moisture levels at optimum levels you can encourage the growth and development of your soils natural microbes, fungi, and microscopic worms. These organisms are the building blocks of healthy soils. There are many sources to buy organic fertilizers. The trick is to grow your soils own microbial populations.
These organisms fall into two basic categories,
Bacteria - Processing, or fixation, is necessary to convert gaseous nitrogen into forms usable by living organisms. Some fixation occurs in lightning strikes, but most fixation is done by free-living or symbiotic bacteria. (From Wikipedia.)
Fungi. - A mycorrhiza (Greek for fungus roots coined by Frank, 1885[1]; typically seen in the plural forms mycorrhizae or mycorrhizas) is a symbiotic (occasionally weakly pathogenic) association between a fungus and the roots of a plant.[2] In a mycorrhizal association the fungus may colonize the roots of a host plant either intracellularly or extracellularly. It is an important part of soil life. (From Wikipedia)
These two organisms are what will help you apply less artificial fertilizers because they will produce natural nutrients from the air. As stated above it's called nitrogen fixation (wikipedia link). Certain bacteria can take nitrogen from the air that is not available to plants, and change its from so it can be taken up from the soil in plant roots. Certain fungi attach to plant roots and create a symbiotic relationship where the fungi help in the uptake of nutrients from the soil and receive a little food from the plant to survive. And as another bonus, these same microbial colonies help break down the old dead and dying grass leaves called thatch. This is significant because faster decomposition of thatch also increases the ability to leave clippings on the ground naturally. The process of getting nitrogen from the air down to plant roots in an available form is complex and fascinating.
Your landscape is a scary place.
Large herds of grazers feed on grass as the predators roam in search of prey. Sounds a lot like the African plains, only much smaller. Yet, the life inside your yard is just as savage.
Bacteria feed on dying grass blades absorbing the nutrients into their bodies. Some bacteria convert nitrogen from the air into their bodies, Microscopic organisms called protozoa eat the bacteria. As they feed on bacteria they release Nitrogen to plant roots. Microscopic worms called nematodes feed on the protozoa and release more nitrogen to the plant roots in the surrounding soil.
Each predator in the food chain needs less nitrogen than is contained in the prey item.
Thus the predator releases the excess nitrogen as waste. So by increasing the numbers of soil organisms and letting them feed on each other in a sort of huge gladiator arena, natural nitrogen will be released into the soil for plant up-take. The greatest thing is that once this environment is created it will continue for as long as the soils are not contaminated or applied with pesticides that kill key parts of this food chain. With artificial fertilizers the process is repeated every year. These natural processes act on their own and need little or no additional support once they are established. We know nitrogen is critical for plant growth and a deep green color. It's also the nutrient that is most likely to be lost to the ground water if it is over applied. These natural processes will boost nitrogen levels naturally for free.
Arthropods are the largest of the predators in the food chain.
They include insects familiar to us like beetles, millipedes, and sow bugs. They are also very small, almost microscopic. These organisms help by shredding dead leaves as they feed. This process breaks down dead leaves so the bacteria can feed more easily. Let us look at the 'shredder' arthropods a bit more closely. The act of shredding organic matter is crucial to start the process of nutrient release we spoke of earlier. If you spray your lawn regularly with insecticides these organisms are killed and the dead leaves build up and take much longer to break down. As a result, the dead organic matter builds up and needs to be dealt with. If it's your lawn, then power thatching and core aeration is performed. This burns gas and can cost a lot of money.
Earthworms - The ultimate shredder.
Earthworms are the most famous of the soil organisms. Worm castings have been used for fertilizers for a long time. As they feed earthworms take dead organic matter underground to feed and leave nutrient rich waste as they move about. These organisms can be killed by pesticides as well. Further reducing the soils ability to produce it's own nutrients. So go to a bait shop and buy a few carton of earthworms and the smaller red worms and release them into you lawn and landscape. They also are very beneficial to houseplants too.
Artificial fertilizers...The flaw is that it's a linear system.
Artificial fertilizers are applied because it a simple easy way to get a lawn green and growing. There is nothing wrong with that. The flaw is that it's a linear system. Meaning that materials (fertilizers, water) go in, are processed (mowed and clipped) into finish products, (clippings) then hauled off site (to the landfill). A system of feeding and growing the natural colonies of microorganisms in the soil to provide nutrients to plants will reduce or eliminate the need for artificial fertilizers. Thus making the system more circular. Determining if your soils are high in microbes is difficult for the average homeowner. knowing where the soils in your yard came from is difficult, if not impossible. Yet their are a few thing you can do to determine the best course of action to make your soils healthier.
Growing active, healthy soils involves four things:
1. Inoculating soils with new bacteria and fungi
2. Monitoring PH levels to maintain them at 7.0
3. Adding carbohydrates (sugar or molasses) to encourage faster growth of bacteria.
4. Monitor moisture levels (see post - Save Water in Five Steps
STEP 1 Soil Innoculation
Soils in new landscapes that have been imported may be low in natural soil microbes. You can add these organisms with commercially available products. (cleanairgardening.com) You can also use your own compost pile if you have one. By spreading your aged compost on your lawn the native microbes will take hold and grow. Let me say one thing about buying soil microbes from a commercial supplier. Like plant communities, soil microbes are different genetically from region to region. Commercial products are fine but any naturally occurring populations will be better. As I stated above, changing your soils is hard if not impossible. Yet a layer of active, healthy soils can be achieved with a little patience and a few afternoons a month. It basically breaks down to two things. * Building a compost bin to catch drainage. * Applying the drain water to the lawn. A simple compost bin can be made out of strong wire fencing, a pallet, four cinder blocks, and a refridgerator pan. The wire fence alows air to circulate freely. The pallet will elevate the pile above the tray. Next, running, the water from a hose will soak through the compost pile and wash all the microbes, arthropods, and nematodes down into the tray. This example was made from recycled metal fence posts, cattle wire, and a cooking tray. The tarp is to hold moisture due to the arid climate where this is located. The wood at the bottom has a hole to funnel water into the catch tray. All made from recycled materials At this point you can take that liquid and add water, and molassis, then ferment it to make larger amounts of compost tea for larger projects. I feel their is an easier way to do this that skips a few steps by alowing the fermentation to occur in the lawn. It involves using whats called a 'hose end applicator'. The excess water is collected in the tray. then it is filtered to remove large debris like leaves, twigs, etc. This water has billions of good soil microbes. Mix it in the hose end applicator with the right amount of molassis. Then turn on the hose and spray on your lawn and landscape. A Hose End Applicator is easy to get at any hardware store. It uses the water from your hose to mix small amounts of any material in the applicator, then sprays out the mixture with the hose water to wherever it is needed. Instead of fermenting the 'Tea' in a barrel or large bucket, the concentrate from the compost pile is applied directly to the yard with the molases. The population growth takes place in the soil. Remember to run your irrigation for about 15 minutes after applying the compost tea. These are handy tools to have on hand. It will allow you to apply small amounts of compost teas to the yard quickly and effectively.
Step 2 Soil Acidity
Soil PH is very important to plant health as well. PH is a chemical property of the soil that effects how nutrients are available to living organisms. Many people change their soils PH by adding lime or sulfur to raise or lower PH. This is an area that will be easier with the help of your local agricultural extension office I spoke about earlier. For more detailed information on PH see Wikipedia. http://en.wikipedia.org/wiki/Soil_ph
Step 3 Adding Sugars
Adding sugars to soil may sound a little strange. But the science is solid. When plants carry out photosynthesis they create sugar. This is the food that animals eat. It's also the food source that soil microbes are after as well. By boosting the sugars present in soils, microbial populations are boosted. This is beneficial by speeding the processes that break down the dead and dying leaves, grass blades, etc. As this occurs organic matter is added to the soil naturally. Let me say one word of caution about applying sugars to your lawn. Of too much sugar is applied, then the bacteria population explodes. As this happens the bacteria consume the soils available nitrogen to grow and reproduce. This can rob the grass of nitrogen, and cause yellowing of the turf. It is temporary. As the bacteria die off because the sugars are used up, the nitrogen stored in their bodies is released back to the lawn and the green color will com back. A good rule of thumb is this:
* 3-5 oz. of molassis per 1000 sq.ft. ( 20'x50')
Step 4 Monitoring Moisture
Moisture levels are very important also. Soil microbial populations need water just like plants do. See my post Save Water in Five Steps for more detailed information on water management.
Throughout our history we have tried to replace nature with machines, chemistry, and man made biology. Then it seems each time we find out that Nature has the same thing that works on it's own, with little support needed other than to be left alone to carry out it's natural processes. Now with climate change becoming more than a theory, we need to look to ways to use the natural processes all around us to live simpler, better lives. Hopefully the use of fossil fuel based artificial fertilizers can be eliminated or at least reduced as your landscape soils grow and become more active, healthy and alive.
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