Science of Sustainability- How Soil Erosion Happens

Soil erosion is the enemy of anyone who works with soil.  It is a constant battle against the elements in a effort to save and improve the precious resource that is soil.  The primary erosive forces that occur in nature are wind and water and they effect soil in different and subtle ways.

Wind

There are 3 primary ways that wind can erode soil.  You have creep which is when particles that are to big to be lifted by the wind are pushed along the ground by it.  These particles tend to dislodge other ones and cause further erosion along the winds path.  

Then you have saltation which is when particles of soil are briefly suspended into the air but will drop back down to the surface of the ground.  The impact of the soil particles as they drop back to the surface causes them to breakdown into smaller particles which can be carried by the wind.

Finally we have suspension which is when particles less then .1 mm in diameter can be carried by the wind long distances.  This stage of wind erosion is one of the most visible and awe inspiring forms of it that we can experience.  The images from the Dust Bowl are the most visible example of this.

     The amount of erosion that happened during the Dust Bowl is estimated to have damaged over 80% of the High Plains region.  By 1938 over 5 inches of topsoil had been lost on 10 million acres and another 2.5 inches was lost on another 13 million acres.   

Despite all our efforts to fight soil erosion and all we have learned over the years it is still a issue we deal with today.  

Water

Water erosion is a common problem facing farmers, ranchers, roads and anything that is built on soil.  There are four types of erosion that occur from water, sheet, rill, gully and splash erosion.  

Sheet erosion is when water move across the soil surface in a smooth even layer of water.  It is not a very powerful form of erosion and will only remove a thin layer of soil.  The caveat to that is the water will remove soil from a large area and that can add up quickly when you have large areas of bare soil cropland.  

Rill erosion is the next step up on the water erosion list.  You get rill erosion when the even coverage of sheet erosion coalesces into thin streams of water that cut deeper into the soil profile.  They can create a spider web effect across a bare crop field that looks like the picture to the right.

Gully erosion is created when rills run together and slope increases which causes the water to dig down into the soil and create a wide, deep channel.  There is some confusion sometimes about when it is a rill and when it is a gully.  A good rule of thumb to follow is that when you can smooth it out easily then it's a rill if you can't then it's a gully.

Splash erosion  occurs during weather events when rain drops impact the soil and can fling soil particles up to 3 feet from the impact point.  In the center of a field this is not much of issue but it can cause erosion at the edges.

So now that I have covered the basic ways erosion happens in nature it should give you a better idea how it can happen to you.  You have to understand how erosion works so that it can be avoided when you are trying to build a sustainable life.  Erosion if not properly planned for can ruin months of work in one bad storm so it is important to know your land and the soils that are on it.  

Stay tuned for more Science of Sustainability topics

  

Science of Sustainability- How Soil is Formed

So in my last few posts I have been covering various topics in soils.  From the basic structure of soils to soil pH there is much you need to know about soils in order to successfully manage them in a sustainable fashion.  Without soil humans could not exist on this planet at all, it forms the base on which we grow our food, build our homes, and live out our lives.  But soil is not something that forms overnight.  It takes anywhere from thousands to millions of years to build even one inch of soil so it is not a resource that should be wasted or mismanaged.

There are 5 factors that contribute soil formation that take place in the natural world,

• Parent Material 
• Climate
• Landscape Position
• Living Organisms
• Time   

Parent Material

The parent material of a soil is the native rock of any location.  The soil will take on the characteristics of the parent material it was formed from.  So if you live in a area that has a limestone bedrock the soil that formed on it will be alkaline and may inhibit the growth of certain plants.  Knowing what the parent material is beneath your feet can save you a lot of time and effort when it comes to starting a garden.

Climate   

The climate and the weather patterns of the location in which a soil forms greatly impact the rate at which soil can form.  Through weathering from wind, rain and sun the parent material of a soil will slowly break into smaller and smaller particles until it becomes the sands, silts and clay's that form building blocks of soil.  Areas that have lots of rain, softer parent materials and other erosive forces will generate a thick layer of soil much quicker than a areas like the deserts, mountians or the poles.  

Landscape

Landscape affects how soils form on a smaller scale.  Even with all other factors being the same the soil that is at the bottom of the hill will be different that the soil at the top of the hill.  There will be variability in thickness, chemical composition, pH, soil texture, etc.   

The tree growing out of a rock shows this perfectly.

Living Organisms

Once there is a little soil in place organisms like mosses and lichens can begin to take root.  Once they do the roots of the plants speed the process up by cracking and breaking the parent material up further.  The cracks allow more water to penetrate into the parent material which allows it erode faster.  As more soil forms you get larger and larger plants growing in the soil that forms which accelerates the process yet again.  

Time  

Time is by far the most important factor in soil formation.  When it can take 1000 years under the most favorable conditions to form a inch of soil you need a lot of time to get something useful.  If you look at Mollisols or prairie soils they can be 2 ft or more in thickness depending on your location.  Even under good conditions that could be 20,000 years to form the soil which is considered the breadbasket of the world.  You will also have forces overtime that can actually reset soil formation like floods or glaciers which can scour away all the soil that formed forcing the process to start again.  

Sustainable Living

By knowing how soil is formed and perhaps more importantly how long it takes to form it should give you a appreciation for soil and what it is worth.  To manage the soil in a sustainable way should be the number one goal of anyone seeking to live a self sufficient lifestyle.  Soil is lost at a rate of 10 times the rate of replenishment here in the US.  If one of the most advanced and educated countries in the world can't manage our soil correctly then the rest of the world doesn't have much hope.  But through good practices and sustainable use we can stop and even reverse soil erosion if we wanted too.  But the challenges to do that are great and soil erosion will never stop completely.   

Stay tuned for more Science of Sustainability topics.        

Science of Sustainability- Jar Test for Soil Compostion

There are many methods and tools out there for figuring out what your soil it made of.  They can range from very cheap to omg expensive and unless you have a big bankroll you will want to stay away from a lot of them.

One of the most common things you will want to know about your soil is what is it made of.  All soil is made of a combination of sands, silts and clay's in various percentages.  What those percentages are is critical for determining a lot of what you do on your land.

There are a few ways you can test to figure out what soil components your soil has.  There is the soil texture triangle like I talked about in my last post or you can also use progressively smaller screens to separate the soil into its component parts.

The method I want to talk about today is the jar method.  To do this you need a large jar like one of those gallon size pickle jars, a decent sample of your soil and water.

Take your glass jar and fill it about 1/3 full of soil.  Make sure the soil you use is a representative  sample of the area you are testing.  The add enough water to fill the jar about 2/3 full.  Shake the jar until all the soil is completely mixed and suspended into the water.

Then leave the jar to sit for at least 24 hours or longer if needed to get clear water at the top of the jar.

Once all the particles of soil have settled to the bottom of the jar you should see clear bands of different soil materials. At the bottom will be the sands then the silts and the clay's will be on top of that.  By measuring how thick the bands of soil are then comparing that to the total thickness of the soil you can get a rough percentage of the soil composition.  

This test can be more accurate for a novice to perform than the texture triangle as you can use simple measurements and little math to get a accurate reading.

Stay tuned for more Science of Sustainability topics        

Science of Sustainability- Soil Texture Triangle

When building a new sustainable lifestyle you will need to become well versed in topics you have never given a thought about before.  One of those topics you will never know everything about even if you study it for years is soil.  Soil when you dig into it (pardon the pun) is one of the most fascinating and challenging aspects of building a sustainable, environmentally friendly life.  It effects the most basic parts of living, your food, water and shelter needs are directly tied to and influenced by soil.

Soil determines what food you can grow and how much of it you can grow.  It will be a large factor in determining where groundwater is and how tasty that water is.  It also tells you where you should and should not build a house or other structures.

So to sum up what could be a long rant, you need to know about soil in general and about the soil where you want to build a new life.

Now their are lots of tools out there to help you with figuring out your soil and what it is good for. One of those tool that I want to talk about today is called a soil texture triangle.  A soil texture triangle is basically a chart the enables you to figure out what class of soil you have.  By measuring the amount of sands, silts and clay contained in a soil you will get a soil class which can tell you a lot about what you can do with that soil.

Basic Method

The basic technique to using a texture triangle is to take a small amount of soil and get it a little wet so it is pliable and sticky.  Then just roll and squeeze that bit of soil around in your fingers and palm.  Paying close attention as you play with the soil you will start to notice a few key characteristics.

Clay soils with be sticky and maybe a little slippery but you will mainly notice it sticking to you and itself really well.

Silt soil with have a smooth slippery feel that won't stick like clay does.

Sands of course will be gritty feeling and you can maybe even see individual particles of sand in the soil you are testing.

Once you get a feel for what's in the soil you can consult a texture chart like the one above to help you figure out what you have.  It's fairly easy but it does take experience to really get good at it.  Some common mistakes people make are mistaking silt for clay and overestimating the clay in the soil.  Another common mistake is overestimating the sand.  This happens because sand is so easy to notice in the soil  It's also easy to underestimate the clay as a little clay goes along way.

Doing a texturing test like this can provide a novice soil scientist with some broad ideas about the soil on their land.  For example if you are in a low spot and you find high clay in a texture test that would not be a good place to build a house as water will collect and pool there.

If you want a step by step guide to soil texturing, you can check out this flowchart put out by the US Department of Agriculture.

One you have mastered using a texture triangle you can use the knowledge you gain to better site houses, gardens and that new backyard pool using soil as your guide.  Being able to do this will take you one step farther down the path of true sustainable living.   

Stay tuned for more Science of Sustainability topics.  

              
 

Storing Carrots in the Garden

When you grow a large crop of carrots you can end up with a problem like I have.  You can't possible keep all the carrots you grew in the fridge and you don't have a root cellar where you can store them either.

What does that leave you?

Well luckily most carrots store very well right in the soil of your garden.  They do need some protection in order to survive the coldest temperatures of the winter and if you live in a exceptionally cold climate this still might not work for you.

The key with mulching carrots in the ground is to cover them in a thick layer of mulching materials.  The more you can pile on the better as it will only increase the insulating value of the mulch.  The best varieties of mulch for this are usually some sort of straw as they have the ability to remain light and airy and not get compacted by water and rot.  If you do not have straw then other mulch types like leaves, pine needles and other lawn trimmings should suffice.

Before you mulch make sure you know where your carrots are so you don't have to waste time out in the cold digging around for them.  Then mulch them late in the fall right before you start to get consistent cold temperatures.

One of the unexpected delights about leaving your carrots in the ground is that as they are exposed to cold temperatures the carrot begins to transform its starch into sugar.  What this gives you is a naturally sweet carrot which is a real delight in the middle of winter.

So if by some miracle you have still have carrots in the ground try mulching them over and see what kind of sweet delights the garden can provide all winter.

Science of Sustainability-Soil pH

Soil pH is a critical aspect of soil that must be understood and managed correctly if you want to be able to create and manage a successful sustainable life.  What pH your soil is determines a lot about what you can grow and where you can grow it as soil pH can very from plot to plot.

What is soil pH?  

The easiest way I could think of to define pH is as follows,

p-means power as in 2 to the 10th power = 1024

H- stands for Hydrogen

So pH together stands for the power of Hydrogen ie. how many Hydrogen ions are present in the material you are measuring.

The higher the amount of Hydrogen ions that are present, the lower the pH will be.  This means that when you have a lot of Hydrogen present, the soil will be more acidic. The less hydrogen ions you have the more basic/alkalie the material will be.

The pH scale is what is called a negative logarithmic scale so it increases from 0 which is the most acidic and has the most Hydrogen ions present to the most alkaline or basic at 14.  Each step from 0-1 all the way from 13-14 is higher that the previous number by a factor of ten.

For example the most acidic thing on the pH scale would have a pH of 1 while the most alkali or basic material would have a pH of 100,000,000,000,000 if expressed as full numbers rather than on
the scale.
   

http://bouman.chem.georgetown.edu/S02/lect14/ph.gif 

Soil pH and a Sustainable Life

What I want to really get into now is how knowing about pH is part of building a sustainable lifestyle.  The primary way that pH affects you when you are trying to build a sustainable life is how it affects your ability to grow food.  Certain crops and plants work better with certain levels of pH.  For example strawberries a common garden favorite like a pH between 5.5-6.5.  While other favorites like spinach and asparagus like a soil between 6.5-7.5.  So they they wouldn't make the best garden bed fellows.  The pH of your soil is a critical factor in telling you what can be successfully grown at your location.  Now you may still be able to grow things that are outside their preferred pH range but your success could be questionable.  

Planning your garden spaces out according to pH will save a lot of headache and expense in the long run.  If you have to continually put additives into the soil like lime to counteract acidity then perhaps you need to relocate the garden or grow something else there. 

Measuring soil pH is a really easy and cheap thing to do with today's technology.  You can either do it with a meter like this one or with disposable litmus strips.  A meter like this will give you a more accurate and precise readings than the litmus and they also last quite a long time if taken care of properly.  A meter like this will be useful if you have a large amount of ground to test or if you are consistently making adjustments to your soils pH.  

If you want you can also use litmus papers which when soaked in a solution of soil and water change color to indicate a general level of pH.  They are cheaper than the meter but they are one time use only and you will have to replace them once you run out of papers.


Keep on joining me as I continue to delve into further topics on the Science of Sustainability.  If you ever have and questions about what I post just let me know in the comments and I will get back to you.

Science of Sustainability- What is Soil

To kick off my new series the Science of Sustainability I have decided to start with a topic that is near and dear to me.

The Soil.

Soil is not dirt, I just want to make that clear right from the the start.  Dirt is what happens when soil is no longer doing what it is suppose to do.  Soil can be defined as a mixture of minerals, organic matter, water and air that together form a matrix that supports life.  Without a decent soil, building a truly sustainable life for yourself is impossible.  If you can't grow food, support livestock and otherwise sustainable use the soil you will have nothing that can provide you the basics of what you need.  To truly understand soil you have to understand its components and how they work together to create this life giving substance.

Minerals

Soil is made up of three different sizes of materials.  You have sand, silt and clay with sand being the largest and clay being the smallest.  The different combinations and proportions of these materials are what make up the soil texture.  Soil texture along with soil structure determines how well your soil drains water, soaks up rain, stands up to erosion, and deals with compression forces etc.  The minerals in a soil are derived from the parent material that lies beneath all soils.  That parent material can be limestone, sandstone, granite, volcanic ash, pretty much anything that can be eroded into smaller and smaller particles.  

Organic Matter

The organic matter in a soil is a combination of both living and dead material.  It is everything from the smallest microbe to the largest tree roots that are in the soil.  Organic matter plays a critical part in having a healthy, sustainable soil.  It provides the food and fuel for microorganisms, so that they can enrich the soil and make nutrients available for the next generation of plants.  Organic matter also plays a critical role in maintaining water levels in the soil.  It acts like a giant sponge that soaks in water and releases it slowly as plants need it.

This video from the Soil Science Society of America tells a bit more about soil and whats its microbes can do for us.

Air and Water

Though most people wouldn't consider water and air to be critical parts of soil they are.  If you have adequate pore space which is what holds the air and water then that signifies that you have a healthy, well aggregated soil that allows for good root penetration and water infiltration.  Plus the roots of plant need both air and water to sustain life in the plant.  Like most things in life everything in moderation is best.

Soil and the Sustainable Life

Without healthy well managed soils the future of life and human civilization on this planet is in doubt.  With well managed soils we can continue to thrive and grow as a species.  But it takes more than just good intentions, we have to know what to do in order to better manage our lands.  Stay tuned as I continue my Science of Sustainability series with more information about soil and good soil management.

Also check out this great article on Treehugger that shows how modern farmers and ranchers are getting on the sustainability bandwagon and doing what they can to improve and save their failing soils.            

    

    

The Science of Sustainiblity

To be able to really make a sustainable life work you have to be able to understand the fundamental principles that make it possible.  There are so many things that go into creating a sustainable and environmentally friendly life that it is impossible to keep everything you might need to know in your head.

That is where books, articles, websites and blogs come into play.  With all the resources at our disposal to collect and compile knowledge we can like never before build our own personal libraries.  Now knowledge is no longer the privilege of a chosen few but is available to everyone who can read and comprehend.

So to build a modern, sustainable life you have to become a scientist capable of understanding  the basic underpinnings of what a sustainable life is.

You will need to learn what will provide you with the basics of food, water, and shelter.  But you will  also want to go beyond that and provide the comforts of hot water, electricity and maybe a computer for yourself and your family.

To do that you will need to learn things about raising animals, growing crops, capturing and purifying  water and living a life that you have never given a thought to before.  Its a daunting task that I am doing myself and I try to share my successes and my failures with the world.  I have learned much along the way through trial and error, experiments and careful research but I have much yet to learn.

What I have found useful over the years was my drive to understand the basic fundamentals of how things work.  It pushed me to learn how soil works on a physical, chemical and biological level.  How the delicate balance of nitrogen to carbon can fuel microbes into breaking down compost in a month.  By understanding the basics I could apply the techniques right away without tedious failed experiments.

To make that method available to you I am planing on writing a series of posts on what I will call the Science of Sustainability.  They will cover broad topics of soil, plants, energy, water, and other aspects of sustainability.  They will provide a basic framework of understanding of how things work so that you can easily begin to build a sustainable life.

The posts will be placed simultaneously here and in my Sustainable Living How To Guides section of the blog.