Organic Gardening
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Soil Building
By Sue McDonald
So, you're ready to garden!
Maybe you've entertained the idea of growing some of your own food.  Perhaps you are a gourmet cook.  Your idea of organic, wholesome herbs and vegetables includes knowing how those foods were grown.  Whatever your reasons for growing, you need to begin this challenge by assessing the needs of your soil.

Know Your Soil
In order to have healthy plants, you've got to have healthy soil and the first step in making your soil healthy is to test it and find out what it needs.  Many nurseries will test a sample of your soil for a nominal fee or even for free.  They may provide a kit for soil testing as well.  Seed catalogs also sell them.  Often the County Extension Agent's Office provides a soil testing service or can direct you to a lab that will.  It can not be stressed enough: KNOW YOUR SOIL!  ADD THE AMENDMENTS!  The single most important step to healthy plants, less disease and fewer cases of damage by pests is to get your soil in top shape. It's not hard.  Even a gardener on a tiny plot can do wonders with good organic soil practices.

What is Soil?

Soil is the loose top layer of the Earth's surface.  It consists of a variety of horizontal layers called horizons.  Organic matter, minerals and other solid matter forms the basis for soil.  Sand, silt and clay in varying proportions determine the texture of the soil while air and water fill the gaps between the solids.  Sand particles are the largest measuring between 1/50th and 1/500th of an inch.  Pick up a pinch of soil between your fingers and rub them; the sand feels gritty.  Silt particles are smaller: between 1/500th and 1/2,500th of an inch.  Silt feels like a powder.  Clay particles are smaller still.  At 1/12,000 of an inch and smaller they are too small to be seen even with an ordinary microscope!  Clay feels slippery when wet, rubbery when moist and hard when dry.
Clay:  is sticky when wet.  Too much clay causes water to drain slowly which can lead to problems with run-off and erosion.  When dry, it hardens and cracks on the surface causing excess evaporation and upsetting root systems.  It compacts easily.
Sand:  Drains quickly.  Too much sand prevents plants from absorbing nutrients, as they leech away.
Loam:  The mixture of clay, sand and silt that provides moderate drainage and good aeration.  Loam is well-drained and promotes fast, deep root formation and nutrient retention.

pH Factor
We've talked about soil types.  Now, let's discuss the pH factor.  pH is a measure of acid to alkalinity.  Just as a human blood stream has a pH, soil also has a pH.  It is measured on a scale of 0 (most acid) to 14 (most alkaline); a pH of 7 is considered neutral.  When the soil pH is to high or too low, the availability of nutrients to the plants is reduced, leading to poor growth and weakened plants.  Disease soon follows.  Most plants can grow in a pH of 4-8, though you will want a soil pH of 6.5-7 for most vegetables, fruits, nuts and flowers.  If your soil is above a pH of 7.5, your plants won't be able to absorb the available iron.  Iron chlorosis appears as a yellowing of the leaves with their veins outlined in green.  The quickest remedy is an iron spray directed at the leaves.  However, a longer lasting fix is to reduce the alkalinity with compost, copperas, iron sulfate, sulfur or cotton seed meal.  Read the labels for amounts per square foot.
A soil that is too acidic for your plants is just as bad.  You can correct it with lime.  Again, read the labels.  If you find that providing a soil condition for special plants is too difficult, check the natives, (plants, that is), for some that thrive in your native soils with a small amount of amending.  Upkeep on a plant that requires excessive pH maintenance can be frustrating and maybe not worth the extra effort.

Does the word compost mystify you?  Turn you off?  Make you think of smelly piles of rubbish?  It doesn't have to.  You can compost!  You need to.  Your plants will thank you, your garden will flourish and your floral bouquets will delight all who see and experience them.  And, you will be providing a valuable service to your self and your planet for future generations!  While you await the results of your soil test (3-6 weeks), you can be doing something great for your land.  To begin with, let's familiarize ourselves with what composting is all about.

In its essence, composting takes wastes and heats them up; decomposing them to such an extent that their chemical make-up (when placed in your soil) becomes readily available to your plants.  This nurtures them with vital elements necessary for their good health and ultimately, yours.  Nothing tricky in that.

To compost you need to find a place to put the materials.  It should, of course, be near the garden.  If you are planting in containers or do not need a large amount of compost during the year, you may want to purchase a small-scale ready-made compost bin.  Many home and garden supply stores carry them, as do the major garden and seed catalogs.  Instructions for use are usually included.  Place your compost pile near a water source as you will want to sprinkle it on occasion, especially during dry weather.  You may also want to cover it with plastic sheeting.

To the basics then:
Use kitchen garbage.  No meats or meat products.  Shred or blend into slush.  Use old coffee grounds (unbleached filters are best).  Below is a list of other possible ingredients, larger items such as twigs and leaves should be chopped with a mower or shredder:

Grass Clippings 
Small twigs 
Egg shells 
Wood chips 
Nut shells 
Garden debris 
Green hay 
Tomato or Squash vines 
Flower Stems 
Corn stalks 
Animal Manure
The most popular method of composting for the home gardener is called the Indore Method.  It was devised by Sir Albert Howard at the beginning of this century.  In this method the compost heap is exposed to the air and kept moist (not soggy) for the maximum microbial action.  This method turns most of the carbon content into energy creating heat and carbon dioxide which passes into the air.  The interior temperature in an active heap can rise as high as 160° F (71°C).  Some composters cover their heaps with plastic to keep the moisture content constant.  This is a good practice in dry areas and during times of heavy rainfall.

Building Your Pile
To build your compost pile (or bin if you don't like the unkempt appearance of an open pile) you can use the following guidelines:

For the Indore Method, the average pile is 6 feet deep by 3-5 feet high and  10-30 feet wide.  Begin by spreading a layer of plant wastes over the area to be covered by the pile.  Then, add a 2" layer of manure (any, except human).  Follow this with a thin layer of topsoil about 1/8 of an inch thick.  Next, sprinkle lime, phosphate rock, granite dust or wood ash to increase the mineral content of the finished humus.  Do not add lime if an acid compost is needed.  Water the pile and keep layering until the desired height is reached. Don't walk on it or compact it in any way!  This will slow down the aeration process.  Tubes of drilled p.v.c or wire mesh may be inserted 3-4 feet apart to increase air flow if desired.  Within a few days, the pile will heat up and shrink in size.  2-3 weeks after it's started you should use a shovel or pitchfork to turn the pile and then again after 5 weeks.  That's all there is to it! In about 3 months you should have an abundant supply of organic humus to feed your soil and ultimately, yourself!

Once you've gotten your soil test back and purchased you amendments, use a seed spreader or hand broadcast them over your beds (flower, vegetable, etc.)  Then, spread your compost and turn it all under.  If you have the time, let it all sit for a season so the nutrient have a chance to settle down into the "root zone" of your future garden.  If you have used organic amendments, they will break down slowly.  This will allow you to plant sooner without fear of "burning" your plants.  Later in the season, you can side-dress with additional compost or manure tea to bolster you plantings.

If you have a large field, you can plant legumes such as alfalfa, clover or vetch.  Properly inoculated, these legumes can produce staggering results.  Alfalfa and clovers are the most efficient nitrogen fixers.  With the right management, they can fix 100 pounds or more of nitrogen per acre.  Planting legumes and turning them under at flowering, is the simplest and most economical way to get nitrogen into your soil for plant availability.  Another excellent source of nitrogen (if it is available in your area) is seaweed!

Check with your County Agent or a Master Gardener for a suitable cover crop for your area and season.  Knowledgeable nursery people, herb societies, local garden clubs and that next door neighbor with the beautiful garden can be of tremendous help in your efforts to grow a healthy garden.  Don't hesitate to ask either, most gardeners love to talk about their gardens!

Plant On!

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Sue McDonald is an avid gardener living in Boise, Idaho.
She is a regular contributor and editor to the Better Earth News.

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