A Healthy Community Garden Requires Healthy Soil

In a 3 part Blog post one of our community gardeners presents their thoughts on what makes up "Healthy Soil".

I.                 Physical Makeup of Healthy Soil

There is never a bad time to increase the health of your community garden soil. Healthy gardening begins by ensuring that the soil in your garden receives a fresh set of the basics every year at a minimum.  Getting the soil right, in most cases, allows you to avoid many of the common plant diseases and pests that prevent most gardeners from having a productive and nutritious harvest.

Soil is physically composed of weathered rock, organic matter, water and air. But the hidden "magic" in a healthy soil are the small biologic creatures, such as; worms, insects and microbes. Biologic creatures flourish when the soil elements and physical matter are in balance with each other.  Soil is primarily comprised of the following matter:

• Mineral Matter which comprise approximately 50% of the physical area for a healthy garden soil, minerals typically consist of small pieces of earthen rock that has been broken down over time by natural forces such as wind and rain; 
• Organic Matter which comprises approximately 10%  of the physical area for a healthy garden soil, organics typically consist of decomposed remains of soil organisms and plant life including lichens and mosses, grasses and leaves, trees, and all other kinds of vegetative matter; 
• Air which should comprise approximately 25% of the physical area for a healthy garden soil Plant roots, insects, microbes, earthworms and other soil life require this much air to live. The air in soil is also an important source of the atmospheric nitrogen that is utilized by plants; 
• Water which should comprise approximately 15% of the physical area for a healthy garden soil. 

Understanding the texture of the soil in your garden can help you to select the kinds of plants that will thrive in that soil, and also give you an idea of what kind of supplements and soil amendments you need to add or delete to get to the soil you will need to grow a specific kind of plant.  Square foot gardeners and Community Gardeners with mature garden plots probably understand this better than any others.  Raised beds allow the square foot and community gardeners to have different soil texture characteristics and pH values.  Soil textures can be best defined as: 

• Sands; with subcategories of sand, loamy sand and clayey sand;
• Clays; with subcategories of sandy clay, light clay, medium clay and heavy clay;
• Loams; with subcategories of sandy loam, fine sandy loam, loam, silty loam, sandy clay loam and clay loam.

Soil water retention is essential to life. It provides an ongoing supply of water to plants between periods of replenishment. However, remember, plant roots require adequate access to gaps and space in soil to be able to bring in oxygen, nitrogen and carbon dioxide necessary for proper growth and maturation.  Other plants like potatoes and root or tuber plants require soils that are heavier and retain water longer. Herbs and smaller flowering plants prefer a soil that is well drained and lighter with more air cavities.

Next Week Part II:  Nutrients of Healthy Soil