Higher topic: Gardening
Underlying topic(s):

Start a vegetable garden - Lesson 2: Soil
Topic in Gardening courses

Chunks of information

  • A healthy soil is full with micro-organisms that give natural protection to plants. They don't get ill and pesticides are not necessary. It is similar to people eating quality food. Their immune systems are strengthened and weird off most diseases. The Israeli scientists (as mentioned in the article of the link) are focusing on special brands of bacteria that can be injected into a soil. I am familiar with other of such experiments, of mixes of micro-organisms that can be sprayed over a soil and improve the health of the soil. But in general, i prefer to only provide good compost and mulch and other natural materials such as lava flour to a soil. These micro-organisms naturally multiply then without the need to artificially add any substances. More agriculture news and information in my blog A good soil is a living community of organisms, not a dead substrate like it is seen by many farmers today. The secret is to make these organisms thrive. Each plant, each tree, has its own mix of companions of micro-organisms around its roots. The plants and trees on the one side and the micro-organisms on the other side live in a symbiotic relationship, mutually benefiting each other. These processes occur entirely naturally. Micro-organisms of many kinds are present in each good soil and multiply very fast when the right conditions are there. The secret is to give them good conditions, give them a good soil. Nature teaches us how to do this. A layer of a humus-rich topsoil is what does the trick. These micro-organisms and other living organisms in the soil such as rain worms give a lot of fertilizers too. Feed the soil organisms instead of fertilizing the plants.... then the soil will feed the plants.
  • Few things are as important as nurturing a good top soil. Long ago the surface of the earth was mostly barren rock. Through weathering and erosion and the influence of micro-organisms, plants and animals a fertile top soil has formed. This is the black layer of humus that forms the basis for the health of plants, animals and humans. Nature took billions of years to give us this treasure. But most of today's farming methods quickly destroy what is needed for a good future of our children and grandchildren. Farmers need to learn to nurture their soils. You don't need to fertilize the plants, you only need to take care of the soil. Did you know that in a healthy soil fungi grow that provide plants with natural penicillium? There exist over 300 species of penicillium.

Soil classification


Soil geology

Global soils map USDA.jpg


Soil organic matter

Soil organic matter (SOM) is the organic matter component of soil. It can be divided into three general pools:

  1. living biomass of microorganisms
  2. fresh and partially decomposed residues
  3. humus: the well-decomposed organic matter and highly stable organic material.

"What is Organic Matter? Many times we think of organic matter as the plant and animal residues we incorporate into the soil. We see a pile of leaves, manure, or plant parts and think, "Wow! I'm adding a lot of organic matter to the soil." This stuff is actually organic material, not organic matter.

What's the difference between organic material and organic matter? Organic material is anything that was alive and is now in or on the soil. For it to become organic matter, it must be decomposed into humus. Humus is organic material that has been converted by microorganisms to a resistant state of decomposition. Organic material is unstable in the soil, changing form and mass readily as it decomposes. As much as 90 percent of it disappears quickly because of decomposition.

Organic matter is stable in the soil. It has been decomposed until it is resistant to further decomposition. Usually, only about 5 percent of it mineralizes yearly. That rate increases if temperature, oxygen, and moisture conditions become favorable for decomposition, which often occurs with excessive tillage. It is the stable organic matter that is analyzed in the soil test.which often occurs with excessive tillage. It is the stable organic matter that is analyzed in the soil test."[1]

Soil amendments

Short outline of the content of this video:

  • Use sand to improve clay soil
  • Use clay to improve sand soil
  • Make the soil fluffy
  • pH adjustment: you can use wood ash. It increases alkalinity and provides potassium, which is good for root crops.
  • Blood meal: releases nitrogen
  • Bone meal: fairly high in nitrogen, high in phosphorus. It also provides calcium, which is good for tomatoes and cabbage.
  • A few more commercial products

My comments: Using sand to improve clay soil and clay to improve sand soil: It is possible but i personally would not use yellow sand to improve clay soils but rather a good compost that also contains soil with larger particles than those in clay. Personally i don't use additives such as blood meal or bone meal or any other type of commercial organic fertilizers. Instead i make my own compost with good ingredients. But in case your garden is small and you don't have what it needs to make good compost, these types of organic fertilizers can be useful. --JE 11:49, 13 September 2012 (PDT)

Testing soil

Content of this video:

  • It takes nature about 1000 years to form 1 inch of good topsoil. We can do the same in our lifetime with organic gardening.
  • Commercial large-scale agriculture often makes good topsoil go lost.
  • Compost crops like clover, and all legumes add nitrogen to the soil.
  • Compost is great to add to soil.
  • pH: 7 is neutral, neither acid or alkaline.
  • pH test kits & pH meters.
  • Test kits for N, P, K
  • N is for growth of green
  • P is for growth of flowers and fruits
  • K is for growth of roots--JE 12:28, 14 September 2012 (PDT)


See also


  1. What Does Organic Matter Do In Soil? By Eddie Funderburg - The Samuel Roberts Noble Foundation

External links