If you are just joining me I recommend you read the articles that preceded this article. Here are the links:
Soil Improvement – Your Foundation for Success; Soil Preparation – 1st Key to Soil Improvement; Cont’d. Soil Preparation – 1st Key to Soil Improvement; first part of Adding Organic Matter – 2nd Key to Soil Improvement
Repeated Tilling and Hoeing -Their Effect on Organic Matter
One of the things that I’ll bet will come as a shocker to many is the fact that repeated tilling and hoeing destroy organic matter in the soil. Tilling and hoeing are so common and so much a part of human culture worldwide that it’s almost sad to have to think of them as being something that is not particularly good for our soil. The good news is —-the key word here is ‘repeated‘.
Tilling and hoeing expose soil organic matter to more oxygen and thus oxidation. Oxidation “burns” away the organic matter.
Your plants need oxygen to live and the life forms in your soil need oxygen to live. One of the reasons you prepare your soil deeply when you dig a garden is to aerate the soil. In other words you introduce oxygen into compacted layers of the soil. But, if you continually do this, you destroy the organic matter you are trying to keep. Soil organisms need enough time to do their work without being disturbed.
After your initial soil preparation, assuming that you follow the other practices involved in keeping your soil healthy and alive—- and you continue to add organic material to your soil——-there will be little need to till or to repeatedly hoe. The conditions that call for tiling and hoeing will no longer exist.
Repeated Hoeing and Plowing/Discing – Why its Bad for Your Soil
Repeated hoeing and plowing/discing also destroy the natural structure of the soil that you are striving to maintain for the benefit of your plants. This natural structure with its root channels and cracks and large pores are necessary to conduct water into the soil during rainfall. Some of the cracks and channels are used by the roots of your plants to move through the soil.
“Plough Pan” and “Hoe Pan” – What are they?
When ground is plowed or hoed a “plough pan” or “hoe pan” is created as a result of a smearing action at the bottom of the plough or hoe.
You have to think this one out and imagine yourself hoeing in slow motion. The hoe strikes the ground and you pull if forward. As you do it loosens the top part of soil and smears the soil under the hoe, making it compact.
Plowing with heavy equipment magnifies the above example many times over.
As you know, one of the main reasons for your deep soil preparation is to make the top soil and subsoil loose. When subsoil is compacted (which is the result of plowing and hoeing) it can keep roots and water from infiltrating deeply into the soil.
There will be times you feel you have to compromise in order to keep going forward. We all have to face situations like that sooner or later.
When you are weighing your situation keep the principles of sustainable agriculture in mind and stay as close to them as you possibly can. Just so you’ll know more what I mean I will give you an example of something that happens to me sometimes:
Once I prepare a garden bed, I never till it again.
There are times that I run out of organic material (or mulch) to cover a bed that has just produced a crop. In most cases the mulch that was on the bed with the crop has decayed. If it turns hot the soil bakes and it becomes unsuitable to plant in immediately.
In this case, I usually wait for a soaking rain and then cover the bed heavily with straw I have since acquired. If when I get ready to plant again it is too compacted, I will turn it with a shovel and/or break it up with a hand digger or hoe. That’s a compromise I can live with. And its a compromise from which I think the soil quickly recovers.
The bigger compromise —–and the one I never do willingly-—-and the one from which my soil does not recover quickly —–is having a garden bed without a protective mulch covering. Until I am able to replace enough organic matter —— I need not plant again—-because I will not get the results I want.
Organic Material Makes Organic Matter – So What Organic Materials Do I Use?
Organic material (anything living) decomposes to make organic matter (decayed living matter.)
For your organic garden you will want to use primarily plant material and manure (horse, cow, sheep, chicken) if you have access to any without herbicide residue.
As an organic gardener you will want to stay away from sludge and the dung of dogs, cats, & hogs.
I have never had enough organic material and I don’t really know any organic gardener who has. If you have – consider yourself very fortunate. You’ll have one of the best gardens.
Use as many types of organic materials as you have access to. Maximum soil diversity (more organisms to help your garden) depends on diversity of organic matter.
Organic materials used in the garden can include a wide range of things. Some of the most common are compost, leaves, leaf mold, stems, lawn clippings, plant residue (like straw or the your old daylily foliage or even weeds** that have not produced seeds), kitchen scraps*, wood chips, pine needles, and manures.
* Do not include meat in your kitchen scraps that you put in your garden as it will draw undesirable carnivores to your garden.
** If you mow or pull weeds that have not produced seeds they may be used as organic matter for your garden. If they contain seeds — they will get into your garden soil —–and grow!
Whether to Put into the Soil —-or Leave on Top of the Soil
When organic material (biomass) is incorporated into the soil, there is a short period of high activity by soil life while decomposing the material. Soil organisms use the nitrogen produced and if there are not adequate amounts of nitrogen already in the soil for both plants and organisms, the plants in that soil miss out on the nitrogen —at least until the process is complete.
Obviously this is only a problem if you have crops growing in the soil — but a very easy problem to solve. There are materials you can leave on top ——-for example straw, leaves, pine needles etc. As mulch they will break down more slowly than if they were incorporated into the soil, but that is not usually a problem. Thus, the nitrogen in the soil will still be available for the plants.
99% of the time I put all organic material on top of the soil and allow it to decay. It saves me a lot of time and seems to work wonderfully.
Years ago, when you could readily get manures without herbicide residue, I would get cow manure or horse manure whenever I could. Sometimes I would turn it into the soil. Other times I would spread it on top and cover it with straw.
And then there is compost that you can leave on top or incorporate since it is organic material that has already decayed. (Again, it is the decomposition of the organic material that takes nitrogen.)
The last part of Adding Organic Matter – 2nd Key to Soil Improvement will follow in the next post:
Still to come is:
- Cover Crops
- Reasons to Use Cover Including Why Roots are Important
- A Few Words of Warning
- What I Use
- Where to Find a Good Cover Crop Chart