All of the techniques I will explain here compliment each other. Implementing one of them without the others may not lead to good results. They are in order of importance. This post was written with small scale veggie production in mind.
The 6 Essential Practices:
Almost everyone tills, but that does not mean it is a good idea. Let’s examine the evidence and use our own intuition, observation of nature, and logical thinking to come to our own conclusions.
Why do people till? To break up compacted soil, to release nutrients, to remove weeds, to add amendments to the soil.
What actually happens when you till? The soil is broken up, but most of the microorganisms in the soil die from exposure to air, dry conditions and sun. The death of these microorganisms releases all of the nutrients in their bodies, creating a short term flush of plant growth. However doing this year after year will deplete the microorganisms and nutrients in your soil so it will become necessary to add fertilizers, and even still you will be missing the microbes. These microorganisms, which are destroyed by tilling, are the ONLY THING which combats soil compaction in nature. They do this by binding up soil particles into larger aggregates which creates space inside the soil for water, nutrients,and life… it also make the soil loose and easy for plant roots to move through. Even though tilling will temporarily brake up the compacted soil it is actually the primary cause of compacted soil because it kills the microbes in the soil, so you will have to keep tilling more and more to keep your soil loose. The soil will quickly become compacted again after you till unless you have a healthy soil ecosystem to create soil aggregates. Also, tilling will only relieve the compaction as deep as your tiller reaches (only a foot or two at most) whereas a soil with healthy microbes will be loose for many feet down, which allows plant roots (yes even veggies) to reach far down for nutrients and water.
What about weeds? Weeds are actually just a symptom, not the problem itself. They are a symptom of three things: compacted soil, low nutrient soil, bare soil. Tilling creates all three of those things, so it is actually the primary cause of weeds (along with other types of soil disturbance like overgrazing). To get rid of weeds without tilling do the following: mulch so there is NO bare soil, improve your soils with compost, plant densely, have a low growing, perennial, ground cover to shade out young weeds but not your vegetables.
Benefits of No-Till:
- less work
- no need for tilling machines
- lower compaction deep into the soil (if you rehabilitate your soil)
- fewer weeds over the long term
- better soil ecosystem which has innumerable benefits for your veggie plants
- your soil can actually accumulate nutrients instead of constantly losing them
- no bare soil which is good for everything but also prevents erosion
- increased soil organic matter over time because soil decomposition is slowed down ( a good thing)
- better drought resistance because myccorhizal fungi are allowed to grow which bring water and nutrients from far away to the roots of your plants
- no-till will give you better and better results each year, the opposite of tilling
- ability have perennial plants integrated into your veggie garden
Drawbacks of No-Till:
- There will be a transition period after you stop tilling in which you will probably weeds, pests, and poor plant growth. These effects can be almost completely mitigated by applying good quality compost, mulch, and cover crops.(see below)
- Please watch these videos, they will help allay your doubts:
- Elaine Ingham: not a very good communicator, but a brilliant scientist.
- https://www.youtube.com/watch?v=QMvpop6BdBA (only the first 1 hour)
- Gabe Brown: 5000 acres in North Dakota
Technique #2 Mulch
Mulching is the key to No-Till gardening, but it will also help even if you are tilling. Mulching feed the microbes, bugs, and worms in your soil. The mulch will eventually be incorporated into your soil by these organisms, which will increase your organic matter content. Increasing your soil organic matter will allow you to hold more water and nutrients in your soil. Mulching will keep your soil moist during the summer by preventing evaporation (the difference is actually very dramatic), and it will also prevent your soil from becoming waterlogged during the winter. Mulching prevents soil runoff and surface compaction during rain. Mulching keeps the micro climate near the soil cooler in the summer heat and warmer during the night, which helps your plants. Mulching is also the most effective way to control weeds (if your mulch is thick enough).
How to Mulch:
- Cover all soil completely with a layer of mulch that is as thick as you can afford, but probably anything more than 6 inches thick is unnecessary and might shade your young plants too much.
- What to use as mulch?
- Awesome mulch materials: Leaves, wood chips from deciduous trees, manure, and grass clippings (these are best around your brassicas, not other vegetables), rocks (as long as you are not trying to grow root crops because they will eventually be incorporated into the soil over time… rocks provide thermal mass for better plant growth and habitat for snakes which eat slugs)
- Good mulch materials: wood chips (not cedar, though), sawdust, hay, manure
- Not that good, but better than nothing: straw, bark mulch, cedar wood chips, cardboard, paper
Technique #3 Compost
If you watched that Elaine Ingham video you will know the value of compost. Here is the link again: https://www.youtube.com/watch?v=QMvpop6BdBA
Basically compost is a way of quickly and directly introducing beneficial microorganisms into your soil which may have been missing. If you are doing everything right but your soil is still not healthy then you are probably missing some microbes and will need to apply compost. These microorganisms will: extract nutrients from rock therefore increasing nutrients available in your soil, form soil aggregates which reduce compaction and give you better structure, fight off pathogen microorganisms which would otherwise hurt your plants, and lots more. You do not need to apply a lot of compost to get these benefits, but you do need to apply HIGH QUALITY COMPOST in order to get these benefits. Poorly made, anaerobic compost will actually hurt your plants and your soil!
How to make high quality, aerobic compost:
- No matter what, you will need a balanced Nitrogen (greens) to Carbon (browns) ratio. Basically add wood chips or sawdust to every compost pile and you should be okay.
- Option 1: turn your compost whenever there is any sign of anaerobic conditions (smell, white mould) or whenever the temperature gets up to 160 degrees Fahrenheit.
- Option 2: create a very high carbon compost pile and leave it for a year… but this means your compost will need to be mostly wood chips, or sawdust.
Technique #4 Diversity
The more diversity in plant species, root types, leaf shapes, flowering times, etc you have in your garden the more resilient and healthy your garden will be in the face of pests, changing weather, etc.
Technique #5 Perennial Ground Covers
Compost and mulch are great initial solutions for improving your soil, but the best long term solution to get really healthy soil and a really healthy garden ecosystem is to have living plant roots in the ground for as much of the year as possible. Your vegetable crops will not accomplish this because they are mostly annuals. So the obvious solution is to have perennial plants covering your vegetable garden all year round however you have to make sure that these plants will not compete with your vegetables for light and for moisture. So what you need are spreading perrenial plants which will not grow more than a few inches tall and which will develop deep roots to take moisture from parts of your soil that the vegetables cannot access. Here are some example plants which I have selected for the Pacific Northwest Climate: Yerba Buena (native fragrant herb) , Sedums, Creeping Daisy, Alpine Strawberry (give you strawberries as a bonus and is very tough), Yarrow (medicinal) , Chamomile (medicinal), Creeping Thyme (culinary herb)
.Technique #6 No fertilizer
If you can establish a very healthy ecosystem and diversity of microorganisms within your garden soil then you will no longer need fertilizer (yes I am talking about organic fertilizer). This can save you some money and time, obviously. The key thing to understand is that all of the nutrients in the soil have come from the bedrock or from the atmosphere. The bedrock contains all of nutrients plants need in endless quantities, the problem is that the plant cannot access them. However, in nature, this problem is solved by bacteria and fungi which can extract these nutrients from the rock and make them available to plant roots. So if you have a healthy soil with all the microbes needed to extract all of the different minerals from the rock you will never have a nutrient deficiency! Nutrient deficiencies are actually just signs that your are missing some important microbes in your soil. So, as you improve the microbiology in your soil I would recommend reducing the amount of fertilizer you put on your soil (yes, even organic fertilizer) and eventually stopping altogether. Sometimes applying fertilizer can actually disrupt the soil life so that your are inhibiting the microorganisms you need from actually developing a healthy population. Plants are very smart. When they need a nutrient they release “exudates” from their roots which are specifically tailored to grow a specific type of bacteria that will extract the specific nutrient they need from the soil. When you supply a lot of manganese, for example, in a plant available form then the plant will never release the “exudates” to the manganese-extracting bacteria so they will not have a large population and your plants will always be needing supplemental manganese. This whole discussion is not even talking about the potential drawbacks of applying fertilizers based on flawed scientific research (which is what most soil labs use because it allows them to sell more fertilizer) which can create imbalances in nutrient ratios which are bad for your soil and your plants. If you apply fertilizer and see a lot of benefit in your plant growth this means that your soil ecosystem is lacking critical organisms and needs some help.
Some of these suggestions you may not believe will work, some of them are very unconventional. I would recommend that your divide your veggie garden in half… on one half do what you are doing now, on the other half implement everything I recommend. Observe carefully and record the results over at least 3 years. It is always better to find out the truth for yourself instead of just believing what other people (including myself) tell you. I have included links under each section to outside references so that you can see more evidence supporting these techniques.