One of the things we focus most on at Sunshine Permaculture is how to build healthy and resilient soil and how that leads to nutrient density for our customers. We explore different techniques of improving soil structure and microbial life in our soil at both a large scale and a small scale.
Our market garden is where we grow most of the produce we sell to customers around Thailand. We spend a lot of time and energy trying to understand how to improve our soil in a way that is affordable for our customers and builds an ecosystem for the life around us.
The goal is make soil building the central part of our market garden work. It is the primary goal when you are running a market garden. Nicole Masters describes microbes as your underground livestock. You have to treat them the same way as you would treat a herd of cows on your land. You have to keep them fed and happy - that is the only way you will get good results.
The difficult thing is how to do all of this in a way that is affordable and shows results rapidly. The goal for a farmer (or any business) is to reach profitability quickly. In farming the costs can be very high for rapid transformation of land - so the ideal goal is to try and revitalize your land in the lowest cost possible.
Slightly off contour garden beds
At the macro level we designed our garden beds slightly off contour. What that does is that it slows down water when it rains and when we irrigate and soaks that water into the landscape. Having them slightly off contour gives way for water to drain, but not too fast. Having beds perpendicular to contour would move water too fast through the system and not enough water would soak into the ground.
We use beds that are raised off the ground so the roots of the vegetables don't drown in water when it rains and water uses the walkways as a passage to be directed where we want to collect or drain that water.
Pathways between the beds made of woodchips are a good idea in the tropics. They have many different functions:
2. They absorb water in heavy rains and hold that water in place - releasing it slowly
3. Snails don't like walking through woodchips - so you don't have a snail problem
4. In a year or so they decompose and help increase food for fungal life
There's a lot more benefits to adding woodchips in the pathways. We don't directly put them into the garden beds as there are issues related to this. Before putting them in the pathways we age them for about 6 months to let them decompose a bit.
We don't dig or turn over the beds after they have been established. We do a deep tillage before we create the beds - this is because our ground is very hard in the beginning and we need to break up the compaction in order to shape the beds.
Microbial life build structure in the soil by creating glues that attach microaggregates, which as many are glued together form macroaggregates. This is a very simplistic way to look at it, but bacterias create microaggregates and then fungi create glues that form them into macroaggregates. This is what gives soil life structure.
When you pickup healthy soil in a forest, it is often in clumpy parts. Versus when you pickup dirt it is usually very sandy or falls apart in your hand very easily. This is because biological life create these structures so they are able to transport nutrients (amongst many other uses). When tillage happens it breaks all of these glues and kills a lot of the biological life in the soil.
The purpose of no dig is not to rotate or turn the soil. This is to preserve the microbial life that lives in the soil and help build structure for the long term. This is important because the soils becomes more resilient and absorbs more water when it has more structure.
Roots in the soil
Continuing to keep roots in the soil is one of the most vital aspects to improving your soil over time. When there are roots in the ground the plant feed the microbial life that is immediately near the root system. The plants asks the microbial community to gather nutrients for the plants and gives them exudates in return, which you can imagine as sugars. This is a mutualistic relationship that is beneficial for both of the parties.
This gets a bit more complex as diversity and microbial life keep multiplying. They create a healthy ecosystem where births and deaths of microbes leads to nutrients that are released to the plants. This is a very healthy and good place to be as a farmer as you no longer need to supply nutrients to the plants. You have healthy livestock that are keeping your plants healthy.
Building long term soil biology is vital to becoming more resilient to climatic problems. Good biology is like having a good immunity in your body - you are less likely to fall sick and your body is more likely to fight infections on its own (without medical intervention). Spoon feeding nutrients to your plants does not promote a healthy root structure because the plant is getting a lot of nutrients without developing a microbial community around it.
Adding too much compost is also a problem as you might be supplying all of the nutrients for the plants. Your real goal is not to supply nutrients for the plants, but to supply nutrients to grow the biology in the soil. The biology then will mine or gather the nutrients for the plants. We aren't able to realistically supply all of the micronutrients that plants need - they need to rely on the microbial community for that.
The focus for farmers should be how to improve the biology in my soil rather than how to feed my plants. That is a key difference in mindset that leads to regenerating soils rather than sustaining soils. We need to build soil every year we farm rather than keep it the same or mine the soil. There is enough nutrients in all of our soils to feed our plants if we are able to create a healthy soil food web.