Green Mopho
Grower of Many Things
So as some of you know, I'm not a fan of the everything-but-the-kitchen-sink living soil water-only mixes. In my experience, they either produce quality OR yield, rarely both. To have the right sized container and expect every mineral to digest and release right on time is unrealistic and very hard to pull off. Add to that, different varieties, growing styles, veg times, container sizes, source water, PPFD, DLI, wet/dry cycles. There is just too much guessing and everything in there will get in the way of everything else. How do you taper off certain nutrients or boost others at different times? And then repeat this exact timing when you recycle the soil. You don't, you hope the microbes do, but microbes move at their own pace. Plus, you can't only use biology to create ions that are just not there enough in the soil and the removal rate may be very high by the plant itself, or even a cover/companion crop. You can't create more boron out of the air with just microbes. Some ions like potassium don't change much availability through biological action.
So what happens with these mixes, very little math or precise measuring, and instead a whole lot of guessing.
However, I should say, I do love the effort and love the people trying to do better by the earth and by the plant! I’m not saying this to hate on anyone or anything. I’m just trying to find a better way.
A lot of proponents of living soil and organics say things like, “feed the soil, and let the soil feed your plant”. But our native agricultural soils are already depleted, which is why we are having this conversation in the first place and opting to mix our own soil. If we had amazing well balanced soil out there in nature, we would just walk out there and fill some pots up with it. The reality is that healthy plants create healthy soil! And we want to create the healthiest plants possible for our consumption and enjoyment.
The concept of “regenerative farming” is regenerating the soil. And that really means plants capturing atmospheric CO2 through photosynthesis and sequestering that carbon into the soil as organic matter. But for us to maximize this cycle, we need really healthy plants, which require certain elements present in certain plant-available forms and ratios. So we need to look at all the tools we have to grow really healthy plants and use them accordingly. Not just things labeled “OMRI” or organic. As cannabis growers, when have we really trusted the government? And we will trust them to tell us what “certified” inputs we should use? On the flipside, most of us have witnessed that the greater amount of biological inputs we use, the better QUALITY our end result is. Which is really what our goal should be…
So what about a lighter soil mix, that still harbor the same, if not more, probiotic activity? Well, let's look at soil biology and how that interacts with soil chemistry for a moment. The soil food web is incredibly complex and we understand very little of what actually goes on. Studies have been done on specific isolated microbes and some basic relationships have been studied between how they interact with each other, plant roots, and minerals.
But what about what we do know?...
Starting with the nitrogen cycle. We know that in nature, there is a nitrogen cycle, from atmospheric nitrogen, to nitrate, to nitrite, to ammonium, and then on to amino acid forming proteins. Then those proteins die and decompose and the cycle starts over. But thanks to nitrogen fixing species, we have an unlimited supply of N2 to draw from. But we can't get to it until we have at least established a healthy and diverse soil community and at least some basic plants that can feed sugars to those microbes and begin to assimilate and cycle this nitrogen. It should also be noted that deep subsoils can also contain trapped nitrates, which is where some nitrate compounds are mined from.
The nitrate cycle has certain cofactor elements that are necessary for the nitrogen to cycle, such as sulfur, magnesium, molybdenum, cobalt, and nickel. So for this to all work, these elements have to be present and available.
Next is phosphorus. Phosphorus is one of the most abundantly reactive elements on earth. It forms the strong structure of many animals, including the bones of humans. Phosphorus can form complex chains that become insoluble and very slow to break down. Although phosphorus is abundant on the Earth's crust, free phosphorus for most plants to use is incredibly scarce and most smaller plants have evolved to have it in scarcity. Perennials like most trees are more well adapted to take up large amounts of phosphorus through huge root systems and years and years of biological interaction with the soil, mostly fungi. There is evidence of a phosphorus cycle in nature as well.
Potassium is much more free flowing and abundant. It is a "soft" mineral and one of the first minerals to be released in decomposition. The only conditions that make it tie up for plants are alkalinity. There aren't many aerobic soil microbes that help release or cycle it, it mostly stays ionic. It also antagonizes slower moving "hard" minerals like calcium. So we can throttle and steer potassium, especially since plants need it in different amounts throughout the life cycle, and use it for different types of growth at different times. We can source that potassium organically and don't need much biology to release it, and have the ability to time it.
The saying goes, "Calcium is king". The problem with hydroponic growing is you can never truly make everything available and have in reserve at the same time in the right ratio. This is why in hydro you have to tweak the formula 2 or 5 times throughout the life cycle. The cations in particular, are always getting in the way of each other, and with very little soluble calcium sources, you can't feed that much calcium without it becoming a problem or overdoing it on nitrate or chloride. But calcium plays one of the most important roles in soil, it provides structure in the electrostatic framework of the soil complex. With enough calcium, you don't need perlite. Without calcium, even with perlite, you will end up with tight compacted soil. So we know we need to keep calcium high in our soil, even if some of that calcium isn't available.
Boron and silicon are all connected to calcium to build strong cell walls, and support calcium in building a strong healthy plant frame and structure. Boron is also pretty free flowing and doesn’t create insoluble forms easily, but because it is required in small amounts, it is often fleeting and easily removed or leached from soil. Silicon is highly reactive and although abundant, very little is plant available. There is also a silicon cycle in nature and geology, and it can displace carbon, i.e. petrified wood. Most plants have the ability to pull some silicon from soils through root exudate action.
Iron, manganese, zinc, and copper are all necessary for various plant functions, but are generally reactive and oxidizing metals. They tend to exist in nature as oxides. They need to stay available in soil for plants to a certain degree, although a soil can hold a reserve of it and can release some through biological activity. However, the lack of these elements in soil will greatly reduce the diversity of soil biology. But too much will inhibit a diverse biology. It needs to stay in balance.
Stay tuned for some concepts and starter soil recipes....
So what happens with these mixes, very little math or precise measuring, and instead a whole lot of guessing.
However, I should say, I do love the effort and love the people trying to do better by the earth and by the plant! I’m not saying this to hate on anyone or anything. I’m just trying to find a better way.
A lot of proponents of living soil and organics say things like, “feed the soil, and let the soil feed your plant”. But our native agricultural soils are already depleted, which is why we are having this conversation in the first place and opting to mix our own soil. If we had amazing well balanced soil out there in nature, we would just walk out there and fill some pots up with it. The reality is that healthy plants create healthy soil! And we want to create the healthiest plants possible for our consumption and enjoyment.
The concept of “regenerative farming” is regenerating the soil. And that really means plants capturing atmospheric CO2 through photosynthesis and sequestering that carbon into the soil as organic matter. But for us to maximize this cycle, we need really healthy plants, which require certain elements present in certain plant-available forms and ratios. So we need to look at all the tools we have to grow really healthy plants and use them accordingly. Not just things labeled “OMRI” or organic. As cannabis growers, when have we really trusted the government? And we will trust them to tell us what “certified” inputs we should use? On the flipside, most of us have witnessed that the greater amount of biological inputs we use, the better QUALITY our end result is. Which is really what our goal should be…
So what about a lighter soil mix, that still harbor the same, if not more, probiotic activity? Well, let's look at soil biology and how that interacts with soil chemistry for a moment. The soil food web is incredibly complex and we understand very little of what actually goes on. Studies have been done on specific isolated microbes and some basic relationships have been studied between how they interact with each other, plant roots, and minerals.
But what about what we do know?...
Starting with the nitrogen cycle. We know that in nature, there is a nitrogen cycle, from atmospheric nitrogen, to nitrate, to nitrite, to ammonium, and then on to amino acid forming proteins. Then those proteins die and decompose and the cycle starts over. But thanks to nitrogen fixing species, we have an unlimited supply of N2 to draw from. But we can't get to it until we have at least established a healthy and diverse soil community and at least some basic plants that can feed sugars to those microbes and begin to assimilate and cycle this nitrogen. It should also be noted that deep subsoils can also contain trapped nitrates, which is where some nitrate compounds are mined from.
The nitrate cycle has certain cofactor elements that are necessary for the nitrogen to cycle, such as sulfur, magnesium, molybdenum, cobalt, and nickel. So for this to all work, these elements have to be present and available.
Next is phosphorus. Phosphorus is one of the most abundantly reactive elements on earth. It forms the strong structure of many animals, including the bones of humans. Phosphorus can form complex chains that become insoluble and very slow to break down. Although phosphorus is abundant on the Earth's crust, free phosphorus for most plants to use is incredibly scarce and most smaller plants have evolved to have it in scarcity. Perennials like most trees are more well adapted to take up large amounts of phosphorus through huge root systems and years and years of biological interaction with the soil, mostly fungi. There is evidence of a phosphorus cycle in nature as well.
Potassium is much more free flowing and abundant. It is a "soft" mineral and one of the first minerals to be released in decomposition. The only conditions that make it tie up for plants are alkalinity. There aren't many aerobic soil microbes that help release or cycle it, it mostly stays ionic. It also antagonizes slower moving "hard" minerals like calcium. So we can throttle and steer potassium, especially since plants need it in different amounts throughout the life cycle, and use it for different types of growth at different times. We can source that potassium organically and don't need much biology to release it, and have the ability to time it.
The saying goes, "Calcium is king". The problem with hydroponic growing is you can never truly make everything available and have in reserve at the same time in the right ratio. This is why in hydro you have to tweak the formula 2 or 5 times throughout the life cycle. The cations in particular, are always getting in the way of each other, and with very little soluble calcium sources, you can't feed that much calcium without it becoming a problem or overdoing it on nitrate or chloride. But calcium plays one of the most important roles in soil, it provides structure in the electrostatic framework of the soil complex. With enough calcium, you don't need perlite. Without calcium, even with perlite, you will end up with tight compacted soil. So we know we need to keep calcium high in our soil, even if some of that calcium isn't available.
Boron and silicon are all connected to calcium to build strong cell walls, and support calcium in building a strong healthy plant frame and structure. Boron is also pretty free flowing and doesn’t create insoluble forms easily, but because it is required in small amounts, it is often fleeting and easily removed or leached from soil. Silicon is highly reactive and although abundant, very little is plant available. There is also a silicon cycle in nature and geology, and it can displace carbon, i.e. petrified wood. Most plants have the ability to pull some silicon from soils through root exudate action.
Iron, manganese, zinc, and copper are all necessary for various plant functions, but are generally reactive and oxidizing metals. They tend to exist in nature as oxides. They need to stay available in soil for plants to a certain degree, although a soil can hold a reserve of it and can release some through biological activity. However, the lack of these elements in soil will greatly reduce the diversity of soil biology. But too much will inhibit a diverse biology. It needs to stay in balance.
Stay tuned for some concepts and starter soil recipes....
