Seed saving, permaculture and regenerative education New Zealand
Improving the Soil with Clay/BioChar
January 2017 - by Kay Baxter
In all my years of gardening I have never had such a satisfying or easy job. This is the first season I have been able to plant seedlings into the garden, or seed in some cases, and just watch them grow.. apart from watering, and weeding occasionally.
I have seen no water stress, and it has been quite hot and dry all season, and none of the seedlings or plants have stopped growing at any point which has previously been normal for me both heavy clay and sandy soils at times.. some kind of stress, and growth stops, often nutrient lack but could be lack of water or air in the soil etc etc
I have usually found, over my entire gardening life, that once my plants go in the ground I’m then watching for when I need to feed them again to keep them growing fast… in the past I used things like liquid fish to give them a boost or liquid comfrey.. in more recent times , I’ve used EF:Nature’s Garden, or EF:CalPhos etc and this season I made my own liquid fertiliser I called Kay’s Liquid Gold.
It worked, it was good but I don’t need it anymore!!!…. All of my plants are growing from day one and not stopping until they are ready to pick. Everything is growing faster and ready to eat earlier than I have ever had before, and I don’t need to apply any kind of foliar or solid fertiliser to keep them growing… and their brix levels are high. See chart below.
It is essentially about getting the basics right … air.. 50% air in our soil, moisture, always moist… then carbon.. humus and biochar ….then minerals and microbes.
In my sandy soil I had the air once I double dug it, I had water to put on, I made a lot of compost….and I put on lots of fertiliser, albeit the really good stuff….. and it continued to be hard work…. We then added clay. Clay has a far higher cation exchange capacity than sand and that helped a lot. The higher the cation exchange capacity of the soil the higher the ability of the soil to hold moisture nutrients and microbes….then we added 5kgs of CHARGED biochar per sq m and that changed everything. Getting the carbon levels high enough to be holding the minerals and water and microbes was the key. We would have saved a lot of time and a lot of money if we had done that on day one!!!
If you too have less than ideal soil to be growing the nutrient dense food that is to nourish your family then I know now, how you can vastly improve it, in far less time than it took me.
It is all about air, moisture, Cation Exchange Capacity, carbon, minerals and microbes.. in that order!!!!!
In my super compacted sandy soil (old sheep paddock where sheep were set stocked for 100 years), if I were beginning a home garden again, and I was buying product to set myself up I would
Cover area to become garden in plastic to kill the grass and their roots
Lay out beds with pegs and string and double dig to incorporate air into the soil (clay soil the same thing)
Buy charged Biochar (charged with balanced minerals and activated with compost tea..not just activated.. that is critical), and apply at 5kgs (ideal amount.. less is still very good) per sq m over the surface of the bed. At 30 cents a kg it is not exorbitantly expensive for a home garden at that rate.
Apply clay …after having tested by Grant at EF to ensure it is the right kind of clay….at a rate of 2-3 cm over the entire garden
Apply biointensive compost made according to my Art of Composting Booklet at an ideal maximum rate of 2-3 cm over entire bed surface… if my mineral levels are still very low because of poor soil to begin with this is the place I would now be adding Nature’s Garden as explained in Booklet
. fork.. the biochar, clay and compost into the top 30cm of garden bed.
Continue to apply highly mineralised compost each time you plant seedlings or Nature’s Garden. Balanced minerals or recycle your own humanure and urine.
The clay and the biochar and compost together will have raised the Cation Exchange Capacity of the sandy soil so much that this soil will now be able to
hold the moisture for far longer periods, hold far more moisture.. far less issues with water stress, less often watering necessary.
This soil will now have the capacity to hold onto the minerals and fertiliser applied so that if they are not all needed at time of application they will be electrically held until they are needed… because of the higher Cation Exchange Capacity created by the clay and the Biochar….. sand has a CEC of around 5, clay around 40, and Biochar of ????. The CEC is a reflection of the ability of something to attract and electrically hold onto either water or minerals
This soil will now have the capacity to maintain the air spaces ( biochar is structural carbon that will not collapse)
This soil now is now a perfect habitat for microbes and fungi with air, moisture and a place to live (cupboards in the biochar)
This Soil will now have a high capacity for building humus and life (regeneration) because of the combination of biochar, clay and compost and the right moisture and air conditions
Above all else this soil is now able to easily grow high brix plants because the photosynthesis process is not held up by a lack of air, moisture or minerals, or microbes and so as our plants photosynthesis more and more efficiently they are able to sequester minerals and energy from the universe above them and the microbes and fungi in the soil below them and make high levels of sugars which in turn are stored in the soil and used in part to ‘grow soil’.. ie by getting things working to begin with the natural processes of life building itself.. following the laws of nature….are able to continue building soil and ecological health.
By following the basic laws of nature in all of this and putting in the energy to get things ‘going’ again, it is possible to create something that has the ability to take on a life of its own and continue to do the work for us, with some far less expensive and more locally, very locally produced nutrient sources to maintain the system. Ie our own recycled humanure and urine, plus compost made from the carbon crops grown in the garden. We are well down the track at this point of having created our very own Terra Preta dark earth.. by far the most valuable thing we could be investing in on this planet today, in my opinion!!!!!!.
PS... IF you don’t like the idea of the double digging, or that is what is holding you up then I suggest you read Shaked’s article following. He is achieving the same result using a different aeration method, which will work for some of us very well.