What is used and how they work together defines very important substrate characteristics such as root anchorage, water supply, nutrient retention, water level and air exchange. Basic nutrition, most growers are fairly familiar with and are comfortable talking about. But the physics behind the substrate, is less understood by many. Surprisingly, when explained properly, the physics behind substrates is quite interesting and different from what one might have expected.
BELOW FIND UNIVERSITY STUDIES, LARGE CORPORATE RESEARCH, NOT TO MENTION NOTES FROM THE EDITOR
Optimum Element Levels
Nutrient | Limit in PPM | Avg. PPM |
Major Elements | ||
Nitrogen | 150-1000 | 250 |
Phosphorus | 50-100 | 80 |
Potassium | 100-400 | 300 |
Minor Elements | ||
Calcium | 100-500 | 200 |
Magnesium | 50-100 | 75 |
Sulfur | 200-1000 | 400 |
Trace Elements | ||
Copper | 0.1-0.5 | 0.7 |
Iron | 2-10 | 5 |
Boron | 0.5-5.0 | 1.0 |
Manganese | 0.5-5 | 2.0 |
Molybdenum | .01-.05 | .02 |
Zinc | .5-1.0 | .5 |
.
Conversions for ppm, %, mg/kg
- 1mg/kg = 1ppm
- 1mg/L = 1ppm
- 1ppm = 0.0001%
- 1mg/kg = 0.0001%
- 1% = 10,000ppm
- 1% = 10,000mg/kg
.
ppm to/from milliSiemens/cm
- multiply the milliSiemens/cm reading by 1000 and divide by 2 to get your ppm, or simply multiply by 500
- or
- divide the ppm reading by 1000 and multiply by 2 to get your milliSiemens/cm reading, or simply divide by 500
- Example:
- if your EC reading in milliSiemens/cm is 1:
- 1*500= 500 ppm
- And if your ppm is 500:
- 500/500= 1 EC
.
Equations and Symbols
- 1x10-2 = cm
- 1x10-3 = mm
- 1x10-6 = um
- 1m = 1000mm
- 1mm = 1000um
- 1m = 1,000,000um
Get Up-to-Speed on Microorganisms
Soluable Salt Ranges
Keeping up on your soluble salt range is important. Always have an instrument at hand to check your nutrient levels. The below chart is a general guide as to what levels are acceptable or not.
Electrical Conductivity (EC) of a solution is a measure of ionic compounds dissolved in water. Organic Nutrients are ionic compounds. Another name for ionic compounds is salts. Assuming the water had very little EC before you added the liquid fertilizer, measuring the EC will tell us how much fertilizer we have in our liquid. EC is commonly measured in milli-siemens (mS) and/or Total Dissolved Solids (TDS) expressed in Parts Per Million (PPM). Both will give you the same information of how much fertilizer is in your liquid. The EC and PPM are always in relation. So stating the EC and PPM is redundant. The relationship is 1 EC (measured in mS) = 650 PPM.
Desireable | Permisable | Dangerous | |
EC | .75-2 mS | 2-3 mS | 3 mS & ↑ |
PPM | 500-1300 | 1300-2000 | 2000 & ↑ |
About BioChar Pyrolysis
Quote from:
Daniel D. Warnock & Johannes Lehmann &
Thomas W. Kuyper & Matthias C. Rillig
"Biochar is a term reserved for the plant biomass derived
materials contained within the black carbon
(BC) continuum. This definition includes chars and
charcoal, and excludes fossil fuel products or geogenic
carbon (Lehmann et al. 2006). Materials
forming the BC continuum are produced by partially
combusting (charring) carbonaceous source materials,
e.g. plant tissues (Schmidt and Noack 2000; Preston
and Schmidt 2006; Knicker 2007), and have both
natural as well as anthropogenic sources. Restricting
the oxygen supply during combustion can prevent
complete combustion (e.g., carbon volatilization and
ash production) of the source materials. When plant
tissues are used as raw materials for biochar production,
heat produced during combustion volatilizes a
significant portion of the hydrogen and oxygen, along
with some of the carbon contained within the plant’s
tissues (Antal and Gronli 2003; Preston and Schmidt
2006).... Depending on the temperatures
reached during combustion and the species identity
of the source material, a biochar’s chemical and
physical properties may vary (Keech et al. 2005;
Gundale and DeLuca 2006). For example, coniferous
biochars generated at lower temperatures, e.g. 350°C,
can contain larger amounts of available nutrients,
while having a smaller sorptive capacity for cations
than biochars generated at higher temperatures, e.g.
800°C (Gundale and DeLuca 2006). Furthermore,
plant species with many large diameter cells in their
stem tissues can lead to greater quantities of macropores
in biochar particles. Larger numbers of macropores
can for example enhance the ability of biochar
to adsorb larger molecules such as phenolic compounds
(Keech et al. 2005)."
Check out the entire report at:
Mycorrhizal Responses to Biochar in Soil–Concepts and Mechanisms"
Biochar & Fungi Relationship
Cation Exchange Capacity Information Blurb
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