Arbitrary Recollections of Plant Nutrition and Causal Effect.
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Nutrient reactions
in accordance with Liebig's law of minimum. "When two or more factors limit growth, addition of just one will have little effect. The provision of both will have a much greater influence"
- WIKI
Marginally low in a number of nutrients, one unavailable nutrient limits overall growth, over time.
Increase supply of that limiting nutrient, even slightly, increasing the demand for nutrients and another nutrient, the next unavailable, becomes limiting. Macro Nutrients
C, H, O, N, P, K, S, Ca and Mg
Carbon (Non-mobile)
✒ CO2 and Light
✒ 35-40 mg/L
✒ DIY CO2
✒ Non CO2 methods
✒ Dissolved organic carbon (DOC).
✒ Carbon - Tom Barr
After ten days of CO2 supplementation there should be a noticeable increase in growth.
Environments with elevated CO2 will require non-limiting macro-nutrient and trace due to the vigorous nutrient uptake from the plants. Moderately lit aquatic environments with ample CO2 have 4 ~ 5 times greater growth then low or inconstant CO2 levels. Under higher lighting, CO2 is essential or plants quickly becomes CO2 limited, leading to growth deficiencies and unwanted algae.
Hydrogen
Hydrogen is necessary for building sugars and building the plant. It is obtained almost entirely from water. Hydrogen ions are imperative for a proton gradient to help drive the electron transport chain in photosynthesis and for respiration.
Oxygen
✒ Barr Report Newsletter (BRN) - Oxygen
✒ Dissolved Oxygen 7-8ppm
The efficiency of nitrifying bacteria is at it's best when the water is near oxygen saturation and most oxygen concentrations below 5 ppm are not considered healthy. The approximate saturation level for oxygen at 50° F. is 11.5 mg/l; at 70° F., 9 mg/l; and at 90° F., 7.5 mg/l. Impurities added to the water (i.e. salt) or an increase in altitude (above sea level) further decrease these saturation levels.
Energy from respiration drives metabolic processes. In plants these processes include the absorption of plant nutrients (salts) into roots, transport of potassium (K) into and out of guard cells. Other functions: synthesis of proteins, lipids and structural components of plants such as cellulose and other fibers all require O
2. Synthesis of storage compounds in stems, roots and seeds also require O
2.
Nitrogen (very mobile)
✒ BRN - Nitrogen
✒ Nitrogen cycle.
✒
N-NO3 (Paul Krombholz)
DC Tap, 0.5 - 3 ppm N-NO
3,
Fish waist, (ammonia / nitric acid).
N-NO
3 ≮ 24 ppm
The leaves of a nitrogen deficient plant show an over-all yellow or light green color. The older leaves are more affected than the newer growth because nitrogen is mobile within the plant and will move from the older foliage to newer leaves when in short supply. Older leaves are reabsorbed starting at the tips if the leaf. Plants w/severe nitrogen deficiency can become white/yellow w/tinny leaves.
3 Day exposure to 120ppm of NO3-NO3 (derived solely from KNO3) and 50% mortality rate with C. japonica (Amano algae eating shrimp).
The same has no effect on health of 20 South American species of fish (Barr, 2005).
Calcium (Non-mobile)
Ca++ ≮ 10ppm
DC Tap water 44ppm
✒ BRN - Calcium
Thought to enhance uptake of N-NO3. Calcium deficiency can cause stunting of the terminal buds; developing roots, distorted new growth (twisted, bent, maybe cupped leaves) black spots/white leaf margins and impaired root function.
Magnesium (mobile)
Mg++ ≮ 3
DC Tap water ~9ppm
✒ BRN - Magnesium
Magnesium is the only mineral constituent of the chlorophyll molecule accounting for near 20% of total Mg in plants. Magnesium serves as a structural component necessary for protein synthesis. Most reactions involving phosphate transfer specific to ATP require this element, as well as, the activities of several other enzymes. As an example, insufficient magnesium can restrict RuDP carboxylase and CO2 assimilation. Deficiency symptoms often result in leaf distortion for this reason. Other symptoms include interveinal chlorosis of the lower leaf, in which the veins remain green; advancing to uniform pale yellowing of the leaf, to brown and necrotic. There are no tests of Mg that I know of. To test for Mg, test for PPM General hardness as CaCO3 and test for PPM Ca hardness as CaCO3, i.e., PPM General hardness as CaCO3 minus PPM Ca hardness as CaCO3 = PPM Mg hardness as CaCO3.
✒ GH & KH
My tap water's total hardness (GPG), 5.3 - 11
Alkalinity is 37 - 111ppm
Phosphate (mobile)
DC Tap, ~0.02 ppm, P-PO
4.
Fish waist/Fish food
KH
2PO
4
- A useful animal cell buffering agent, a component of DNA, RNA, ATP, phospholipids, bulbs and flowers.
- GSA, indicates high levels of light, low phosphate and/or low CO2.
- Phosphorus deficiency symptoms are not very distinct and thus difficult to identify. Unlike nitrogen deficiency, young to mature leaves remain dark green at all levels of severity. In most (but not all) cultivars, yellowing is preceded by the appearance of purple anthocyanin pigments, producing a range of autumnal colors in the senescing leaves. Yellowing may spread from discrete interveinal patches, often affecting one half of the blade more than the other - yellowing and necrosis is often asymmetrical. Potassium and magnesium deficiencies also cause chlorosis on older leaves, but in phosphorus deficiency chlorosis usually does not retain a distinct interveinal pattern, as is typical of potassium or magnesium deficiencies. A major visual symptom is that the plants are dwarfed or stunted.
Potassium (very mobile)
K
2SO
4
Deficient in potassium, plants will be deficient in phosphate and/or nitrate uptake reactions.
Plants w/severe potassium deficiency have pin-holes in the leaf that enlarge with a yellow edge surrounding the holes. The leaf is otherwise normal looking.
✒ BRN - Potassium
Sulfate (Moderately mobile)
SO
4
DC Tap water ~54ppm
✒ BRN - Sulfur
Although sulfur is most often regarded as a secondary nutrient,
plant requirements for sulfur are equal to and sometimes exceed those for phosphorus.
However, due to the levels in tap water and added fertilizer, it is rarely limited.
When plants find sufficient nutrients,
