Showing posts with label minerals. Show all posts
Showing posts with label minerals. Show all posts

Thursday, August 15, 2013

Phosphorus

Phosphorus is an essential macro-nutrient for plants and all life on earth. Phosphorus is a component of nucleic acids, ATP and the phospholipid bi-layer that encloses cells.

Phosphorus is a scarce finite resource on planet earth. It is extracted from phosphate rock almost entirely for agriculture use around the world. There are organic and synthetic processes of phosphate extraction in mineral mining.

When is the earth-destructive process of mineral extraction qualified as organic? This has to do with chemicals used in the chelation process of making absorbable phosphate fertilizers from rock. Synthetic chelates like EDTA or DTPA used to strip phosphates from rock appear in trace amounts in non-organic produce grown with synthetic fertilizers. Organic chelates are humic or fulvic acids derived from the natural decomposition of organic material. The phosphates recovered by humic acids are identical to those found in nature.

Optimistic scientists say we have more than 100 years before the end of agriculture (and strike-matches technology). Recycling phosphorus by using manure or animal bones as a source for phosphorus fertilizer on local farms is the approach used by permaculturists. Phosphorus conservation for urbanites and suburbanites can be achieved with hydroponics.

Phosphoric acid is often used in hydroponics to bring the pH of a nutrient solution down.
Plant Nutrition Facts
Phosphorus (P)
Absorbable Forms H2PO4- and HPO42-
Fertilizers Phosphoric acids, super-phosphate, ammonium phosphate, phosphogypsum, apatite, animal waste, bone meal, algae
Symptoms of Deficiency Plant is dark green with purple veins and stunted; burned leaf tips
Action
Necessary in the synthesis of ATP, phospholipids in cell walls and nucleic acids. Promotes growth of roots and shoots.
Plant Nutrition
Phosphorus is necessary during all stages of plant growth. Plants need more phosphorus during periods of advanced expression: blooming and fruiting.
Origin
Synthetic: Extracted from phosphate rock using synthetic chelates that appear in trace amounts in non-organic produce.

Organic: (1)Extracted from phosphate rock using organic chelates like humic acids. Identical to phosphates naturally occuring in soil. (2)Recovered from bone meal, guanos, urine or algae.
Adverse Effects
Mineral sources of phosphorous may contain trace amounts of toxic heavy metals like cadmium, flouride, uranium, radium or polonium. Synthetic phosphates contain trace amounts of synthetic chelates. Phosphate fertilizers leaching into aquatic environments promote algae blooms that kill fish. Flourine, as a component of super-phosphates, contributes to soil sterilization.
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Wednesday, August 7, 2013

Nitrogen

Nitrogen (N) is one of the essential building blocks of nucleotides for DNA and RNA and of amino acids for proteins. Nitrogen is necessary for all of life on earth. For plants, nitrogen is the limiting factor for growth and the primary ingredient in fertilizer. Plant’s can only absorb nitrogen as ammonia (NH3) or as nitrate (NO3). These molecules are relatively scarce compared to atmospheric nitrogen (N2) that makes up 78.09% of earth’s atmosphere. 

Before 1913, all of the nitrogen in plants and animals was produced by organic bacteria with special enzymes that convert atmospheric nitrogen to absorbable forms. Today more than half of the nitrogen in our bodies was produced industrially from fossil fuels using a synthetic process of Nitrogen fixation. Industrial nitrogen fertilizers are a major source of environmental pollution.

The nitrifying reactions of bacteria
Atmospheric nitrogen to ammonia:
N2 + 8H+ + 8e- => 2NH3 + H2
Ammonia to nitrite by Nitrosomonas bacteria:
2NH3 + 3O2 => 2NO2 + 2H+ + 2H2O
Nitrite to nitrate by Nitrobacter bacteria:
2NO2- + O2 => 2NO3-
Ammonia is the first product of nitrogen fixation by bacteria called diazotrophs using the enzyme nitrogenase. These bacteria are abundant in low-oxygen environments like soil, mud and decomposing organic materials. Urea, a component of animal urine is also metabolized by bacteria with the enzyme urease to produce ammonia. Ammonia is a weak base and reacts with acids to form ammonium (NH4+) salts. The ammonium ion in water is readily available for absorption by plants.

Nitrosomonas bacteria convert ammonia to nitrite, which is not a form of nitrogen available to plants. Nitrobacter bacteria convert nitrite to nitrate which is available to plants.
Plant Nutrition Facts
Nitrogen (N)
Absorbable Forms Nitrate (NO3-) and Ammonium (NH4+)
Fertilizers ammonium nitrate, sodium nitrate, potassium nitrate, calcium nitrate, urea
Symptoms of Deficiency Oldest leaves turn yellow and die prematurely; plant is stunted
Action
Necessary for the synthesis of proteins and nucleic acids. Nitrogen is the limiting factor of vegatation and growth.
Plant Nutrition
Plants need nitrogen throughout the grow cycle. Plants use more nitrogen during the vegetative stage to grow and produce leaves. Plants use less nitrogen when flowering and fruiting.
Origin
Synthetic: The major source of industrial nitrogen fertilizer is anhydrous ammonia: a chemical gas most abundantly derived from non-renewable fossil fuels.

Organic: Nitrogen is made available organically through decomposition by nitrogen-fixing bacteria in soil. Organic fertilizers use natural sources for nitrogen like animal waste or composted materials.

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