The Chemistry of treating manure

In the January 2009 edition of the CSA News, The USDA-ARS in Kentucky and Arkansas are researching how Alum affects Ammonia Producing Micro-organisms in poultry litter.

They found that Alum reduced the bacterial population by 50% and a 3x increase in the fungal population. While the bacteria reductions lower the ammonia volatilization loss, the increase in fungus increases the N mineralization.

The story reports that this study will help researchers develop better litter amendments. View the report at http://jeq.scijournals.org/cgi/content/abstract/37/6/2360

Ok, so what is Alum and what are the other choices in treating litter?

Alum is caustic, makes soil acidic, reduces the ability of crops to grow once spread on your fields, and is expensive.

Another choice for treating poultry litter is PLT. In addition to being astronomically expensive, anyone who willingly applies PLT treated litter to their fields is going to experience massive increases in sodium levels (a much bigger concern than ammonia).

While research is good, there is currently a product on the market that will treat ammonia for pennies, is easy to handle, doesn't cause soil problems, and is safe and natural.

We introduced SuperCal SO4 for treating manure in past blogs, The Smell of Money and Treating Manure with SuperCal SO4, here is what really happens when using different products to treat manure.

Warning - Significant amounts of chemistry below!

Alum

Also known as hydrated aluminum potassium sulfate, and Aluminum Sulfate

Carries an OSHA safety warning of Hazardous

Cost $70 for a 50# bag

How it works
10 NH₃ + 10 KAl(SO₄)2 + 12 H₂0 = 10 NH₄(SO₄)2 + 10 KOH + 10 Al

Ammonia - NH₃ is produced in animal manure by the breakdown of urea and in poultry manure by the breakdown of uric acid. The gaseous emission of NH₃ can be inhibited if converted to ammonium - NH₄. Alum - KAl(SO₄)2, is an acid that produces hydrogen ions - H when it dissolves. The hydrogen ions produced by this reaction will attach to ammonia to form ammonium, which further reacts with sulfate ions to form ammonium sulfate - NH₄(SO₄)2
Ammonium sulfate - NH₄(SO₄)2, is an inorganic chemical compound commonly used as a fertilizer. It contains 21% nitrogen as ammonium ions and 24% sulfur as sulfate ions. In the soil the sulfate ion is released and forms bisulfate, lowering the pH balance of the soil while contributing essential nitrogen for plant growth.

Potassium Hydroxide - KOH, also known as Caustic Potash is also produced. KOH is used in cleaning and disinfection.

Aluminum - Al, the final component of the reaction is a precipitation of aluminum.

Reasons not to apply aluminum to your fields:

It is one of the few abundant elements that have no known function in living cells.
Aluminum is primary among the factors that reduce plant growth on acid soils.
Aluminum disturbs root growth and function.
Aluminum has been implicated as a factor in Alzheimer's disease.
Aluminum can be traced to reduced renal function.
Aluminum has been observed as causing growth retardation in pre-term infants and infants.
May increase the risk of breast cancer; furthermore, aluminum increases estrogen-related expression and breast cancer cell growth.

PLT

Also known as Sodium Bisulfate, and Sani-Flush

Carries an OSHA safety warning of Mild Irritant

Cost $398 for a 50 lb bag

How it works
NaHSO₄ + NH₃ = NH₄SO₄ + Na

Sodium Bisulfate - NaHSO₄ reacts with ammonium - NH₃to make Ammonium Sulfate - NH₄SO₄ and Sodium - Na

Ammonium sulfate - NH₄(SO₄)2, is an inorganic chemical compound commonly used as a fertilizer. It contains 21% nitrogen as ammonium ions and 24% sulfur as sulfate ions. In the soil the sulfate ion is released and forms bisulfate, lowering the pH balance of the soil while contributing essential nitrogen for plant growth.

Sodium - Na, reacts with water to release heat. The reaction with water produces very caustic sodium hydroxide or lye. Sodium and potassium can combine in soil to act as a drying solvent. Sodium in soil at concentrations greater than 1% is detrimental to most row crop growth.

Sodium bisulfate is also used in household cleaners like Sani-Flush, for example.

SuperCal SO4

Derived from virgin mined calcium sulfate dihydrate, also known as gypsum

SuperCal SO4 does not carry OSHA warnings

Cost for a 50# bag $8-$13 in the Midwest

How it works
NH₃ + (CaSO₄- 2H₂O) = Ca(OH)₂ + NH₄(SO₄)2

Ammonium - NH₃from manure reacts with SuperCal SO4 to produce a Calcium Hydroxide - Ca(OH)₂ and Ammonium Sulfate - NH₄(SO₄)2.

Calcium Hydroxide - Ca(OH)₂is used in medicine to treat acid burns, as an antacid, as an anti-fungal and anti-microbial preservative for vegetables in storage. Its also known traditionally as hydrated lime. Calcium Hydroxide reacts with carbon dioxide to form calcium carbonate Naturally offsets the acidity caused by ammonium sulfate

Ammonium Sulfate - NH₄(SO₄)2, is an inorganic chemical compound commonly used as a fertilizer. It contains 21% nitrogen as ammonium ions and 24% sulfur as sulfate ions. In the soil the sulfate ion is released and forms bisulfate, lowering the pH balance of the soil while contributing essential nitrogen for plant growth.

Gypsum - (CaSO₄- 2H₂O), is a pH neutral salt. It contains 22% calcium as calcium ions and 17% sulfur as sulfate ions. Gypsum does not raise or lower pH. Gypsum will naturally leach excess nutrients such as magnesium, sodium, and aluminum. Gypsum will increase the oxygen content of soil, making a better growing medium for crops.