Plant SciencePlant Nutrition

Topic: Sources of Plant nutrients and Forms. (2032)

Brian Sobecki

Evaluating Organic and Inorganic Fertilizers.

• Organics– Materials related to, produced with or based on

the use of fertilizer or plant or animal origin without chemical fertilizers or pesticides.

– Some of these include• Natural organics

– Straw (cereals, beans)

– Green manures (clover, vetch, peas)

– High Calcium Lime

– Forest Products ( bark and sawdust, humus)

Organics

• Major Animal Materials– Bloodmeal

– Hoof and Horn

– Manure

• Synthetic Organics– Urea

– Sulfur coated Urea

– Urea-formaldehyde

– Biuret

Organics

• Processed organics:– Sewage sludge

– Processed crop residues

Benefits of Organics– Soil tillage improved.

– Water Retention improved.

– Temperature increased. ( beneficial biological action)

– Some of the newer processed organics are granulated for easier application.

– Increased worm population ( increases aeration)

Inorganics

• Inorganics– Materials produced by or composed of matter

other than plant or animal.

• Benefits of inorganics:– Meets consumer desires– Generally lower in cost per unit of plant food.– Generally less material to handle because of

higher analysis.

Inorganics: Benefits cont.

– Consistent and higher Analysis

– Ease of handling

Nitrogen Sources

• Two categories based on availability in the soil:– Quickly available:

• Inorganic salts that are readily soluble in water.

• Produced from raw materials such as Natural Gas and Minerals

• Examples: Ammonium Sulfate, Ammonium Nitrate, and Urea

Nitrogen Sources

– Slowly Available:• Do not go readily into solution in water.

• Will release slowly in time.

• Example: Urea Formaldehyde

Phosphorus Sources

• The most widely used source of phosphorus is rock Phosphate.– Mined, ground and then treated with different

acids to create two different phosphate groups.• Superphosphate: Which is treated with sulfuric acid.

• Triple SuperPhosphate: Which is treated with phosphoric acid.

Phosphorus Sources

• Other sources:• Ammonium phosphate: Organic Phosphorus sources

and slag.

• Slag - byproduct from the making of steel.

Potassium Sources

• Potassium Chloride or Muriate of Potash:– Processed from mined potassium salts.

• Sulfate of Potash:– Potassium chloride treated with sulfuric acid.

• Potassium Nitrate: – Potassium Chloride treated with Nitric Acid

Fertilizers

• Forms of Nutrients:– Liquid– Solid

• Fertilizer Labels– Information included on fertilizer labels:

• Net weight

• Brand and Grade

Fertilizers

• Guaranteed analysis giving the minimum percentage of each nutrient.

– Usually Nitrogen, Phosphorus, and Potassium are given in this way:

» N: P: K

» N = actual % of nitrogen in fertilizer

» P = Percent of (P2O5)

» K = Percent (K2O)

Fertilizers

• To get the actual amounts of Nitrogen, Phosphorus and Potassium in the fertilizer follow these rules:

– To get the actual amount of Nitrogen Multiply the percent of N in the fertilizer by the total amount of fertilizer.

– To get the total amount of Phosphors take the percent of P2O5 multiply by the total amount of fertilizer then multiply that by .44 to get the total amount of Phosphorus.

– To get the total amount of Potassium take the percent of K2O time the total amount of fertilizer then multiply by .83 to get the total amount of potassium.