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Organic and Inorganic Fertilizers and Materials for the Home Gardener

Publication Number: P2572
View as PDF: P2572.pdf
Text file for accessibility: File p2572_accessible.docx

Home gardeners today have many choices when considering how to improve the soil and add nutrients. With the renewed interest in gardening practices that emphasize conservation and sustainability of our natural resources, many people have an interest in using organics to build the soil and supply needed nutrients. 

Applying fertilizers and adding soil amendments can impact the pH of the soil. Speed and duration of the reaction depend somewhat on soil type, organic matter, temperature, available moisture, or fertilizer solubility in water. Soil pH is a measure of the acidity or alkalinity of the soil.

Managing soil pH is important for gardeners because plants grow best in certain pH ranges. Plants may also exhibit nutrient deficiency or toxicity symptoms as a result of soil pH. Correct soil pH only when it is substantially higher or lower than required by the plants you are growing.  Select plants that will grow in the natural pH of your soil rather than changing the pH, as long as the existing pH range provides good nutrient availability. Refer to Extension Publication 2571 Soil pH for Landscape Plants for more information on pH and the optimum pH ranges for common landscape plants.

This publication lists selected organic and inorganic fertilizers and amendments, their speed of reaction (nutrient availability), and effect on pH so homeowners and gardeners can develop strategies for better management of plant growth and soil productivity. This information is intended as a reference only and should not take the place of a soil test. 

Improper use of fertilizers can contribute to water quality problems, so always follow recommendations of a soil test to make sure you are applying only what is needed for healthy plant growth.

Table 1. Approximate nutrient value of some organic* materials.

Organic Material

Nitrogen (N) %

Phosphorus (P205) %

Potassium (K20) %

Relative Speed of Reaction

pH Effect

Alfalfa Meal

4

1

1

Slow

Acid

Bone Meal (steamed)

1 to 4

15

0

Slow

Acid

Cocoa shell meal

2.5

1

2.5

Slow

Neutral

Compost

1.5 to 3.5

0.5 to 1.0

1.0 to 2.0

Slow

Neutral

Cottonseed Meal

7

3

2

Slow

Acid

Crushed Granite

0

0

5

Very Slow

Neutral

Dried Blood (Blood Meal)

13

1 to 2

1

Rapid

Acid

Feather Meal

12

0

0

Slow

Acid

Fish Meal

10 to 11

6

0 to 2

Slow

Acid

Hoof and Horn Meal

12 to 14

2

0

Medium

Neutral

Kelp Meal (Seaweed)

1

0 to 0.5

4 to13

Slow

Neutral

Linseed Meal

5

1

1

Slow

Acid

Manure, dairy

0.6to2.1

0.7 to 1.1

2.4 to 3.6

**

**

Manure, duck

0.6

1.4

0.5

**

**

Manure, feedlot

1.0 to 2.5

0.9 to 1.6

2.4 to 3.6

**

**

Manure, horse

1.7 to 3.0

0 .7 to l.2

1.2 to 2.2

**

**

Manure, poultry

2.0 to 4.5

4.5 to 6.0

2.1 to 2.4

**

**

Manure, rabbit

2.4

1.4

0.6

**

**

Manure, sheep

3.0 to 4.0

1.2 to 1.6

3.0 to4.0

**

**

Manure, swine

3.0 to 4.0

0.4 to 0.6

0.5 to 1.0

**

**

Peanut meal

7

1.5

1.2

Slow

Neutral

Pelleted Chicken Manure

2 to 5

1.5 to 3.0

1.5 to 3.0

Slow/Medium

Neutral

Processed Liquid Fish Residue

4

2

2

Medium

Acid

Seabird/Bat Guano

9 to 12

3 to 8

1 to 2

Medium

Acid

Soybean Meal

6

0

0

Slow

Neutral

Wood Ashes

0

2

4 to l 0

Fast

Basic

*Organic fertilizer is defined as a material containing carbon and one or more elements other than hydrogen and oxygen that are essential for plant growth. These organic materials also supply various secondary {sulfur, magnesium, calcium} and/or trace elements {boron, manganese, zinc, copper, iron, and molybdenum).

**The speed of reaction and effect on pH depend on how the manure is stored, the moisture content, and how it is handled before application.

Table 2. Nutrient value* of some inorganic fertilizers.
 

Primary (%)

Secondary (%)

Trace (%)

   

Inorganic

Nitrogen

Phosphorus

Potassium

Sulfur

Magnesium

Calcium

Boron

Zinc

Iron

Speed of Reaction**

pH Effect

Material

(N)

(P205)

(K20)

(S)

(Mg)

(Ca)

(B)

(Zn)

(Fe)

-

-

Ammonium Sulfate

20

0

0

24

0

0

0

0

0

Rapid

Very Acid

Borax

0

0

0

0

0

0

11

0

0

-

-

Calcium Nitrate

15

0

0

0

0

21

0

0

0

Rapid

Basic

Chelated Iron

0

0

0

0

0

0

0

0

12-May

-

-

Di-ammonium Phosphate

18

46

0

0

0

0

0

0

0

Rapid

Acid

Epsom Salts (Magnesium Sulfate)

0

0

0

13

10

0

0

0

0

Rapid

Neutral

Iron Sulfate

0

0

0

7

0

0

0

0

12

-

-

Magnesium Ammonium Phosphate

7

40

6

0

15

0

0

0

0

Slow

Neutral

Mono-ammonium Phosphate

11

48

0

0

0

0

0

0

0

Rapid

Acid

Potassium Chloride

0

0

60

0

0

0

0

0

0

Rapid

Neutral

Potassium Magnesium Sulfate

0

0

22

23

11

0

0

0

0

Very slow

Basic

Potassium Nitrate

13

0

44

0

0

0

0

0

0

Rapid

Neutral

Potassium Sulfate

0

0

50

16

0

0

0

0

0

Rapid

Neutral

Sodium Nitrate

15

0

0

0

0

0

0

0

0

Rapid

Basic

Superphosphate

0

20

0

11

0

21

0

0

0

Medium

Neutral

Triple Superphosphate

0

46

0

0

0

0

0

0

0

Medium

Neutral

Urea

46

0

0

0

0

0

0

0

0

Rapid

SI. Acid

Urea Formaldehyde

38

0

0

0

0

0

0

0

0

Slow

SI. Acid

Zinc Sulfate

0

0

0

16

0

0

0

35

0

-

-

*The nutrient content may vary from what is listed, depending on the manufacturer or purity of the product or other materials blended with the product.

**Soil type, organic matter, moisture, temperature, and water solubility of fertilizer used affect the reaction speed.

Table 3. Rock Dust or Rock Minerals Used as Organic Fertilizers/Amendments

Rock Material

Nitrogen (N) %

Phosphorus (P205) %

Potassium (K20) %

Relative Speed of Reaction*

pH Effect

Granite Meal/Dust

0

0

3 to 5

Very Slow

Neutral

Greensand

0

1

6

Very Slow

Neutral

Ground Limestone

0

0

0

Slow

Basic

Gypsum (Calcium Sulfate)

0

0

0

Medium

Neutral

Hydrated Lime

0

0

0

Rapid

Basic

Rock Phosphate

0

3 to 8

0

Rapid

Acid

Soft Rock Phosphate

0

3 to 8

0

Rapid

Basic

Sulfur, Elemental

0

0

0

Slow

Acid

*Soil type, organic matter, moisture, temperature, and water solubility of fertilizer used affect the reaction speed.

Other MSU Extension Resources

Suppliers of Organic Fertilizers, Rock Minerals, Composts, and Pelletized Poultry Litter in the Deep South by Steve Diver, NCAT Agriculture Specialist National Center for Appropriate Technology - Arkansas office

Test soil to find its pH value.

Gardening vegetables: organic gardening.

Organic crops geared more toward commercial organic crop producers.

 

The authors acknowledge the contributions of Extension Information Sheet 372 Soil pH and Fertilizers revised by Geoff Denny, PhD, Assistant Extension Professor, Plant and Soil Sciences, and Keith Crouse, PhD, former Associate Extension Professor.

 

Publication 2572 (POD-03-19)

Reviewed by Geoff Denny, PhD, Assistant Extension Professor, Plant and Soil Sciences. Originally written by Keith Crouse, PhD, former Associate Extension Professor, Plant and Soil Sciences, and Judy Pennington, PhD, Warren County Master Gardener.

Copyright 2019 by Mississippi State University. All rights reserved. This publication may be copied and distributed without alteration for nonprofit educational purposes provided that credit is given to the Mississippi State University Extension Service.

Produced by Agricultural Communications.

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Extension Service of Mississippi State University, cooperating with U.S. Department of Agriculture. Published in furtherance of Acts of Congress, May 8 and June 30, 1914. GARY B. JACKSON, Director

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Authors

Portrait of Dr. Geoffrey C. Denny
Assistant Extension Professor
Plant Evaluation and Nursery & Greenhouse Production

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