Soil Fertility

Andrew Laca Agriculture Science Mountain Home High School

Terms and definitions

• Essential Nutrient- Element necessary for plant growth and reproduction, for example: nitrogen, phosphorus, and potassium.

• Deficiency- Plant condition where an essential nutrient is not sufficiently available.

• Symptom- A visual sign or condition that results from a deficiency: symptoms aids in diagnosing a deficiency.

More Terms and Definitions • Fertilizer- Natural, manufactured, or processed material or mixture of materials that contains one or more of the essential nutrients; availible in: – dry form – liquid form – gaseous form

Fertilizer Terms • Analysis- Percentage water soluble content of nitrogen (N), phosphorus (P) expressed as P 2 O 5 , and potassium (K) expressed as K 2 O in the fertilizer.

• Brand- Trademark of the company which produced the fertilizer.

• Complete Fertilizer- Fertilizer which supplies all three primary nutrients, (N,P,K)

Chemical Elements Essential To Plant Growth

• Non-mineral- air and • Mineral- from the soil water – Carbon (C) – Hydrogen (H) – Oxygen (O) – Primary • Nitrogen (N) • Phosphorus (P) • Potassium (K) – Nitrogen (N) – Secondary • Calcium (Ca) • Magnesium (Mg) • Sulfur (S) – Micronutrients • Iron (Fe), Boron (B), Manganese (Mn), Copper (Cu), Zinc (Zn), Molybdenum (Mo), Clorine (Cl)

10 Essential Elements

• Essential Elements – Carbon (C) – Hydrogen (H) – Oxygen (O) – Phosphorus (P) – Potash (K) – Nitrogen (N) – Sulfur (S) – Calcium (Ca) – Iron (Fe) – Magnesium (Mg) C. HOPKINS CAFÉ Mighty Good

Functions of Nutrients for plant growth • Carbon, Hydrogen, and oxygen are needed in the plant processes of photosynthesis of photosynthesis and respiration.

• Approximately 95% of weight of plants comes from products of photosynthesis

Primary Nutrient Functions • Nitrogen (N) – Gives green color to plant – Induces vigorous , rapid growth in plants – Increases protein and yield – Aids and promotes seed and fruit development – Nitrogen constitutes 80% of the atmosphere, yet it is one of the most critical elements for plant growth.

– Plants cannot utilize N as a gas, it must be combined with other elements.

More Primary Nutrient Functions • Phosphorus (P) – Important to germinating seedlings – Contributes to early maturing crops – Necessary for seed and fruit formation – Stimulates root growth

Primary Nutrient Functions Cont.

• Potassium (K) – Necessary for production and translocation of carbohydrates – Produces plumper seeds – Controls Water intake and respiration – Stiffens straw and stalks

Secondary Nutrient Functions • Sulfur (S) – Necessary for nodule formation on legumes – Associated with plant enzyme systems – Stimulates seed production – Affects protein and crop quality

Secondary Nutrient Functions • Calcium (Ca) – Speeds decay of organic matter – Stimulates formation of nitrates – Promotes root and leaf growth – Necessary for nodulation of legumes

Secondary Nutrient Functions • Magnesium (Mg) – Necessary for chlorophyll or green plant color – Increases adsorption of phosphorus – Aids in the formations of fats and oils – Important in plant enzyme system

Symptoms of nutrient deficiencies • Review – Deficiency- Plant condition where an essential nutrient is not sufficiently available.

– Symptom- A visual sign or condition that results from a deficiency: symptoms aids in diagnosing a deficiency.

Primary nutrient deficiency symptoms • Nitrogen (N) – Stunted and Spindly – Yellow, yellowish green or light green in color in foliage (chlorosis) – Older leaves affected first, starting at the tip and moves along the middle of the leaf.

Primary nutrient deficiency symptoms • Phosphorus (P) – Stunted Growth – Very dark green color – Purple leaves or portions of leaves in advanced stages – Older leaves affected first

Phosphorus Deficiency

Primary nutrient deficiency symptoms • Potassium (K) – Shorter plants – Bronzing or browning of leaf color – Lodging (bending of the stem) occurs – Leaves show yellow to brown coloring along leaf margins followed by complete browning.

Potassium Deficiency

Secondary nutrient deficiency symptoms • Sulfur (S) – Young plants have stunted appearance – Leaves have a light-green to yellow coloring – Stems are thin and spindly – Sulfur deficiency symptoms are similar in appearance to nitrogen deficiency symptoms.

Secondary nutrient deficiency symptoms • Magnesium (Mg) – Leaf parts between veins show a whitish color – Leaf tissue becomes yellow, veins remain green (interveinal chlorosis) – Leaves curl upward along the margins

Deficiency Continued • Other conditions besides deficiencies may cause abnormal plant growth. – Cold, wet weather, lack of sunlight, disease, insect damage, and improperly applied chemicals are examples.

Factors that Influence Fertilizer Use • Chemical and physical condition of the soil • Crop to be grown • Climatic Conditions • Time