‘Starting with Fertilizer Basics’

MSU Extension Beginning Farmer Webinar

beginner farmiMisuse

‘Starting with Fertilizer Basics’

George Silva

MSU Extension Educator

Fertilizer Basics

Crop health and misuse

Inorganic

versus

Organic

Soil test

Information

Role of

Fertilizer

Fertilizer

Recommendations

Essential plant

nutrients

Fertilizer

Types

Maximizing

fertilizer

returns

4 R

Stewardship

Outline

Fertilizer/crop/

soil interaction

What are fertilizers

• Materials applied to plants to supply one or more nutrients

essential for growth (natural or synthetic, organic or inorganic,

solid or liquid)

• Usually fertilizers are used to supplement

nutrients provided by the soil

If sufficient nutrients are available in the soil then fertilizers are not

required (testing the soil will save money)

Role

• Fertilizers play a vital role in global food production

• Account for about 40-60% of the total food production

• Expensive item in the cost of production ($150/acre)

Fertilizers do not remedy inherently poor soils

(Eroded, compacted, poor structure or drainage)

Misuse

Misuse of fertilizers can cause contamination of the

environment (groundwater, surface water, greenhouse

gas emissions, etc.)

Concerns for Michigan and the Great Lakes environment Phosphorus contamination of surface water Nitrate contamination groundwater (drinking water)

Photosynthesis - nutrients, water, sunlight

Plants are primary food producers – animals rely on

General crop response to fertilizer

Macronutrients – Nitrogen (N), Phosphorus(P), and Potassium(K)

Required in large amounts and likely to be deficient (BIG 3)

Secondary Nutrients – Calcium (Ca), Magnesium(Mg) and Sulfur(S)

Required in large amounts but less likely to be deficient

Micronutrients – Manganese (Mn), Zinc (Zn), Boron (B), Copper (Cu), Iron (Fe), Molybdenum (Mo), chlorine (Cl), Nickel (Ni) Required in trace amounts

17 Essential Plant Nutrients

Carbon (C), Oxygen (O), and Hydrogen(H) are derived from atmospheric carbon dioxide and soil water

Role of Plant Nutrients Constituent of cell, DNA and cell wall

Cell division

Essential for chlorophyll functioning

Protein (enzyme), sugar, starch and hormone

synthesis

Seed formation

Stress resistance (insect, disease, drought)

The Big 3 Nutrients – Yield Limiting

Every year to most crops - Largest demand and sales

Crop health: Nitrogen deficiency symptoms

Uniformly light green or

yellowing of leaves starting from

the older leaves

Phosphorus deficiency symptoms

Purple coloration early in the season

Potassium deficiency symptoms

Sulfur deficiency symptoms

Manganese (micronutrient) deficiency symptoms

Yellowing between leaf veins

Nutrients are absorbed by the root hairs

Three-way Interaction

Fertilizer

Crop

Soil

• Some fertilizers gets attached to soil particles

• Some are lost to the environment

• Some crops highly responsive to fertilizer

• Some crops prefer certain soils

Most plant nutrients are positively charged

Chemistry 101:

Nutrients are absorbed as ions (+ or -) in solution

Humus and Clay Particles - Nature’s special!!

++

+

++

+

++

++

+

NH4+

NO3-

Most plant nutrients are positively charged

K+

K+ NH4+

Humus and Clay Particles - Nature’s special!!

Clay is rich in nutrients!!

Humus and Clay Particles - Nature’s special!!

Cation Exchange Capacity –Ability to retain nutrients

Negatively charged clay and humus particles

Measured when soil is tested

Types of fertilizers

• Solids, liquids, gases

• Organic versus synthetics

• Fast acting versus slow acting

• Crop responses to liquid and dry fertilizer are similar,

provided the amount and placement of nutrients are

the same.

Fertilizer Bag

By Weight

Fertilizer Grade – Guaranteed nutrient content

Fertilizer Grade –Minimum guarantee on a weight basis – N, P, KBoth granular and liquid fertilizer

A 100 pound bag of 10-10-10 fertilizer:

• 10 pounds nitrogen

• 10 pounds phosphate

• 10 pounds potash

applied on 1000 sq.ft. of lawn

Q. If you purchased a 50 lb bag of 10-10-

10 fertilizer,

how many pounds of N and K are in the

bag?

Answer: 5 lb N, 5 lb P, 5 lb K

If you know the area of your lawn, then you can apply

what is recommended to you

Liquid fertilizers

• UAN (Urea-ammonia nitrate) 28%N

• 10-34-0 (Ammonium polyphosphate)

Analysis Weight (lb) per US Gallon

28-0-0 UAN 10.65

10-34-0 11.60

Example 1. 28-0-0 fertilizer used as starter or sidedress

100 lbs of 28-0-0 contain 28 lbs N

10.65 lbs (1 gal) contain (28/100) * 10.65 = 2.98 lb N

10 gal of 28-0-0 will contain 2.98* 10 = 30 lb N

Common Nitrogen (N), Phosphorus (P) and Potassium (K) Sources

Common Fertilizer Grade NutrientCost

$/ton fertilizer*

Urea 46-0-0 N 564

Anhydrous Ammonia 82-0-0 N 785

UAN 28% N 385

Monoammonium Phosphate (MAP) 11-48-0 N and P 704

Muriate of Potash 0-0-60 K 630

Bulk6-24-24 N, P and K 627

Bulk 16-35-5 + Zn + S N, P, K, Zn, S 726

Inorganic (synthetic) versus Organic Fertilizers

Fast Acting (Soluble) Slow Acting (Microbes have to decompose)

Easy to measure and apply Large quantities

Excess – burn plants Excess – burn plants

Excess – contaminate environment Excess – contaminate environment

Smell – attract rodents and flies

Adds organic matter – WHC of soil

Form of nutrient absorbed by the plant is the sameNitrate (N03

- ) Ammonium (NH4+), Phosphate (PO4

--- ) Potassium (K+ ) ions

Foliar fertilization

• Application of nutrients to foliage

• Only small quantities can be supplied

• Can be used with irrigation water (fertilgation)

• Effective as rescue treatments

• Application of nutrients to foliage

Organic Agriculture

No synthetic pesticides

No synthetic fertilizer

No synthetic hormones or growth regulators

Need to be certified

Does organic produce have more nutritive value than conventional?

Organic fertilizers

Cattle Manure Compost Blood meal Bone meal

Corn gluten meal Greensand Seaweed extract Fish meal

Liming

• Amendment to neutralize soil acidity (pH)

• Generally finely ground limestone

• Applied following a soil test recommendation

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Low pH=Acidic High pH=Alkaline

Neutral

Battery

acidVinegar Orange

juice

Pure

waterBaking

sodaAmmonia Bleach Lye

Acid or pH Scale (0-14)

Measure of acidity (hydrogen ion concentration)

Liming – Excellent investment

Liming – Excellent investment

MSU Extension Pub: E 471 Lime for Michigan Soils

Effect of soil pH on nutrient availability

on a mineral soil

Liming

• Amendment to neutralize soil acidity (pH)

• Generally finely ground limestone

• Applied following a soil test recommendation

The 4 ‘Rights’ of Fertilizer Use. Was the crop fertilized properly?

Soil testing every 3-4 years

Nutrient Management -Determining right rate is critical

Soil testing – basis for fertilizer recommendations

Deficiency symptoms appear too late and not entirely reliable

MSU Soil Test Lab Report

Big ‘three’ –N, P, K

Below optimum

(Buildup )

Optimum

(Maintenance)

Above Optimum

(Drawdown)

Analysis

*

Recommendations

Background

Footnotes

(Buildup) (Maintenance) (Drawdown)

Features:

• Soil pH• Nutrient levels• CEC• Lime recommendation• No test for N• N, P, K, Mg and micronutrient

recommendations for the expected yield

• N and P as starter

*

When P205 exceed 60 ppm the starter P is turned off

Only starter N is needed

*

Mg < 50 ppm in fine

textured soils or

<35 ppm on sandy soils

When Mg is < 3%

exchangeable bases

When exchangeable K

exceeds Mg

*

*

*

*When pH exceeds 7 -testing for Mn and ZnIs suggested

Optimum pH range is 6.5-6.8

The 4R Nutrient Stewardship Concept to

satisfy all stakeholder concerns

Nitrogen placement on potatoes 6-8 weeks

Fertilizer Practice Guidelines P and K are applied at planting or seeding or beginning

of the season (stay in the soil)

N – Split application (subject to loss)

Nitrogen Application

Vegetables and Flowers: Two third of N is applied at

planting. The balance one third is applied 6 weeks

after planting.

Lawns: Split N over 4 applications during the year

(April, May, September, November).

Add water after fertilizer application*

Interpreting Soil Test Results

Add 75 lb/1000 sq ft of lime in the fall or early spring

Add 20 lb 10-10-10 grade/1000 sq ft at planting

(equates to adding 2 lb of N, P, and K)

Add 2 lb urea (46-0-0) grade/1000 sq ft 6 weeks

after planting

(equates to total 3 lb N, 2 lb P, and 2 lb K)

Irrigate

Note:Consider convenience, price and timing

Nutrient Recommendations for Fruit Crops in Michigan

MSUE Pub. E 852 Fertilizing Fruit Crops 1996

Nutrient management in fruit crops

Plant tissue analysis is the most reliable tool for nutrient management in established orchards

Roots reach depths below the soil probe

Optimal nutrient concentrations for leaf and petiole have been established

Soil tests - Pre-plant fertilizer applicationsdetermine soil pH every three years or so

Nutrient management in fruit crops

• Tissue analysis in 2-5 years

• MSU soil testing lab offers the service

Seven “Fail-Safe” Steps for Maximizing

Fertilizer Returns

1. Soil test to determine need

2. Lime adequately

3. Provide other inputs and grow best crop possible

4. Use “right” rate, source, timing and placement

5. Irrigate after adding fertilizer

6. Maximize efficiency /avoid losses

7. Avoid overuse

MSU is an affirmative-

action, equal-opportunity

employer. Michigan State

University Extension

programs and materials are

open to all without regard

to race, color, national

origin, sex, gender, gender

identity, religion, age,

height, weight, disability,

political beliefs, sexual

orientation, marital status,

family status or veteran

status.