Sustainable Small Farming and Ranching

Soil Testing and AnalysisNutrient Management Basics

Slides adapted from the Living on the Land curriculum, University of Nevada-Reno, Sue Donaldson, et al. 2001

How do I know what to add to my soil???

Test your soil!

UNCE, Rno, NV

What Information Does a Soil Test Provide?

Soil textural analysis

pH and salts Soil nutrient

content Fertilization

recommendations

A Fertile Soil Has:

The right kinds and amount of nutrients to grow pasture or crops

Low salinity and sodium

Close to a neutral pH (about 7)

Plenty of organic matter USDA NRCS Photo Gallery

Prior to seeding a crop in new ground At least every three years for established perennial crops Frequently enough to make good decisions on fertilization When it is cost effective

How Often Should I Take a Soil Sample?

How to take a sample

First select the site. Your soil sample should represent only one soil type or soil condition.

OSU Extension Service

Each sample should consist of sub-samples taken from about 15 locations within the same soil type or sampling area.

OSU Extension Service

How to take a sample

Use the “slice” method for a representative sample.

UNCE, Reno, NV

How to take a sample

Soil test results

What do my soil test results mean?

What nutrients do plants need?

How can I supply those nutrients?

What kind of information does my soil test report provide?

Particle size analysis (texture)

Soil organic matter content

pH Soluble salts Nutrient content

USDA NRCS

Particle size analysis

Provides the relative percentages of sand, silt, and clay

Allows determination of soil textural class

A loamy texture is generally best for most plants

NRCS, Bozeman, MT

Soil organic matter (OM)

Living or dead plant and animal residue

Measured in percent

OM content is highly variable

Generally, 3% to 8% OM content is good for plants

UNCE, Reno, NV

pH

Indicates relative acidity or alkalinity

pH 7 = neutral; less than 7 = acid; more than 7 = alkaline or basic

Adapted from library.thinkquest.org

Soil pH and nutrients

Adapted from www.soil.ncsu.edu

Widest part of the bar indicates maximum availability

What makes soils acid?

Acid soils: pH is below 7 Soils become acid because of heavy

rainfall that weathers soils quickly Basic cations such as calcium,

magnesium, and potassium are leached from the soil profile

This natural weathering process makes soils acid

Raising the pH of acid soils

Add lime to raise the pH (making soil less acid)

Lime most often consists of calcium carbonate

Plant response will be relatively slow, taking weeks or months

What makes soils alkaline? Alkaline soils: pH is above 7 Soils that have not been greatly

weathered or leached Some alkaline soils are high in calcium Reduces solubility of all micronutrients

Adapted from library.thinkquest.org

ag.arizona.edu

Example of crop in alkaline soil

Soluble salts

A measure of inorganic chemicals that are more soluble than gypsum, such as sodium, calcium, magnesium, chloride, sulfate and bicarbonate.

Salty soils are a problem in arid regions or in poorly drained soils

USDA NRCS

Managing salt-affected soils

Select plants that can tolerate salinity

Avoid excess or salty forms of fertilizers

Incorporate organic matter If appropriate, add sulfur to lower

the pH

Nutrient Management

Meet crop nutrient needs

Maintain soil quality

Conserve resources Protect water quality -- reduce leaching and runoff risk Click on image to start video

Plant Nutrients

Major Nutrients Nitrogen Phosphorus Potassium Calcium Magnesium Sulfur

Micronutrients Boron Iron Manganese Zinc Copper Chloride Molybdenum

Macronutrients

N = nitrogen P = phosphorus K = potassium

More macronutrients

Ca = calcium Mg = magnesium S = sulfur

Micronutrients

Fe = iron Mn = manganeseZn = zincB = boronMb =

molybdenum

Ni = nickelCu = copper Co = cobaltCl = chlorine

Questions to ask yourself before you add fertilizer:

1. Which elements do I need? (N, P, K, S, Ca)

2. How much do I apply? 3. What type of material do I

use?4. Which application method is

best?5. When is the best time to

apply it?

Types of fertilizers

Chemical fertilizersOrganic fertilizers (bone meal,

compost, manure,etc.)

www.farmphoto.com

Organic Materials

Little or no processing

Low nutrient content Slow release of nutrients

Plant, animal, or mineral sources

Nutrient uptake

The forms of nutrients taken up by plants are the same for all types of fertilizer -- manufactured or organic.

Organic materials:Fertilizers vs. Soil amendments

Fertilizer 1. High nutrient content and availability. 2. Main benefit is nutrients. 3. Relatively small amounts applied.

Soil amendment 1. Low nutrient content and availability. 2. Main benefit is organic matter. 3. Large amounts applied.

How much fertilizer do I need to apply?

Estimate the amount of fertilizer needed based on soil test results, crop needs and area to receive fertilizer

Most fertilizer recommendations are in pounds per 1000 square feet, or pounds per acre

Fertilizing with manures

Good source of nutrients and organic matter

Protects soil from raindrop impact and erosion

Local supply often available at no cost OSU Extension Service

Poultry manure is high in nitrogen

Beef and horse manure tends to be lower in nitrogen

Sheep manure is high in potassium (K)

Different sources of manure have different amounts of nutrients

UNCE, Reno, NV

Cautions for fertilizing with manures

Watch out for weeds and pathogens

Know the manure nutrient content

Consider the salt content

N- P- K

OSU Extension Service

Cautions for fertilizing with manures

Incorporate or apply evenly to avoid smothering plants

Don’t apply on frozen slopes

Avoid leaching nutrients into waterways

UNCE, Reno, NV

What we’ve learned:

Use soil test results to guide you in amending your soil

Nutrient management is more than just adding fertilizers to meet plant needs

Chemical fertilizers and natural or organic soil amendments both have advantages and disadvantages and must be managed based on each farms particular cropping system.

Credits

Presentation adapted from the Living on the Land curriculum, University of Nevada-Reno, Sue Donaldson, et al. 2001

Photos provided by Cultivating Success staff, unless otherwise noted.

Video segment taken from:“Weed ‘Em and Reap, Part 2: Reduced Tillage Strategies for Vegetable Cropping Systems.” Produced by Alex Stone, Oregon State University, Department of Horticulture. Copywrite 2005, Oregon State University.