Transcript Administrative Update - Colorado State University

Developed by:
Hudson Minshew
Oregon State University Extension Service
Susan Donaldson
University of Nevada Cooperative Extension
NRCS, Bozeman, Mont.



What do my soil test results mean?
What nutrients do plants need?
How can I supply those nutrients?




Indicates relative acidity or alkalinity
= pH 7 => neutral;
< pH 7 => acid;
> pH 7 => alkaline or basic
Adapted from library.thinkquest.org by A. Miller
CO Soils generally 7.0-7.8
Western CO Valley Soils generally 7.5-8.5
Adapted from www.soil.ncsu.edu by A. Miller
Widest part of the bar indicates maximum availability




Acid soils: pH is below 7
Soils become acid due to 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



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




Alkaline soils: pH is above 7
Soils that have not been greatly
weathered or leached
Soils high in calcium
Reduces solubility of all micronutrients
Adapted from library.thinkquest.org by A. Miller
Example of crop grown in
alkaline soil
http://ag.arizona.edu
Adapted from ag.arizona.edu by A. Miller

A measure of inorganic
chemicals that are more
soluble than gypsum,
such as:
◦
◦
◦
◦
◦
◦

USDA NRCS
sodium,
calcium,
magnesium,
chloride,
sulfate,
bicarbonate.
Salty soils are a problem in
arid regions or in poorly
drained soils



Electrical conductivity measurements (EC)
Exchangeable sodium percentage (ESP)
Salt-affected soils are commonly
classified for management purposes into
three groups based on EC and ESP:
◦ saline,
◦ sodic, and
◦ saline-sodic
Grand Valley, CO




Select plants that can tolerate salinity
Avoid excess or salty forms of fertilizers
Incorporate organic matter
If appropriate, add sulfur to lower the pH

In soils with good drainage, periodically
leach the salts below root zone with high
quality irrigation water (avoid if high water
table present)




Substances necessary for plant growth
Some, such as hydrogen, oxygen and
carbon, come from the air and water
Others, such as nitrogen and phosphorus,
may need to be added
Excess or improper use of fertilizers may
result in water pollution
BIG 3
N = nitrogen
P = phosphorus
K = potassium
H = hydrogen
O = oxygen
C = carbon
Fe = iron
Mn = manganese
Zn = zinc
B = boron
Mb = molybdenum
Ca = calcium
Mg = magnesium
S = sulfur
Ni = nickel
Cu = copper
Co = cobalt
Cl = chlorine
1.
2.
3.
4.
5.
6.
Which elements do I need?
(N, P, K, S, Ca)
How much do I apply?
What type of material do I use?
Which application method is best?
When is the best time to apply it?
Will I get a return on my investment?


Chemical fertilizers
Organic fertilizers (bone meal, compost,
manure, etc.)
www.farmphoto.com
WAY TO GROW
FERTILIZER
28 – 14 - 5
GUARANTEED ANALYSIS
Total nitrogen
6% Ammonium nitrogen
14% Urea nitrogen
Available phosphoric acid
Soluble potash
28%
NPK formula
Nitrogen content
14%
5%
Derived from sulfur-coated urea,
etc.
Product name
Phosphorus content
Potassium content
Specific sources


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 1,000 square
feet, or pounds per acre
To convert a
recommendation to
pounds/acre of an actual
fertilizer material, use the
following formula:
Pounds of nutrient recommended X 100
Percentage of nutrient in fertilizer
material


Length x Width = Area
If the area is oddly shaped or oval, calculate
using a regular shape that closely fits the
shape of the land to be fertilized
200 ft
150 ft
100 ft
150 ft



Good source of
nutrients and
organic matter
Protects soil
from raindrop
impact and
erosion
Local supply
often available
at no cost
OSU Extension Service



UNCE, Reno, Nev.
Poultry manure is
high in nitrogen
Beef and horse
manure tends to
be lower in
nitrogen
Sheep manure is
high in potassium



Watch out for
weeds and
pathogens
Know the
manure
nutrient
content
Consider the
salt content
Univ. of Oregon



Incorporate or
apply evenly to
avoid
smothering
plants
Don’t apply on
frozen slopes
Avoid leaching
nutrients into
waterways
UNCE, Reno, Nev.
Nutrient deficiencies
•Nitrogen
•Phosphorus
•Potassium
•Calcium
•Zinc
•Manganese
USDA NRCS



Use soil test results to guide you in
amending your soil
Test results are only as good as the
sample you collect
Fertilize to meet plant needs, and avoid
costly overuse that may pollute water
How to use a soil survey
 How to find a map unit
 Map unit descriptions
Soil ratings and capabilities


http://websoilsurvey.nrcs.usda.gov


A map unit
describes a soil
“type” in the soil
survey
“Map-unit
descriptions” are
found at the
beginning of the
survey
630 Fleischmann
gravelly clay loam
Number
designation
Soil
textural
class is
part of
map unit
name
Name given by soil
scientists conducting
survey
NRCS, Bozeman, Mont.
Suitability ratings
 Freeze dates and growing season
 Productivity (tons/acre)
 Building site development
 Suitability for irrigation
 Physical and chemical properties

◦ (percent OM, pH, available water capacity)
Soil surveys can differ in the
information they provide.







Cemented pan
Droughty
Erodes easily
Flooding
Low strength
Restrictive layer
Shrink-swell
potential
UNCE, Reno, Nev.
Classes
 I and II - good farmland with few to
moderate limitations
 III and IV - severe to very severe limitations
for growing crops
 V and VI - limitations that are impractical
to remove.
 VII and VIII - very severe, unsuited for
cultivation.
USDA NRCS

Soil surveys are generated by NRCS scientists

Available in printed form or on the Web

Soil surveys are useful for determining
capabilities and limitations of your soils at the
large scale.