doug peterson - soil health initiative

31
Basic Soil Health Doug Peterson MO NRCS State Soil Health Conservationist

Upload: john-blue

Post on 15-Jul-2015

114 views

Category:

Environment


1 download

TRANSCRIPT

Basic Soil Health

Doug Peterson MO NRCS State Soil Health Conservationist

How do we define a health soil?

A healthy soil:

• has a stable soil surface,

• is increasing in SOC or is at the maximum level for the location,

• has a microbial population that efficiently decomposes organic residues,

• does not contain P, N, or herbicides and pesticides in sufficient quantities to cause water quality problems in the event of an unexpected erosional episode

• is regenerative under its intended land use or management system.

Is our soil unhealthy?

What is the “Canary in the Mine” of the Soil ?

What do most of our soil tests show today?

What really determines the potential Soil Organic Matter in a given area?

4

0 20 40 600

25

50

75

100

Carb

on c

onte

nt %

Reduction in the Carbon content of the soil with time of soil use

Years under tillage cultivation (Bauer & Black, 1983)

%

North Dakota Farm Research

What is the most limiting natural resource in your forage/crop production system?

Sunshine?Minerals?

Water?

What is the most important item in the water cycle???

The Water Cycle-Is it broken?

Monday, June 12, 2006 8:30am Rainfall: 1.8 inches

Disk No Cover Disk Cover

No Tillage CoverNo Tillage No Cover

JSWC C.W Raczkowski 2009

CT= 119 tons/6 years89% lost in 3 rain events (June 97, June 2000 and Sept 2000

NT= 7.1 tons/6 years

3.8%-6.2% slopes

6 year study

Forest SOM = 4.3 %

CT 17 yr- Soybean monoculture SOM = 1.6 %

20

cm

la

yer

This is the same soil- What happened?

Both soils started with the same Inherent soil Properties soil:

•climate (precipitation and temperature) •topography (shape of the land) •biota (native vegetation, animals, and microbes) •parent material (geologic and organic precursors to the soil) •time (time that parent material is subject to soil formation processes)

62.8% loss of SOM after 17 yr intensive

tillage

Dynamic properties depend both on land management and inherent properties of the soil: • organic matter,• soil structure, • infiltration rate, • bulk density, • and water and nutrient holding capacity.

62.8% loss of SOM after 17 yr intensive

tillage

Disrupted Soil Ecosystem

This soil is naked, hungry, thirsty and running a fever!

Ray Archuleta 2007

When soil temp reaches. . .140°F

130°F

100°F

70° F

Soil bacteria die

100% moisture lost through evaporation & transpiration

15% moisture is used for growth 85% moisture lost through evaporation & transpiration

100% moisture is used for growth

J.J. Mc Entre, USDA SCS, Kerrville, TX, 1956

Physical Disturbance in the form of tillage destroys the

biological and ecological integrity of the soil ecosystem.

1. Disturbance stimulates the first responders--increased weed population

2. Destroys soil pores by shearing and smashing-impacts infiltration

3. Diminishes the soils ability to respire

4. Disrupts the habitat of most microorganisms arthropods

5. Simplifies the soil fauna over time -fungi don’t like disturbance -Mycorrhizal fungi – uptake of P, Zn, Cu, Fe

13

Mineralisation of Organic Matter

>Erosion

Consequences of tillage

The USDA estimates that about half the fertilizer used each year in the US simply replaces soil nutrients lost by topsoil erosion.

(David Montgomery, 2007)

What is the primary reason given for tillage?

Nature’s residue managers

See Video Clip

No-till Systems are the Beginning of Cropland Soil Health

25 yrs of conventional corn

20 yrs of bluegrass, then 5 yrs conventional corn

Water stable

aggregates

After adding water

Soil Health

Type of Organism number/acre pounds/acre

Bacteria 800,000,000,000,000,000,000 2,600

Actinobacteria 20,000,000,000,000,000 1,300

Fungi 200,000,000,000,000 2,600

Algae 4,000,000,000 90

Protozoa 2,000,000,000,000 90

Nematodes 80,000,000 45

Earthworms 40,000 445

Insects /arthropods 8,160,000 830

Soil Food Web

Ex

ud

ate

s

SoilRoot

Rhizosphere

Rhizosphere

Number one food source of most soil organisms is a living root.

Living roots release many types of organic materials into the rhizosphere around the surface of the root

Rhizosphere

The number of organisms in the rhizosphere is up to 2000 times higher than in the rest of the soil.

Plants Interacting with Mycorrhizal Fungi

Assists with P uptake from the soil

Moves P from the non-legume plant to the legume plant

Moves N from the legume plant to the non-legume plant

The Nature and Property of Soils, Brady and Weil

Restoration Through Soil Health

Ranching/Farming in the 21st Century-a practical approach to soil health

Manage more by disturbing less

Diversity is Critical

Living Roots feed your soil livestock

Keep the soil covered

Integrate livestock

The quality of our lives depends on

the food we eat

the water we drink

and the air we breath.

The quality of our lives depends on

the food we eat

the water we drink

and the air we breath.

All of those things depend on

the quality of the SOIL.

Charles Kome

Expand your knowledge - Read a Book

The Nature and Properties of Soils by Brady and Weil

Holistic Management by Allan Savory

Agroecology by Gliessman

The One Straw Revolution by Masanobu Fukuoka

Teaming with Microbes by Lowenfels and Lewis

Soil Biology Primer by Elaine Ingham

The Worst Hard Times by Timothy Egan

Collapse by Jared Diamond

Dirt-The Erosion of Civilization by David Montgomery