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Soil Health 101�Farming in the 21^st Century�a practical approach to improve�Soil Health

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Soil Health What is It?

The continued capacity of the soil to function as a vital living ecosystem that sustains plants, animals, and humans

Nutrient cycling
Water (infiltration & availability)
Filtering and Buffering
Physical Stability and Support
Habitat for Biodiversity

This is the definition of Soil health we are using. The term “Health” was purposely chosen instead of “quality”.

Quality implies analysis and quantifying
Health implies management actions that leads to a condition or state, there is something that can be done to change it in a positive trend

The key to the definition is that soil health is:

Continued capacity—implies rejuvenation and then sustainability
Soil is a living ecosystem– folks need to recognize the ground beneath them is a living ecosystem
Soil function – soils need to provide the basic functions below in order for food & fiber production to meet the demands in slide 1

Nutrient Cycling - Soil stores, moderates the release of, and cycles nutrients and other elements. During these biogeochemical processes, analogous to the water cycle, nutrients can be transformed into plant available forms, held in the soil, or even lost to air or water.
Water Relations - Soil can regulate the drainage, flow and storage of water and solutes, which includes nitrogen, phosphorus, pesticides, and other nutrients and compounds dissolved in the water. With proper functioning, soil partitions water for groundwater recharge and for use by plants and soil animals.
Biodiversity and Habitat - Soil supports the growth of a variety of plants, animals, and soil microorganisms, usually by providing a diverse physical, chemical, and biological habitat.
Filtering and Buffering - Soil acts as a filter to protect the quality of water, air, and other resources. Toxic compounds or excess nutrients can be degraded or otherwise made unavailable to plants and animals.
Physical Stability and Support - Soil has the ability to maintain its porous structure to allow passage of air and water, withstand erosive forces, and provide a medium for plant roots. Soils also provide anchoring support for human structures and protect archeological treasures.

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Soil Health Is Understanding How the Soil is Designed to Function and Managing it Accordingly

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Soil is a Living Factory

Macroscopic and microscopic organisms

Food
Water
Shelter
Habitat
Powered by sunlight

Management activities improve or degrade soil health

Tillage
Fertilizer
Pesticides
Grazing
Plant Diversity

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NPK & C

Ray Archuleta

Farm

or

Ranch

Key Points

This slide shows the natural successional progress from agricultural lands through to a steady state climax community,
These will differ across the country but are characterized by having highly functioning ecosystems services, e.g. nutrient, & water cycle and soil food web
Most agricultural lands are characterized by having poor functioning ecosystem services
These services are driven by sunlight
As succession takes place changes occur in the plant communities and soil biota over time, e.g. plants go from annual to perennials,

Nature wants to get to a steady state community

Soil is the integrator between different ecosystems.
Agricultural lands (crop, grazing, etc.) are part of the earth’s ecosystems or biomes
In natural ecosystems, the vegetative cover of a forest or grassland prevents soil erosion, replenishes ground water and controls flooding by enhancing infiltration and reducing water runoff (Perry, 1994).
In agricultural systems, biodiversity performs ecosystem services beyond production of food, fiber, fuel, and income. Examples include recycling of nutrients, control of local microclimate, regulation of local hydrological processes, regulation of the abundance of undesirable organisms.
These renewal processes and ecosystem services are largely biological; therefore their persistence depends upon maintenance of biological diversity (Altieri, 1994).
The net result of biodiversity simplification for agricultural purposes is an artificial ecosystem that requires constant human intervention, whereas in natural ecosystems the internal regulation of function is a product of plant biodiversity through flows of energy and nutrients, and this form of control is progressively lost under agricultural intensification (Swift and Anderson, 1993).

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How do these Ecosystem flourish without human inputs?

Prairie

Forest

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Characteristics of a Stable Ecosystem

Natural Flow of Energy

Bacterial

Fungal

Balanced

High Disturbance

Low Diversity

High Human inputs

Disrupted Eco services

Low Disturbance

High Diversity

Low Human Inputs

Highly Functioning Eco services

Farm or Ranch

Steady State

ecological succession - (ecology) the gradual and orderly process of change in an ecosystem brought about by the progressive replacement of one community by another until a stable climax is established

Natural succession occurs in a plant community and soil communities
Soil that is on the low successional side tends to be dominated by bacteria has high pH and nitrate-nitrogen - a preferred environment for low successional plants (weeds).
Soil on the high successional side have a balanced soil food web, release nutrients in an environment better suited for higher plants.
Each step in the successional process leads towards a steady state community but is held back by natural or man induced disturbance

Characteristics of a Steady (Stable) State Ecosystem

Low disturbance
High diversity in plants, animal and soil biota
Require low human inputs
Have highly functioning eco-services, e.g. nutrient cycling, regulating water and diverse soil food web

Characteristics of an early stage successional ecosystem (farm or ranch)

High disturbance, e.g. physical, chemical and/or biological
Low diversity (monoculture)
Require high human inputs
Have disrupted or non-functioning eco-services

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Disrupted Soil Ecosystem

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

Ray Archuleta 2007

Conventional Soil Ecosystem

This landscape photo could be anywhere in the U.S or across the world, but it shows the current state of soil ecosystems in most of agriculture.
Low successional level and is always kept there due to human activities
Why does Ray say the soil is “Naked, hungry, thirsty and running a fever?”

Bare soil harms the natural system in many ways. Rainfall washes away precious organic matter. Organic matter holds many crop nutrients, and OM is the lightest fraction of the soil and the first to be carried off site.
Bare ground harms the macro and micro organisms…because of lack of carbon (food) in the soil ecosystem. In a bare ground environment, the soil is in starvation mode with no live root to pump carbon (sugars carbohydrates- plant exudates) into the soil system No food means little microbial activity. Important to note: Carbon is the energy (food) source in the system.
Low organic matter reduces the amount of available water for the planned crop, also no cover leads to higher evaporation rates
Bare ground also increases soil temperature, making the soil less hospitable to soil organisms. Temperatures on bare soil can reach above 115 degrees, some microbes start to go dormant at these temperatures.

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�Timpas, Colorado – January 12, 2014�

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Clear runoff from no-till field

No-till field

Conventional-till field

Sediment runoff from conventional-till field

Sediment is still the largest water quality pollutant by volume

Erosion from bare fields into river

Oklahoma October 2012 I-35

Lubbock Texas Oct. 17,2011

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The Battle is Won or Lost Here

Changing our Paradigm

Changing the way we look at the landscape by changing our paradigms
Time to have fun! Use this slide to stress that the soil is on the upland is bare but should instead be covered at all times.
Ask the students.” What is wrong with this picture”? “Or where is the resource concern?”
Participants in the past focused on the stream channel and the buffer strip….rarely did they focus on the bare ground located on the upland. The whole point of this picture is to elucidate the participants about bare ground and our paradigms about the landscape.
Illustrate to the group that unless the ground is covered at all times you cannot expect single practices like buffers strips to prevent non-point pollution.
The main focus: accentuate that the ground should be covered at all times.
The transition photo is from an electron microscope showing what the surface looks like to a depth of 1 mm

Left profile is well aggregated, lots of pore space
Right profile the surface is collapsed and sealed off, no water can enter the soil

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Agricultural soils do not have a water erosion/runoff problem, they have a water infiltration problem.

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Soil Disturbances that �Impact Soil Health

Physical

Tillage
Compaction

Biological

Lack of Plant Diversity
Over grazing

Chemical

Misuse of fertilizer, pesticides, manures and soil amendments

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What is Tillage?

The physical manipulation of the soil for the purpose of:

Management of previous crop residue
Control of competing vegetation (weeds)
Incorporation of amendments (fertilizer/manure)
Preparation of a soil for planting equipment

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What Tillage does to the Soil

Destroys aggregates
Exposes organic matter to decomposition
Compacts the soil
Damages soil fungi
Reduces habitat for the Soil Food Web
Disrupts soil pore continuity
Increases salinity at the soil surface
Plants weed seeds

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CO₂

PHYSICAL DISTURBANCE: Tillage induces the native bacteria to consume soil carbon; byproduct is C0₂.

Tillage Destroys Soil Habitat and Reduces Soils Capacity to Function

Physical disturbance causes native bacteria to consume soil carbon once the soil
This type of disturbance stimulates Zymogenous bacteria (rapid growing bacteria that flourish under nutrient rich environments) and
Autochthonous bacteria (organisms living in soils that contain more recalcitrant material- no abundant supply of easily oxidizable substrate- less food) .
These organisms are stimulated by the influx of oxygen into the soil ecosystem. Once stimulated by the influx of oxygen, these organisms will consume the carbon based glues created by fungi.
SOM is lost as CO2 into the atmosphere
Polysaccharides and other organic compounds bind individual soil particles together into tiny micro-aggregates into larger agglomerations called macro-aggregates. The gooey glyco-protein created by mycorrhizal fungi is called Glomalin and is a very effective cementing agent.
Bacteria also produce polysaccharides and other organic glues as they decompose plant residues. These compounds are very important for keeping the soil pores intact. No soil pores, no porosity, no infiltration.

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Subsoil tillage

Different tillage = Different rates of Carbon loss

Moldboard plow

Chisel plow

3X

2X

1X

Reicosky,2000

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Forest

SOM = 4.3 %

CT 17 yr- Soybean monoculture SOM = 1.6 %

20 cm layer

Management Changes Soil Properties & Capacity of Soil to Function

62.8% loss of SOM after 17 yr intensive tillage

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Study: Use-dependent Soil Properties

Dr. Cathy Seybold, NASS-NRCS

Infiltration rate	Soil Nitrate loss
5o in./hr	1.8 lbs. N/ac.

Infiltration rate	Soil Nitrate loss
.5o in./hr	15 lbs. N/ac.

Conventional Tillage- Corn-Soybean: Bulk Density- 1.40 g/cm³

Wooded Soil: Bulk Density- 1.01 g/cm³

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Effect of tillage on microbial activity

Havlin et al. (1999)

The primary factors controlling microbial activity vary with time

+ SOM

Which tillage system has more microbial activity when crops benefit most from the CO2 and nutrients released by microbial activity?

Soil respiration in CT system

Soil respiration in NT system

CT

NT

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Biological Disturbance

No crop rotation diversity

Growing single species or few crops in rotation
Lack of diversity limits diversity of plant root exudates
Hampers the development of a diverse soil biota

Overgrazing

Plants are exposed to intensive grazing for extended periods of time, without sufficient recovery periods

Disturbance to the soil habitat caused by biological means, we don’t think that miss application of biological activities can have an negative impact on soil health and function

Monoculture – growing a single species or limited number of crops in a planned rotation

Plant exudates attract specific soil microbes, feeding the soil only a limited range of exudates will limit the number of species and different kinds of species in the soil food web
Impacts nutrient cycling, building of soil aggregates and soil organic matter, etc.
Limits the number of functional groups in the soil, e.g. decomposers, photosynthesizers, bacterial or fungal feeders, results in imbalance, diseases, etc.

Overgrazing – exposing plants to intensive grazing for extended periods of time, without sufficient recover periods

Next slide goes into detail as to the impacts

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Reduced root mass
Increased weeds
Reduced soil fungi
Reduced water infiltration
Increased soil temperature
Diminished soil habitat

Biological Disturbance of Overgrazing

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Alternative water sources & controlled access to stream but no control of grazing time on watershed

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Chemical disturbances: over-application of pesticides, fertilizers, amendments & manures

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Soil is a Living Factory

Macroscopic and microscopic organisms

Food
Water
Habitat
Powered by sunlight

Management can improve or degrade soil health

Tillage
Fertilizer
Livestock
Pesticides

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Paradigm Shifts

Paradigm shift #1 Stop treating the symptoms of dysfunctional soil; solve the problem of dysfunctional soil.
Paradigm shift #2 Restoring soil function can be accomplished without going broke.

Apply basic principles of ecology to create quality habitat.
There is no waste in Nature.

Paradigm shift #3 Conservation practices do not restore soil health, understanding soil function restores soil health.

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Clear runoff from no-till field

No-till field

Conventional-till field

Sediment runoff from conventional-till field

Is the Buffer working? 6 /2007

Gabe Brown -ND

Ray McCormick -IN

Dave Brandt -OH

Brandon Rockey -CO

Ray Styer -NC

The principles of soil health apply to all types of farming enterprises, all sizes and all regions of the country

Ray Styer: North Carolina, farms 70 acres of silage corn in rotation with multi speicies cover crop mixes, was an old Tabaco farm, hasn’t used commercial fertilizer in this millennium
Dave Brandt: Corn-Soybean-Wheat farmer from Carroll, OH has been using no-till and cover crops since the 1970’s, had been using a split row planter to seed a row of tillage radish and a legume, has incorporated multi-species cover crops into his system in the last few years.
Gabe Brown: east of Bismarck, ND, 2000+ acres of cropland and 4000 acres of grazing (combination of range and pasture), has reduced his inputs (fertilizer, herbicides, etc.) by greater than 75%. Farms in a 16 inch precipitation area, does not use fallow in his rotation, grazes his cover crops
Ray McCormick: Farms in southern IN along the Wabash river, raises corn and soybean using no till and cover crops. Seeds his cover crops as he is harvesting his crops, has a special seeder attached to his combine that seeds as he is harvesting.
Brandon Rockey, Potato farmer from Colorado, rotates cover crops with potato and companion crops in potato

All of these farmers incorporate soil health planning principles into their farm management.

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Managing for Soil Health

Minimize Disturbance of the soil
Maximize Diversity of plants in rotation/ cover crops
Keep Living Roots in the soil as much as possible
Keep the soil covered at all times with plants and plant residues�
Create the most favorable habitat possible for the soil food web

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All parameters are important; typically we focus on physical and chemical- but Biology is King!

Evaluate How Your

Soil System is Functioning

OM

Typical Agriculture as we know it emphasizes the Physical/Chemical side of the Soil – we ignore the Biological side of the soil.

We are taught to treat the soil system as a machine instead of recognizing it as a living biological system.

WE ARE TAUGHT IN CONVENTIONAL AGRICULTURE REDUCTIONIST SCIENCE – HOW MANY OF YOU WERE TAUGHT THIS WAY IN SCHOOL – You have a weed –kill it –you have a bug Kill it.

We need to step back and use a Holistic view of these systems – tie the dots together and help farmers farm – Learn how to make our soils function! It’s called ECOLOGY!

DID WE CREATE THE PROBLEM/SYMPTOM? DO WE NEED TO CHANGE SOMETHING IN OUR MANAGEMENT TO TRULY CORRECT THESE PROBLEMS?

We need to Farm in nature’s image – We are not here to talk about individual tools (Conservation Practices) that address the symptoms or results of our actions – We start with understanding of how the soil system works. Talk about understanding, then we talk about tools to help us change the soil dynamic properties, those that give us a soil that functions. (this is Conservation Planning (SHMS) – What can be done to improve the soil?

Remember this quote - Nature Acts, Man Argues! (Voltaire) – The Agroecosystem will react to whatever you throw at it.

Typically the chemical and physical have been the major focus for nutrient management, especially in conventional agriculture. We will discuss the Soil Fertility and Crop Nutrient Management in relation to Soil Ecology.

3 Forms of Nitrogen – Ammonium (NH4+), Nitrite (NO2-) and Nitrate (NO3-) and Ammonium –these forms arise either from the normal aerobic decomposition of soil orgnanic matter or from ther additions to the soil of various commercial fertilizers. These 3 forms represent about 2-5% of the total soil nitrogen.

Initially N is in the Ammonium form (NH4), this is converted to Nitrite (by Nitrosomonas) then to Nitrate (by Nitrobacter). This is a Biological Process – not a Chemical Process! As we go from Conventionally tilled Farming to No-Till/Strip-Till Farming – you will go from much available Nitrate in the soil to one that has more Ammonium (NH4). Caused by increase/stability of microbes. Want to solve your incidence of Nitrates getting into the water – work at getting biology back into the soil with Organic Matter and you will increase infiltration – also will increase the Cation Exhange Capacity – which means you will hold more nutrients – this is how to increase fertility of the soil (add carbon which has been depleted) … NH4 is positively charged -

Nitrites must be converted to nitrates because accumulated nitrites are toxic to plant life.

Rhizobium Bacteria have symbiotic relationships with Legume plants. Rhizobium fix Nitrogen – what form of nitrogen comes from Rhizobia? Produce ammonia in exchange for carbohydrates.

Fixes N2 into form the plant can use. Nitrogen is fixed by binding it to hydrogen and making it into ammonia which the legume plant can use. Rhizobia benefit as the plant provides carbohydrates to the rhizobia which are required as a source of energy. The carbohydrate produced by the legume plant are transported to the nodules where they are used by the rhizobia as a source of hydrogen in the conversion of nitrogen to ammonia (NH3).