# Presentation: 507801

## Farming and Soil Quality

- No Till Benefits

## “Out of the long list of nature’s gifts to man, none is perhaps so utterly essential to human life as SOIL.” H. H. Bennett 
“The nation that destroys its soil destroys itself PERIOD.”  Pres. Franklin D. Roosevelt

- “Out of the long list of nature’s gifts to man, none is perhaps so utterly essential to human life as SOIL.” H. H. Bennett
- “The nation that destroys its soil destroys itself PERIOD.”  Pres. Franklin D. Roosevelt

**Notes:**
Here I am preaching to the choir – NRCS and SWCD employees must believe in the importance of soil.

These quotes were made in the “Dirty Thirties” by some far seeing people about the soil resource that we are here to protect. 

## Tillage is the norm
Soil erosion 2T (acceptable not sustainable)
Short term rotations (corn-soybeans)
Weed control with glyphosate
Fall tillage operations desired
Larger equipment for tillage and harvest
Early planting dates desired

- Tillage is the norm
- Soil erosion 2T (acceptable not sustainable)
- Short term rotations (corn-soybeans)
- Weed control with glyphosate
- Fall tillage operations desired
- Larger equipment for tillage and harvest
- Early planting dates desired

**Notes:**
No till increased in Missouri in the early 1990’s but is now decreasing do to “problems” (perceived).

The national Food Security Act through the current farm bill allows farmers to receive benefits while soil erosion exceeds 2 times the sustainable level – T value.  This is not acceptable if soil quality is a goal.

Perennial crops are rarely grown in rotation.  A simple corn soybean rotation is now the norm.

Roundup is the herbicide of choice especially for genetically modified crops.  Not real effective on small weeds under tall stubble.  No residual effect of Roundup on weeds germinating later.  Farmers tend to delay weed control until weeds are up and bigger.

Fall tillage to reduce surface residue and allow earlier spring warm-up is now common.

Equipment is now very large – cover more acres in less time for efficient operation.

Farmers want to get the crops in before rain delays.  The earlier the better appears to be the current motto!

## Soil moisture loss
Reduced soil organic matter
Soil exposed to wind and water erosion
Soil aggregates and structure  destroyed  

- Soil moisture loss
- Reduced soil organic matter
- Soil exposed to wind and water erosion
- Soil aggregates and structure  destroyed

**Notes:**
In the past farmers:
Tried to grow crops on marginal soils in marginal climates with intensive tillage.  Better  agronomic understanding still allows crop production in these areas with proper farming (fallow) operations.

Tillage reduced soil OM and the binding material for marginal soils.  Water and wind erosion were common events.  Black Sunday – April 14, 1935

Residue was removed leaving soil exposed to nature’s wrath – wind and water erosion were severe!

Excessive tillage destroyed soil aggregates and soil structure.  Particles loosened by tillage were more subject to wind and water erosion.

Remember that soil erosion is a condition of permanent impoverishment!
Any loss is NOT acceptable from an agronomic perspective.

## Reduced waterstorage
Reduced waterinfiltration
Loss of topsoiland production

- Reduced waterstorage
- Reduced waterinfiltration
- Loss of topsoiland production

**Notes:**
The intensive tillage on marginal soils oxidized OM and reduced the potential water storage in soils.  There was also a reduction in the rate soils accepted water due to this tillage (OM and macropores were destroyed).  Rains on bare soil dissipated soil particles plugging surface mico and macro pores.

The most severe effect was the loss of topsoil to erosion.  Production decreased with the loss of the good topsoil.  Runoff increased without topsoil for infiltration.  Drought conditions were exacerbated with the topsoil loss.

## No till acreagedecreasing in Missouri
Continuous no tillis hard to find
Convenience not a commitment

- No till acreagedecreasing in Missouri
- Continuous no tillis hard to find
- Convenience not a commitment

**Notes:**
No Till sure can be the answer.  However, the acreage in true no till is decreasing in Missouri due to problems with planting early.  No till fields are wetter and cooler on the surface than comparable tilled fields.  Planting operations often result in compaction in the seed row and poor germination.

Continuous no till is now practiced by the truly dedicated farmer.  No till allows the farmer to cover more acres than conventional methods.  But conditions have to be right to make the no till operations successful.  Residue needs to be managed prior to planting.  The soil surface needs to be dry enough for proper planting.

No till is often a convenience to be used only when all other methods have failed in spring time in Missouri.  The conditions are not great for no till be are usually impossible for normal planting methods.  We need to have a commitment to no till to get it to grow and survive in Missouri.

## Improved Soil Quality- Erosion control (wind and water)- Good soil organic matter- Good soil structure- More infiltration- Less compaction- Less crusting

- Improved Soil Quality- Erosion control (wind and water)- Good soil organic matter- Good soil structure- More infiltration- Less compaction- Less crusting

**Notes:**
Soil Quality should be our goal.  A healthy, productive soil is desired and achievable with no till.  Some of the desired benefits are:

Erosion Control – rill and interrill (sheet and rill) erosion is reduced.  Results in cleaner water and cleaner air.
Soil Organic Matter – Tillage burns soil organic matter.  No till is one method to get the OM back into the soil.
Soil Structure –  structure returns overtime with aggregate stability.
Infiltration – improves due to micro and macro pore development, result is less runoff and more beneficial water available to crops.

Compaction – natural consolidation of soil is resistant to major compaction.

Crusting – soil surface particles are not dispersed by raindrop impact; crusting is not a problem.

## Water Quality- Less sediment- Nutrientsand pesticides stay in place
Air Quality- Less soil particulate matter- Less odors

- Water Quality- Less sediment- Nutrientsand pesticides stay in place
- Air Quality- Less soil particulate matter- Less odors

**Notes:**
Using no till to reduce rill and interrill erosion usually results in a reduction in sediment, nutrient, and pesticide losses.  No till will have cleaner water runoff than conventional no till.  A drop striking earth splashes as muddy water; a drop striking residue splashes as clear water and the splash settles to earth as a gentle spray.

Residue also reduces particulate matter losses from wind events or from tillage operations.  The wetter environment of no till also reduces the particulate losses.

Odors – residue cover and higher moisture of no till also have a positive effect on the control of odors.  No till fields are a great place for application of organic manure materials.

## AnimalsFood and cover     for wildlifeDiversity of animal     life
PlantsSoil moistureSeedling protection

- AnimalsFood and cover     for wildlifeDiversity of animal     life
- PlantsSoil moistureSeedling protection

**Notes:**
Excellent cover and food source for a variety of animals.

Residue management conserves moisture (about 1 inch for each tillage operation that does not occur).  Tillage dries the soil to the depth of the operation.

Residue protects emerging seedlings from desiccation by winds and sunlight.  Also protects from the abrasion of wind blown particles.

## Important indicator of soil quality
“Burned” with tillage – releases CO2
Crowns and root structure is major source
Positive effect on CEC
Energy source for soil “critters”
Moisture storage

- Important indicator of soil quality
- “Burned” with tillage – releases CO2
- Crowns and root structure is major source
- Positive effect on CEC
- Energy source for soil “critters”
- Moisture storage

**Notes:**
OM is influenced by temperature, moisture, tillage, vegetation, slope, aspect, and soil texture.

OM is 58 percent carbon and 5 percent nitrogen.  Carbon comes from the air as CO2 (a greenhouse gas that is a global concern).

More OM on grassland soils than on forested soils.

Greater OM in finer textured soils.  Maximum amount of humus related to percentage of clay.

Poorly drained soils have higher OM.  Poor aeration inhibits OM destruction.

Cultivated land contains lower levels of OM and N than comparable areas with natural vegetation.

Soil physical properties – dark brown color, influence on granulation and aggregate stability, reduces plasticity, cohesion, and stickiness.

Soil chemical properties – accounts for 50 to 90 percent of CEC if mineral soils, buffering action, and humic acids accelerate mineral decomposition.

Soil biological properties – OM affects type and diversity of soil organisms present and the rates of decomposition.

## Fate of Organic Matter

**Notes:**
Rapid decline of OM content with cultivation.  Mixing air with soil high in OM results in a rapid oxidation of the C and release by respiration.

OM reaches a new but lower equilibrium level.

New OM level is dependent on crops grown and management used on the soil type.

Easier to maintain high productivity on soils high in OM compared to low OM soils.  More forgiving for mistakes or variances in weather.

## 45-50% passive OM fraction
30-35% slow oxidized OM
About 15% active oxidized OM
About 10% plant residues

- 45-50% passive OM fraction
- 30-35% slow oxidized OM
- About 15% active oxidized OM
- About 10% plant residues

**Notes:**
Active and Slow fractions (about 50 percent of soil OM in native state) respond most quickly to management changes.

More productive soils have higher proportions of the active fraction of OM.  This probably even increases with as we travel north to colder yet still productive areas (Minnesota) where soil temperatures are not as high as in Missouri.  And the inverse may also be true – OM decreases as we go south to warmer soils.

Active pool very important in aggregate stability and N mineralization.

Management changes that result in small changes in total OM may have pronounced changes in aggregate stability and N mineralization rate due to the effect on the active fraction.

Little change in OM at depths greater than 9 inches.  In general OM decreases with depth.

## 80 to 90% passive organic matter
Less than 10% slow oxidized OM
Less than 2% fast oxidized or plant residues 
Anticipated Trend – continue to slowly decrease OM for the long term, fairly steady on the short term
No till or hay needed to improve OM

- 80 to 90% passive organic matter
- Less than 10% slow oxidized OM
- Less than 2% fast oxidized or plant residues
- Anticipated Trend – continue to slowly decrease OM for the long term, fairly steady on the short term
- No till or hay needed to improve OM

**Notes:**
Must continuously add supply of organic materials – roots and plant crowns are most important, but manure can be an important source of OM.

Carbon sequestering may be economic benefit for the farmer (CO2 is estimated at 49 percent of the contribution to global warming).

Maintain sufficient levels of N for maximum growth.

Maintain maximum plant growth to increase OM amount added to soil.

Minimize tillage to minimize OM oxidation.

Encourage and maintain perennial vegetation when possible in the rotation.  Perennial vegetation roots deeper than annuals.

## Disking causes greatest CO2 losses(greater soil mixing)
Disking deeper and running faster caused higher CO2 losses
Chisel plowing losses less than disking
Fall till losses higher than spring till

- Disking causes greatest CO2 losses(greater soil mixing)
- Disking deeper and running faster caused higher CO2 losses
- Chisel plowing losses less than disking
- Fall till losses higher than spring till

**Notes:**
Moldboard plowing can often bury residue at depths that limit decomposition.  On irrigated fields, I have seen residue that was buried with a plow in September pulled to the surface with root harvesting methods the following September that was as bright and shiny as the day it was buried.  The residue is basically twisted into a tube of material and buried far from the air needed for oxidation.  This is not a desired condition.

However, if the fields were disked the small grain residue was gone by the following June.  The mixing action of the disk with air at the surface results in fast oxidation of the residue.

## OM has significantly decreased from native state
Erosion still a major factor
Decrease tillage to build OM (no till or minimum till)
Slow response to management, 10 to 15 years for a notable change on soil test
Active OM and slow OM respond fastest to management changes (either up or down)
Changes to aggregate stability and N mineralization

- OM has significantly decreased from native state
- Erosion still a major factor
- Decrease tillage to build OM (no till or minimum till)
- Slow response to management, 10 to 15 years for a notable change on soil test
- Active OM and slow OM respond fastest to management changes (either up or down)
- Changes to aggregate stability and N mineralization

**Notes:**
Use no till or minimum till as continuous practices – one intensive mixing tillage will “burn” OM and release carbon.  All is lost with one intensive tillage operation.  Use no till or minimum till as continuous practices to maintain positive benefits.

The best OM comes from plant crowns and roots.

Over time soil aggregates and N mineralization improves.

## Go beyond “T” and manage for “C”
Carbon, OM, and soil quality are becoming more important environmentally and agronomically
Carbon sequestration

- Go beyond “T” and manage for “C”
- Carbon, OM, and soil quality are becoming more important environmentally and agronomically
- Carbon sequestration

**Notes:**
“T” value has been a goal for NRCS since the Dirty Thirties.

In my career “T” became important in 1985 with the Food Security Act.  T was the goal to reach for conservation compliance.  We also had alternative conservation systems due to economic reasons that became the 2T level used today.

Prior to 1985 we planned for soil quality using a soil conditioning index.  

The soil conditioning index considered:
	ER - erosion losses or topsoil removal
	Field operations (FO) – number, depth, and intensity of tillage and additions such as fertilizer, limestone, and manure
	Organic matter (OM) – yield, residue production, rooting depth, and rotation

Each factor had a corresponding value either positive or negative.  Merely adding and subtracting gave you an index value.  If you had a positive soil conditioning index, there was never a problem with soil loss and the T value.

## Residue reduces sheet and rill erosion- reduces splash effect (dissipates energy)- retards runoff- increases infiltration
Gully erosion- consolidated soil less likely to erode- gullies are narrower and deeper

- Residue reduces sheet and rill erosion- reduces splash effect (dissipates energy)- retards runoff- increases infiltration
- Gully erosion- consolidated soil less likely to erode- gullies are narrower and deeper

**Notes:**
Clear water is the desired runoff from no till fields.

Notice no mention of ephemeral gully erosion.  Ephemeral is short-lived or temporary.  Any gully erosion in no till is not temporary or short-lived unless remedial treatment occurs soon after development.  There no longer is periodic tillage to cover the ephemeral gullies and rills.

Soil consolidation occurs in about 5 to 7 years on soils in the Midwest.  Consolidation takes longer in drier climates.

## Higher wind velocity threshold
Consolidated soil
Soil structure

- Higher wind velocity threshold
- Consolidated soil
- Soil structure

**Notes:**
Discuss the dynamics of wind erosion.  The threshold velocity of 13 miles per hour and particle size.

Note that the clumps of perennial vegetation are resistant to wind erosion.  Note the roots and soil structure in the sandy materials that appears to be resistant to the wind forces.

The erosion losses appear to be about 4 feet of topsoil and subsoil.  The damage has occurred at the site of erosion (origin) and also as deposited materials.

## Soil structure
Slowed runoff
Undisturbed macropores

- Soil structure
- Slowed runoff
- Undisturbed macropores

**Notes:**
Already discussed soil structure and benefit of glomalin.

Good infiltration is desired.  Want the water that falls on the land to stay on the land.

Macropores from soil fauna and residue are a major pathway for infiltration.

## Desired surface structure- granular and friable- high organic matter- high infiltration
Desired subsurface structure- soil consolidation- aggregate stability- water holding capacity

- Desired surface structure- granular and friable- high organic matter- high infiltration
- Desired subsurface structure- soil consolidation- aggregate stability- water holding capacity

**Notes:**
Soil surface must be in a condition to accept water infiltration:  less runoff and erosion; less surface ponding; surface does not stay saturated.

## Slide 21

**Notes:**
The previous slide generally makes you think that plants are the most important living organism in the soil.  This slide shows the plants and animals interacting to provide a healthy ecosystem.

Animals account for macro-pores in the soil.

Generally, the animals tend to feed on plants or other animals.  Certain plants or plant-like organisms will also feed on animals such as nematodes.  Microscopic filaments have been seen to entangle and snare nematodes in the soil system.

## Arbuscular mycorrhiza (AM or VAM) predate evolution of roots and land plants
Asteroxylon spp. - 460M year old fossil
Glomales spp. (about 300 species) important to soil structure- need plants for energy (carbon)- must grow on plants to survive

- Arbuscular mycorrhiza (AM or VAM) predate evolution of roots and land plants
- Asteroxylon spp. - 460M year old fossil
- Glomales spp. (about 300 species) important to soil structure- need plants for energy (carbon)- must grow on plants to survive

**Notes:**
Symbiotic relationship between fungi and plants.  Carbon source supplied by the plant as fungi do not contain chlorophyll.  In return the fungi supplies water and nutrients to the plant.

Natural or native areas contain abundant mycorrhizal fungi.  About 85 to 90 percent of plant species benefit from the fungi.   Disturbed areas lack this beneficial fungi – tillage, compaction, erosion, mixing of topsoil, land clearing, and pesticide use are all adverse to fungi development.

## Develops mycorrhiza finer than root hairs
Thoroughly penetrates soil
Supplies some nutrient/water for plant
Growth rate of plants increase
Diversity of soil fungi varies with diversity of plants

- Develops mycorrhiza finer than root hairs
- Thoroughly penetrates soil
- Supplies some nutrient/water for plant
- Growth rate of plants increase
- Diversity of soil fungi varies with diversity of plants

**Notes:**
The fungi penetrates the surface of a live root and attaches.  With the energy from the growing plant hyphae are extended through the soil particles.  Hyphae are finer than root hairs and extend further into the soil medium.

## Glomales mycorrhiza produce glomalin
Glomalin - a sticky protein substance
Binds soil particles together
Major contributor to soil structure 
Stores one-third of soil carbon
Glomales spp. adversely affected by annual cropping 

- Glomales mycorrhiza produce glomalin
- Glomalin - a sticky protein substance
- Binds soil particles together
- Major contributor to soil structure
- Stores one-third of soil carbon
- Glomales spp. adversely affected by annual cropping

**Notes:**
Glomalin is a protein compound recently discovered in soils.  This protein is produced on the surface of hyphae that are being extended through the soil.  This material is resistant to degradation – lasts from 7 to 42 years in soil.  Rate of degradation is based on temperature and moisture conditions.  

## Geosmin (C12H22O)- smell produced by fungi and bacteria as OM breaks down- pleasing, earthy smell of a healthy soil- bad taste in water or wineFact:  the smell that camels follow to find an oasis in the desert

- Geosmin (C12H22O)- smell produced by fungi and bacteria as OM breaks down- pleasing, earthy smell of a healthy soil- bad taste in water or wineFact:  the smell that camels follow to find an oasis in the desert

**Notes:**
Have you ever smelled a healthy soil in good hydraulic condition.  One that is loaded with earthworms, humus, roots and moisture.  It is a smell that you will forever remember; a smell that shows all is right with your soil.  You are smelling geosmin, a byproduct of the breakdown of OM.

## Slide 26

**Notes:**
A healthy soil ecosystem includes the plants and animals that live and die in the soil along with the pores, burrows, and holes that are needed for roots and animals to live.  This is definitely a complex ecosystem.

## Earthworms, tardigrades, and other critters
Feed on microflora, other micro or macro fauna, or organic matter
Hidden conduits of burrows and tunnels aerate  the soil

- Earthworms, tardigrades, and other critters
- Feed on microflora, other micro or macro fauna, or organic matter
- Hidden conduits of burrows and tunnels aerate  the soil

**Notes:**
“I am telling you this story,” said Father Worm, rather testily.  “So just put a fish hook in that mouth of yours and let me finish!  Now where was I?  Oh, yes!”

Let’s look at some of the critters that make soil their home.  Tardigrades (little water bears) are insect-like.  Some 700 species have been identified in the soil ecosystem.  Other critters are springtails, ants, termites, voles, moles, gophers, skunks, badgers, etc.

All these critters in one form or another are common in natural soils but may be lacking in cultivated soils.  Why??

Let’s talk of the mighty earthworm:
Want about 5 different species that are shallow-dwelling and one deep-burrowing species in the Midwest.
Goal of 1 ton of earthworms per acre (about 25 per square foot) or nearly 1 million per acre.
This is your earthworm herd that will require food and proper living conditions.
You will need about 1100 miles of burrows per acre (horizontal and vertical combined).
Equal to about 2000 feet of 6 inch tile per acre (1 every 20 feet across the field)!

##   “The plow is one of Man’s ...most valuable inventions, but long before he existed, the land was in fact regularly plowed and still continues to be thus plowed by earthworms.”- Charles Darwin, 1881

Earthworm Fact:  longest earthworm ever recorded was 22 feet long in South Africa

-   “The plow is one of Man’s ...most valuable inventions, but long before he existed, the land was in fact regularly plowed and still continues to be thus plowed by earthworms.”- Charles Darwin, 1881
- Earthworm Fact:  longest earthworm ever recorded was 22 feet long in South Africa

**Notes:**
Earthworms:
- Incorporate crop residue, fertilizer and soil amendments.
Increase water infiltration.
Increase water holding capacity.
Increase availability of P and K
Live up to 9 years if they don’t go fishing with you!
Deposit 20 to 40 cocoons per year as offspring (still viable after 40 years)
3000 species in the world
Highest populations in soils with surface residues
Legumes much better for earthworms than grain crops
Populations increase with manure applications
Plowing kills 20 percent and removes food source from surface.
Very toxic – Thimet, Sevin, Furadan, Chloropicrin
Moderate toxic – Dyfonate, Counter, simazine
Slightly toxic – Diazinon, 2,4-D, Malathion
Non-toxic – glysophate, atrazine
Anhydrous ammonia and ammonium sulphate are toxic
Bacteria and actinomycetes live in burrows and give it a healthy smell

## Conventionally tilled corn-soybean rotation- 0.6 inches per hour (Armstrong map unit)
Long term no till corn-soybean rotation- 3.2 inches per hour (Armstrong map unit)
Native prairie- 5.8 inches per hour (Mexico map unit)

- Conventionally tilled corn-soybean rotation- 0.6 inches per hour (Armstrong map unit)
- Long term no till corn-soybean rotation- 3.2 inches per hour (Armstrong map unit)
- Native prairie- 5.8 inches per hour (Mexico map unit)

**Notes:**
“Except for the oceans there is no reservoir so vast and effective as absorptive soil.”  H.H Bennett, July 25, 1936

## Common with today’s larger equipment
Tillage compaction when wet
Shear zones of past tillage
Solved with deep vertical tillage and managed traffic

- Common with today’s larger equipment
- Tillage compaction when wet
- Shear zones of past tillage
- Solved with deep vertical tillage and managed traffic

**Notes:**
Shear zones or plow soles – that compacted area where tillage equipment cuts the soil.  Must use vertical tillage to rip or bust this zone.

Soil surface that ephemeral gullies erode down to!

Anhydrous ammonia dissolves the soil binding compounds (glomalin) leading to weak soil structure.

## Surface bulk density increases
No tillage to loosen surface and add air
Let nature run its course – OM increases and soil structure improves in 3 to 5 years
Remove subsoil compaction before conversion to continuous no till

- Surface bulk density increases
- No tillage to loosen surface and add air
- Let nature run its course – OM increases and soil structure improves in 3 to 5 years
- Remove subsoil compaction before conversion to continuous no till

## Problem on low OM soils with no surface cover
Raindrops disperse soil particles and seal the surface
Dries to a crust
Crusts restrict emergence of crop 
No Till – OM, surface residue, and soil aggregate stability limit crusting

- Problem on low OM soils with no surface cover
- Raindrops disperse soil particles and seal the surface
- Dries to a crust
- Crusts restrict emergence of crop
- No Till – OM, surface residue, and soil aggregate stability limit crusting

## Reduce soil erosion and runoff to reduce concerns
Increasemacropores

- Reduce soil erosion and runoff to reduce concerns
- Increasemacropores

## Part of RUSLE2
Estimate trends in soil quality
(+) trend desired
Change crops,tillage, or managementto affect SCI value

- Part of RUSLE2
- Estimate trends in soil quality
- (+) trend desired
- Change crops,tillage, or managementto affect SCI value

**Notes:**
New and improved SCI within the RUSLE2 model.

Calculated from the data entered into RUSLE2.  Subfactors are:
	Erosion
	Field Operations
	Organic Matter

## Evaluates ground contact passes for kind, severity, and number
Considers speed, tillage type, tillage depth, and percent disturbance
CSP program requires STIR = 30 or less for first level of funding

- Evaluates ground contact passes for kind, severity, and number
- Considers speed, tillage type, tillage depth, and percent disturbance
- CSP program requires STIR = 30 or less for first level of funding

## Slide 36

## Slide 37

## Slide 38

## Slide 39

## Slide 40

## Slide 41

## Among others in a 
healthy soil system!

- Among others in a
- healthy soil system!