Improving Life through Science and Technology

The Opportunity to Improve our Situation

Soil for Water

17th July 2015 Fredericksburg, TX

Richard Teague, Texas A&M AgriLife Research, Vernon

Overview

The role of soil in our future

How soil function sustains life

Keys to achieving healthy soil

What to aim for when managing

Managing adaptively for desirable results

Essential Ecosystem Processes

1. Energy flow - Maximize the flow of solar energy through plants and soil.

2. Water cycle - Maximize capture and cycling of water through plants and soil. Reduce export and import.

3. Mineral cycle - Maximize cycling of nutrients through plants and soil.

4. Community dynamics - High ecosystem biodiversity with more complex mixtures and combinations of desirable plant species leads to increased productivity and resilience.

90% of Soil function is mediated by microbes Microbes depend on plants So how we manage plants is critical

Infiltration with Vegetation Composition Thurow 1991

What that looks like….

Indicator: Soil Temperature

At 70 oF, 100% of Soil moisture is used for growth.

At 100 oF, 85% of Soil moisture is lost and 15% is used for growth.

At 115 oF, microbes begin to breakdown, and

At 140 oF they die.

Importance of Fungi

Fungi provide: Access and transport nutrients

Extend root volume and depth

Enhance soil Carbon

Increase water and nutrient retention

Increase drought resistance

Plant growth highest with highest fungal – bacterial ratio

Killham 1994; Leake et al. 2004; Averill et al. 2014; Johnson 2014

Keys to Achieving a Healthy Soil

Minimize mechanical disturbance

Cover the soil surface

Use high plant diversity

Grow plants as many days as possible

Integrate livestock on cropland

Improving Crop and Pasture Soil Health

Improve soil microbe function by: • Perennial plants rather than annuals

• Manage for most productive plants

• Green plants for maximum days each year

• Leave adequate plant residue

• Use diverse species mixes and cover crops

• Eliminate tillage

• Minimize bare ground

• Use organic soil amendments

• Reduce N-fertilizer use

Delgado et al 2011; Rodale 2014; Jones, 2014

The role of forages and grazers

In contrast, ecologically sensitive, regenerative management in crop and grazing agriculture contributes positively to critical ecosystem benefits Conservation management measures and inclusion of perennial forages in cropping systems have been demonstrated to reduce negative impacts

To improve Soil Health

Improve soil microbe population by:

• Keeping the 4 ecosystem processes functioning

• Improving plant cover • Perennial plants rather than annuals

• Manage for most productive plants

• Leave adequate plant residue

• Minimizing bare ground

• Grow plants for as many months each year as possible

Continuous grazing in large paddocks

1. 39% area used

2. 41% GPS points on 9% area

3. SR: 21 ac/cow

4. Effective SR: 9 ac/cow

Many Grass farmers use Adaptive Multi-Paddock grazing successfully

Most conservation award winners use AMP grazing

Planned multi-paddock grazing

Ranch road

Landscape impact of continuous grazing

Existing fence Electric fence

Water point

We turn this desertified land……

Into Productive Land, with Grazing!

Equilibrium of soil formation

and soil erosion

Decreased cover and SOC

Deteriorated soil structure

Decreased infiltration and water

holding capacity

Degradation Spiral

Decreased cover and SOC

We know what causes this at

the small scale

Increased cover and SOC

Regeneration Spiral

Increased cover and SOC

Enhanced soil structure

Enhanced infiltration and water holding

capacity

How to manage for this at the ranch scale?

Thurow 1991

Dimbangombe ranch, Zimbabwe

2006 2009

50 year graze exclosure

Light continuous grazing

2 years of short graze + recovery

All 3 photos taken the same day

Patagonian tussock grassland Annual rainfall 10 “

Patagonia-Fence line contrast with neighbor ranch after 5000 lambing ewes for 50 days (Dec 2011)

Holistic Planned Grazing Continuous grazing at half the stocking rate

High-density grazing

Low-density, light continuous grazing

Managed with Holistic Planned Grazing

No stock for decades

Semi-arid Karroo region in South Africa Average rainfall = 14”

H2O, CO2 H2O, CO2

Why is desertification happening?

Bare ground, a symptom, is caused by:

• Overgrazing and/or Over rest

• Animal Impact for too long

• The world is NOT flat and animals do NOT cause desertification.

• Because we are missing large migratory herds of grazing animals.

Barriers fall away if we acknowledge:

• We cannot manage complexity, only whole systems.

• Different environments respond differently to different tools.

• The grasslands of the world evolved with high disturbance and long recovery ratios.

• Overgrazing is a function of time and not numbers.

Restoration using multi-paddock grazing

Degraded tallgrass prairie 18 paddocks + water point Managed to improve plant species

Noble Foundation, Coffey Ranch

Restoration using multi-paddock grazing Noble Foundation, Coffey Ranch Charles Griffith, Hugh Aljoe, Russell Stevens

Summary of Managing for Desired Outcomes

Plan grazing ahead for different scenarios

Match animal numbers to available forage

Spread grazing over whole ranch

Defoliate moderately in growing season

Short grazing periods

Adequate recovery before regrazing

Graze again before forage too mature

Adaptively change these elements according to changing conditions

Teague et al. 2013

Managing proactively for best results

% Leaf Volume Removed

10%

20%

30%

40%

50%

60%

70%

80%

90%

% Root Growth Stoppage

0%

0%

0%

0%

2-4%

50%

78%

100%

100%

Range Condition Excellent Good Poor

Continuous grazing at Light stocking

Over- and under-grazing side-by-side

Continuous grazing at Light stocking Patch selection and overgrazing

48 Paddocks grazed according to grass growth

Planned multi-paddock grazing Richard’s Ranch Jacksboro, TX

Cattle are moved to a fresh paddock.

High-density grazing

No grazing

High-density grazing

High-density grazing

Light continuous grazing

Successful multi-paddock managers plan grazing and finances to:

Improve spp composition and production

Minimise impact of drought

Reduce costs

Improve work efficiency

Increase profits

Improve quality of life

Managing for Desired Outcomes

Soil microbial communities are fundamentally important to plant productivity There are 4 principles to optimizing microbe benefits 1. Maintenance of year-round living cover, via perennial

pastures on grazed land and/or multi-species cover crop on farmed land.

Almost every living thing in and on the soil depends on green plants for its existence. The more green plants, the more life.

3. Promote plant and microbial diversity.

The greater the diversity of plants the more checks and balances for pests and diseases and the broader the range of microhabitats for the soil organisms involved in nutrient acquisition, nutrient cycling and soil building.

2. Provide support for the microbial bridge, to enhance the flow of carbon from plants to soil.

This requires reducing inputs of high analysis nitrogen and phosphorus fertilizers that inhibit the complex biochemical signalling between plant roots and microbes.

4. The land responds positively to the presence of animals provided management is appropriate.

High intensity, short duration grazing of livestock on perennial pastures is the fastest and most economical way to improve soils.

It adds manure and urine to soils, and increases root exudation and stimulates the number and activity of associative nitrogen-fixing bacteria in the root zone.

This stimulates positive response to defoliation and provides extra nitrogen required by the plant for the production of new growth.

Danglemayr

Pittman

Mitchell

Leo

0 5 10 2.5

Kilometers

Legend

Stream Gage

Clear Creek

Ranch

CCW

Land use

Agriculture

Water

Residential

Bare field

Forest

Rangeland

Clear Creek watershed, north Texas

0.0

0.2

0.4

0.6

0.8

HC LC MP EX

Grazing management scenario

Fra

cti

on

in

to

tal

flo

w

Surface runoff

Groundwater flow

Clear Creek watershed, north Texas

Heavy Continuous Heavy Rotation Light Continuous

Bare

gro

und (%)

Bare Ground

a

b b

P = 0.0006

Heavy Multi-camp

Teague et al. 2011

Soil Carbon, Nutrients and Water

Parameter

Heavy

Continuous

Light

Continuous

Multi-paddock

Soil Organic Matter 3.1b 4.4b 4.86a

Cation Exchange Capacity

24.6b 23.7b 27.4a

Water holding (Gal/acre) 55,700 79,059 87,324

Successful multi-paddocks managers use: Plan grazing ahead for different scenarios

Flexible stocking to match forage availability

Spread grazing over whole ranch

Moderate grazing during growing season

Short graze periods

Allow recovery before regrazing

Graze again before forage too mature

Adaptively adjust to prevailing conditions

Use multiple livestock species

Summary

Appropriate regenerative grazing management:

Sequesters more soil carbon

Improves watershed function

Improves species composition

Improves forage production

Stabilizes soil and soil fertility

Enhances wildlife and biodiversity

Improves economic returns while improving the resource base

Conclusions

END