Agronomy-Driven Improvement Dennis Chessman USDA Natural Resources - - PowerPoint PPT Presentation

Soil Health Assessment and Agronomy-Driven Improvement

Dennis Chessman USDA – Natural Resources Conservation Service, Soil Health Division June 27, 2018

The diverse underground world

Drawing Credit: SESL, Australia

Healthy soils have diversity and abundance of life

Medicinal Breakthroughs Fights disease and pests

In general, soils converted to crop production demonstrate:

• decreased water

infiltration & storage

• less biological activity
• lower biological diversity
• less efficient nutrient

cycling

• less C sequestered
• higher summer

temperatures

• less contribution to plant

vigor

• lower stress resistance

and resilience

The productivity of agricultural systems is maintained or increased with technology, diesel, nutrients, pesticides, water, …

Photo: Lynn Betts, NRCS

Benefits we would like to derive from soils

• Produce food, feed, fiber, biofuel feedstocks, and

medicinal products

• Capture, filter, and store water
• Cycle and recycle nutrients
• Resistance and resilience to drought, temperature

extremes, fire & floods

• Protect plants from pathogens and stress
• Detoxify pollutants
• Store C and moderate release of gases (e.g., CO2, CH4,

N20)

• Stable – resist the erosive forces of wind and water

Soil biology is foundational to productive, sustainable cropping systems

• Biology drives production and ecosystem service

benefits 

• Soil organic carbon supports biology (both food

and habitat) 

• Crop, management and location determine

SOC levels

CO2 Plants Organic C inputs Active (days – years) Slow (decades) Passive (100s – 1000s years)

Carbon and soil organic matter

Of the organic carbon entering the soil:

• 2-5% active
• 3-10% slow
• 10-30% passive
• The rest becomes

CO2

Outline

• Text

Summary

Weil & Brady, The Nature and Properties of Soils, 15th edition

What is an in-field soil health assessment?

• An evaluation (typically qualitative) of selected soil

and/or plant characteristics (indicators) whereby relative soil function is inferred

Approaches to in-field SH assessment

Considerations for in-field soil health assessments

• Useful – provides valuable, accurate, meaningful information
• Usable – easily employed and interpreted by advisors and

farmers

• Works for your system(s)
• Minimizes subjective effects
• Quick
• No meters, chemicals, paper strips, etc. (essentially physical and

biological)

• Human sensory-driven
• Representative but reasonable sampling
• Encourages a conversation between the advisor and the grower
• Provides invaluable information for implementing soil test

recommendations

Helpful steps in soil health assessment

• Soil maps
• Info on inherent soil

properties

• Potential productivity
• Some soil health

information

• Producer conversation
• Current concerns
• Field & management

history and observations

• Field visit
• In-field soil health

assessment

Potential conversation questions

• What are the short- and long-term system management goals and
• bjectives?
• Are cover crops grown during typical fallow periods or between

perennial crop rows?

• If yes, for how many years has the field been continually cover cropped?
• How are the cover crops planted and terminated?
• What are types and frequency of ground disturbing operations?
• What is the crop rotation?
• What is the typical nutrient management program? What about other

amendments such as lime or gypsum?

• Are organic amendments such as manures or compost used? If so, how

frequently and what amount?

• Is soil water management a concern (i.e. field too wet or too dry at

planting)?

• Does water pond or run off during or immediately after rainfall events?

In-field indicators to assess soil function

Soil Cover Compaction Surface Crusting Biological Activity Residue Breakdown Aggregate Stability

SURFACE SUB-SURFACE

Other indicators that may be useful

• Water infiltration rate
• Respiration
• Roots & pores
• pH
• EC
• Soil smell
• Soil color
• Soil temperature
• Salt accumulation

Soil health field assessment – signs at the surface

Residue Breakdown Soil Cover

Biological shredding, fragmenting, cycling

• r incorporating of previous crop residue.

Rating Criteria Acceptable Unacceptable Residue pieces are small, mixed in surface or minimal crop residue remaining from >1 cropping seasons Large residue pieces after planting; can be handled without crumbling; or residue from 2 or more cropping seasons

An example of an assessment field sheet

Managing agricultural lands to improve soil health – copying a page from natural systems

• Minimize disturbance
• Keep the soil covered
• Increase system biodiversity
• Maintain roots in the soil

Challenges to changing management

• Costs associated with changing the system –

equipment, seed, time, etc.

• Peer pressure
• The unknown
• Pest population changes
• Covers use water
• Management and operations become more

complicated – learning curve

• Rented land
• Markets and buyer expectations
• Transition time to new “normal”

What is the cost of status quo?

Front page, USA Today May 22, 2018

Benefits from changing management: a farmer example

Rulon Enterprises, 6300 acres, corn and soybean, Arcadia, IN

• Can increase SOM 0.1%/yr, thereby increasing corn yield

goal by 2.7 bu/ac

• Using 20 lbs less P2O5, 30 lbs less K2O, 35 lbs less N than

conventional practices

• In 2017, planted 5200 acres to covers at a total cost of

$22.70/ac, net return of $57.76/ac, 254% ROI

• Short-term benefits of almost $42/acre
• Drought of 2012-13, county average corn ↓ 60 bu/ac,

Rulons ↓ 10 bu (long-term benefit)

• Essentially eliminated soil erosion (long-term benefit)

The Furrow, Summer 2018, Cash in on covers

THANK YOU!

Dir Direct comments an and questions to:

• :

den ennis is.chessman@ky.usd sda.gov 202 202-527 527-4000 4000

This information is provided as a public service and constitutes no endorsement by the United States Department of Agriculture or the Natural Resources Conservation Service of any service, supply, or equipment listed.

Cover Crops and Nitrogen Management Impact on Water Quality

Shalamar Armstrong Soil Conservation and Management Assistant Professor of Agronomy Purdue University Department of Agronomy

National News: The Gulf of Mexico's Dead Zone Is The Biggest Ever Seen

• Text

This week, NOAA announced that this year's dead zone is the biggest one ever measured. It covers 8,776 square miles — an area the size of New Jersey. And it's adding fuel to a debate

• ver whether state and federal governments are doing

enough to cut pollution that comes from farms. Farmers use those nutrients on fields as fertilizer. Rain washes them into nearby streams and rivers. And when they reach the Gulf of Mexico, those nutrients unleash blooms of algae, which then die and decompose. That is what uses up the oxygen in a thick layer of water at the bottom of the Gulf, in a band that follows the coastline. Scavia, however, recently published a blog post calling these voluntary measures inadequate.

Re Re-emergence of f Cover Crops

Cover crops influence on N availability and fate within common corn N management systems

N Conservation

• Soil inorganic N from

OM

• Residual N
• Applied N, if a

portion of N is applied in the Fall (DAP or Manure)

N Release

• Physiology
• Species:

Legume, grass, cereal

• C:N ratio

Inorganic N sources that cover crops interact with: Cover crop residue N release depends on:

N Uptake

Corn and Soybean N and Yield

Effect of f Cover Crops and Nit itrogen Application Tim iming on Nit itrogen Lo Loading Th Through Subsurface Drainage

Shalamar Armstrong1, Catherine O’Reilly2, Richard Roth3, Mike Ruffatti3,Travis Deppe3and Corey Lacey4

1 Assistant Professor, Purdue University Department of Agronomy, 2Associate Profess of Hydrogeology

Department of Geography-Geology, Illinois State University

3M.S. Candidate In Agriculture Sciences , Illinois State University Department of Agriculture, 4Graduate Research Assistant, Purdue University Department of

Agronomy

1.Change N application timing from fall to spring 2.Change N application timing from fall to spring + cover crop 3.Addition of cover crops to fall applied N

• ---Strip-till application of N into a living cover crop

Nutrient Loss Reduction Strategies Evaluated

Treatments

*Fall Anhydrous Ammonia was strip tilled into a living stand of Cereal Rye and Radish Mix

Total N rate for all plots: 224 kg ha-1

• 1. Control-No Fertilizer and No Cover crop
• 2. Spring Split Application of Nitrogen (20% Fall -DAP and 80% Anhydrous Ammonium)
• 3. Spring Split Application of Nitrogen (20% Fall-DAP and 80% Anhydrous Ammonium)

+ Cover Crops

• 4. Fall Split Application of Nitrogen (70% Fall-DAP and Anhydrous Ammonium and

30% sidedress- Anhydrous Ammonium)

• 5. Fall Split Application of Nitrogen (70% Fall-DAP and Anhydrous Ammonium and

30% sidedress- Anhydrous Ammonium) + Cover Crops

Research Design

A

• Rep. 1
• Rep. 2
• Rep. 3

Field History

• 10 years Strip-till before Corn and No-till before Soybeans
• Current Nitrogen Management : 60 % Fall N and 40% Spring N

15 Individually Tiled Fields: 1.6 Acres 72 rows

Tile Monitoring Station

Methodology – Cover Crop Planting

Cover Crop Mixture Daikon Radish (8%) Cereal Rye (92%) Seeding Rate: 84 kg ha-1 (74 lb/ A) Planting Date: Early to mid- Sept.

Cover Crop N Uptake

Fertilizer application timing did not significantly effect cover crop N uptake. Average shoot N uptake was 66 kg ha-1 (59 lb/A) On average the cover crop interacted with 30% of the N fertilizer applied.

* *

Can Cover Crops Reduce N Loading in all N Management Systems?

Reduction in N loading

Cover Crops + Corn

Change N application from fall to spring

Change N application timing from fall to spring + CC

Fall N vs. Spring N + CC

Leave N application in the fall + CC

Fall N +CC vs. Spring N + CC

Cover Crop Impact on Water Quality

Precipitation Total = 63 inches Annual Average = 25 inchers N Loading Treatment Comparison Fall N 52 kg ha-1 year-1 (46 lb/A) Fall N + CC 30 kg ha-1 year-1 (27 lb/A) 42% Spring N 60 kg ha-1 year-1 (53 lb/A) Spring N + CC 30 kg ha-1 year-1 (27 lb/A) 50% N Loading Treands Fall N vs. Spring N = Equal Fall N vs. Spring N + CC = 42% Spring N vs. Fall N + CC = 50% Spring N + CC vs. Fall N + CC = Equal

2:1 ratio between cover crop biomass N and N prevented from leaving the tile.

Potential Cover Crop N Cycling (2 (2:1 Ratio)

Cover Crops interacts with inorganic N within the soil solution that is less susceptible to loss via tile drainage. Cover Crops interacts with inorganic N within the lower portions of the soil profile that is more susceptible to loss via tile drainage.

Environmental Economic Implications of the Study

Erosion Rdeuction… Nitrogen Load Reduction 31% Cover Crop Biomass Mineralization and N Cycling 60% Conservation Scenario Range of Cover Crop Adoption Cost Recovery from Environmental Benefits

Cash crop yield differences considered 26-86% Assuming cash crop yield is equal 66-102%

Roth et. al., 2018 A cost analysis approach to valuing cover crop environmental and nitrogen cycling benefits: A central Illinois on farm case study, Agricultural Systems.

Cover Crop Performance on a Watershed Scale: Potential Impacts on Water Quality

Shalamar Armstrong1 , Catherine O’Reilly2 , Ben Bruening2, Corey Lacey4, Richard Roth4, Michael Ruffatti5, and Min Xu4

, 1Assistant Professor Agronomy, Agronomy Department, Purdue University, 2Associate Profess of Hydrogeology

Department of Geography-Geology, Illinois State University,, 4Graduate Student, Agronomy Department, Purdue University, and 5Support Agronomist, Department

• f Agriculture, Illinois State University

Plot scale analysis

• f Cover Crops
• Controlled

experiment

• Limited to no

farmer influence Watershed scale analysis

• f Cover Crops
• Reduced experimental

control

• Heavy farmer influence

Objective

Determine the impact of watershed scale mass cover crop adoption on water N loading.

Study Site:

• Lake Bloomington Watershed,

Towanda, IL

• Land use: 93% row crop agriculture,

>90% tile drained

• Dominant soils: poorly drained silty

clay loam and somewhat poorly drained silt loam that lies within a 0- 2% slope

• Number of farmers involved
• Treatment = 6 farmers
• Control = 4 farmers

Tile Water Sampling Locations

Control No-Cover Crop

262 ha Treatment Cover Crop 465 ha Lake Bloomington Watershed Towanda, IL

Cropping Systems and N Management Uncontrolled

33% 67%

Soybean (311 ha)

Corn ( 154 ha)

47% 53%

Fall N (165 ha) Spring N (144 ha)

36% 64%

Corn ( 93 ha)

Soybean (169 ha)

100%

Fall N (169 ha)

Treatment Watershed (Even Year Soybean Dominant) Control Watershed (Even Year Soybean Dominant)

35% of watershed land area 65% of watershed land area

Cover Crop Selection Uncontrolled

Note: Farmers used their knowledge of cover crops to drive their cover crop selection.

Cereal Rye/Radish before soybean Radish/Oats or Annual Rye/Radish before corn

Cover Crop Biomass and N Uptake (Fall 2015 and Spring 2016)

Above ground biomass was collected on 8 ha grids across the watershed and analyzed for %N.

26 lb/A 44 lb/A

Cover Crop Biomass and N Uptake (Fall 2016 and Spring 2017)

26 lb/A 22 lb/A 47 lb/A

Cereal Rye N uptake and Spring Soil IN Concentrations

P<0.0001

Spring 2016

Cover Crop Im Impacts on Water Quality

cover crop cover crop

Summary

Plot Scale

• On average, cover crops interacted with 30% of the N fertilizer applied.
• 2:1 ratio between cover crop shoot biomass N and N prevented from

leaving the tile.

• Cover crops reduced N loading via tile drainage by 42-50%, despite N

application timing

• Cover crop benefits of N cycling and N scavenging has the potential to off-

set a large percentage of the cover crop adoption cost. Watershed Scale

• Mass cover crop adoption on a watershed scale is possible.
• There was a signal of cover crop impacts on water quality.

Thank You!