Measuring Health - Assessment Tools

Jeff Hemenway NRCS – Specialist Soil Health Indicators

• Chemical Physical • Chemical Physical • Biological

Biological What are we talking about? • Nutrient Deficiency/loss • Loss of • Loss of Biological diversity • Soil Compaction • • Soil Salinitization • Sodification • Others (etc.)

Chemical Soil Health Indicators

• Nutrient Supply (N, P, K) micros– (Conv. Lab Analysis) • Potentially Mineralizable Nitrogen – (Haney)? • Soil pH • CEC • Salinity and Sodicity – EC- Sat. Paste vs 1:1 – SAR 4 Physical Soil Health Indicators • (granular, subangular, platy) • Soil Pores/Macropores • Aggregate Stability (Wet, Jornada) • Bulk Density/Compaction • (single ring) • Surface residue/litter • Surface Crusting • Available Water Holding Capacity

5 Biological Soil Health Indicators

– Microbial Biomass (PLFA) – Soil Respiration (Solvita) – Potentially Mineralizable Nitrogen – (Haney)? – Plant Roots (number/mass) – Other Indicators (, ) – Others

Soil Degradation Spiral

Poor Land Management Aggregation Degradation

Compaction Soil Biology & crusting Water & Wind Erosion Plant Growth

Yield

Reduced Soil Productivity SOIL C LOSS/ORGANIC MATTER LOSS

8000 7500 Conventional Reduced 7000 Tillage Tillage 6500 6000 61% of 1907 5500 5000 53% of 1907

Soil C (g m-2) (g C Soil 4500 4000 3500 3000

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 Year

Management (HIGH) Changes CRP Grass ? Farmer No Tillage ? Cover Crops ?

Decisions

(LOW) Intensive Tillage Stover? Removal ?

Soil Carbon Content Native Sustainable Prairie Row Crop Agriculture Production? -100 -80 -60 -40 -20 0 20 40 Years Before Present | Years After

South Dakota Acres Under No-Till Farming on All Planted Cropland Tillage is Destructive to What things change when you stop tilling the soil? • Soil pores remain continuous • Soil aggregates form and are not destroyed • Soil Food Web increases and diversifies • Weed seeds are not planted • Water is captured (infiltration) and stored (AWC) • Bulk density increases slightly; then stabilizes • Soil fungi and increase • Microarthropods increase Dynamic Soil Properties -2008

• Study was initiated in 2008 to look at – Effect of management/invasive species on soils – Further define causes of transitions between states • What are the dynamic soil properties – Color/organic matter – Soil aggregate stability – Bulk density/porosity – Microflora and microfauna – Carbon:Nitrogen ratio – Infiltration Dynamic Soil Properties Study Sites

2009 2014 2009

2008 &2013 2012 &2013 2016

2008

2015 2012

2015 DSP Study sites Dynamic Soil Properties

Barnes – Loamy ecological site 2008 Study site Duel County, SD Dynamic Soil Properties study site

Similar to Rapid Carbon Assessment protocol Paired sites are located on same soil, but widely different management Study Site 1 – Bruce, Steve and Lance collect soil samples on the native state. The soil series is Barnes. Barnes soil Native / Invaded State Invaded State 88% Native grasses, 89% Introduced forbs & shrubs species (5 species) (19 species) 11% Native grasses 12% Introduced and forbs (6 species (3 species) species) (by weight) (by weight)

Infiltration

25 I n 20 c h 15 e s 10 / 5 h 5 r 0.55 0 Rotation Continuous Bulk Density

1.4

1.2

1

Bulk 0.8 Density Native (g/cm3) 0.6 Invaded 0.4

0.2

0 0-3" 3-6" Horizon Soil Aggregate Stability

6.0 5.5 5.0 4.5 4.0 3.5 Stability 3.0 Rating 2.5 Nat ive 2.0 Invaded 1.5 1.0 0.5 0.0 Surface 0-3" 3-8" 8-12" Horizon 120.0 109.2

100.0

80.0 1st Inch 60.0 2nd Inch 40.0 27.6

Elapsed Time (min.) 21.0 20.0 1.2 0.0 Nat ive Invaded

Infiltration – There were dramatic differences between the two states in infiltration rates. On the invaded grass state, the second inch of water took more than 5 times longer to enter the soil. After the initial wetting, the infiltration rate was approximately 2.17 inches/hour for the native state, and 0.55 inches/hour for the invaded. Carbon/Nitrogen Ratio

• No appreciable difference • Organic matter – Total amount not greatly different – Distribution significantly different – better distribution of organic matter in the soil profile under rotationally grazed

• An indicator of arbuscular mycorrhizal fungi activity. • Native grass site had 20% more glomalin in the soil profile compared to the invaded grass site. – Is this enough of a difference to be considered a trigger for the effect on infiltration? – Would the change in glomalin be sensitive enough to use as an early warning sign?

Dynamic Soil Properties - Sampling Protocol Notes: Proposal Rapid carbon protocol plus Soil Sampling Standard Cluster sampling – i.e. central pedon plus four cardinal satellites - 30 meters from center 5 cm - surface subsample BD sampling all horizons Complete morphological soils description – (i.e. – 232) Single ring infiltration – central pedon plus all satellites Total carbon Inorganic carbon -Active carbon, POM, permanganate test?, humic acids? - Note: May need to do carbon on all horizons ; not just A horizons. Ec pH Soil Aggregate stability – A horizon(s) Central pedon – sampled for soils characterization

Plant Sampling NRI procedure – 5 plot total harvest Point Intercept procedure Duff layer collection – measure thickness?

•2012 Study Site Mellette County, SD

Dynamic Soil Properties- (i.e. Soil Change with Management) 2012 Study Site Mellette County, SD Mellette County Kube soil

Rotational Grazing Hayland Mellette County Kube soil

Rotational Grazing Hayland Mellette County Kube soil

Rotational Grazing Hayland Mellette County Kube soil

Rotational Grazing Hayland Mellette County Kube soil

Rotational Grazing Hayland Kube Soil – Native Kube Soil – Cropland si Range site Infiltration Rates Infiltration Rates SD001-1 3hr. 57 min. SD002-1 30 sec. SD001-2 34 min. SD002-2 2 min.25 sec. SD001-3 37 min. SD002-3 34 sec. SD001-4 52 min. SD002-4 50 sec. SD001-5 2 hr. 29 min. SD002-5 6 min. 47 sec. Average - 1hr. 41 min. Average - 2 min. 13 sec.

• 2014 Study Site Walworth County, SD

Cropland/New range seeding

Native Range Cropland/New range seeding Grass/Alfalfa prior to 2011, No-till Oats/peas 2012, Sorghum/sudan in 2013, Range seeding in 2014: Big Bluestem, Side Oats grama, Green Needlegrass. Indiangrass, Switchgrass, Little Bluestem, forbs Native Range Dominant and subdominant species (in order of dominance) are: Smooth bromegrass, Kentucky bluegrass, western wheatgrass, needleandthread, crested wheatgrass, and western snowberry. Mobridge Mobridge Native Rangeland Cropland – Range Seeding

Infiltration Rate -2nd Inch Infiltration Rate -2nd Inch

005A 17 min. 6 seconds 006A 48 minutes 005B 22 min. 30 seconds 006B 3 hrs 35 minutes 005C 1 min. 30 seconds 006C 4 hrs 50 minutes 005D 6 min. 18 seconds 006D 16 minutes 005E 14 min. 30 seconds 006E 26 minutes

Ave. 12 min. 23 seconds Ave. 1 hr 59 minutes

What we “know” so far • Management actions can be taken to degrade or improve soil health – more emphasis needs to be placed on this. • Management of cropland and grassland has a potentially large effect on infiltration/runoff. • We need to sample-N,P,K micros S, Zn,Cl • A number of soil parameters are showing more promise – C, OM, Structure, WAS, BD, EC, Infiltration.

Soil Health in South Dakota Predicting Infiltration Rates

Predicting Infiltration rates for Grazing lands and Cropland • Based on plant community and management for both systems • Grazing land • ESD Plant community and grazing management • Cropland • Crop rotation and tillage system

RAINFALL INFILTRATION KIT

Grazing land ESD Plant Community – Management Scale

Both the plant community and the type of management are rated on a five- tier scale.

Plant community (comparisons are to the respective ecological site description):

1 – Native plant community 2 – Plant community dominated by native plants 3 – Non-native cool-season grasses and/or short warm-season grasses have increased to the point of being co-dominant with native species which are normally considered dominant in the reference plant community. 4 – Non-native cool-season grasses and/or short warm-season have increased to the point of being dominant. 5 – Non-native cool-season grasses and/or short warm-season grasses have increased to the point of being completely dominant. If present, native species are difficult to find. Grazing land ESD Management: 1 – Prescribed grazing is applied according to the Prescribed Grazing Conservation Practice Standard (528). 2 – Most aspects of the Prescribed Grazing Conservation Practice Standard (528) are applied, but not consistently. 3 – Typically this includes grazing at moderate stocking rates, but grazing periods cover most of a season (seasonal) or nearly for the entire season (season-long 4 – This typically includes moderate to heavy stocking rates that are applied season-long. Livestock often occupy the area for most of the growing season. 5 – This typically includes very heavy stocking rates for extended periods, often for the entire growing/grazing season.

To determine the plant community/management scale rating, rate each using the scales above, then multiply the two numbers together. The overall rating will range from 1 to 25.

34 locations, 7 MLRAs, 8 ecological sites

Cropland Crop Rotation and Plant Diversity Management Scale

Both the rotation and the tillage system are rated on a five-tier scale. Rotational System 1– Diverse cropping system that includes all four crop types. Perennials as well as cover crops are part of the system. Contains at least two thirds high residue crops – or grazing is part of the management system. 2 – Cropping system that includes all four crop types incorporated into the crop sequence. Contains at least two thirds high residue crops. 3 – Cropping system that includes at least 3 crop types in the cropping sequence. Contains 50-60% high residue crops with cover crops are part of the rotational system. 4 – Cropping system includes 2 crop types with 50% high residue crops or high residue mono-cropping systems. 5 – Mono-cropping system with a low residue crop Cropland Tillage System: 1) No-till/strip-till - The soil is left undisturbed from harvest to planting except for strips up to 1/3 of the row width (strips may involve only residue disturbance or may include soil disturbance). 2) Ridge-till - The soil is left undisturbed from harvest to planting except for strips up to 1/3 of the row width. Planting is completed on the ridge and usually involves the removal of the top of the ridge. Planting is completed with sweeps, disk openers, coulters, or row cleaners. Residue is left on the surface between ridges. 3) -till – Full-width tillage that involves one or more tillage trips, disturbs the entire soil surface and is done prior to and/or during planting. Tillage tools such as chisels, field cultivators, disks, sweeps or blades are used. 4) Reduced-till (15-30% residue) - Full-width tillage that involves one or more tillage trips, disturbs the entire soil surface and is performed prior to and/or during planting. There is 15-30 percent residue cover after planting or 500 to 1,000 pounds per acre of small grain residue equivalent throughout the critical wind erosion period. 5) Conventional-till or intensive-till - Full-width tillage that involves one or more tillage trips and disturbs the entire soil surface and is performed prior to and/or during planting. There is less than 15 percent residue cover after planting, or less than 500 pounds per acre of small grain residue equivalent throughout the critical wind erosion period. Generally involves plowing or intensive (numerous) tillage trips.

Actual Values 2nd Inch

Actual Values 1st Inch