Managing Grazing to Regenerate Soil Health & Farm Livelihoods

Transcription

1 Improving Life through Science and Technology Managing Grazing to Regenerate Soil Health & Farm Livelihoods Richard Teague, Texas A&M AgriLife Research OACD Conference Oklahoma City 27 Feb 2018

2 Our Research Team Goal Use a systems, multi-discipline framework to find: What is the best grazing management for regenerating: Soil health and function, Delivery of ecosystem goods and services, Farmer livelihoods and social resilience?

3 Research Framework and Hypothesis: Carbon rich soil is healthy soil and beneficial for the entire ecosystem Healthy Ecosystems function by drawing down CO 2 into the soil, resulting in: Improved water infiltration and retention; Improved soil nutrient status, access and retention; Increased diversity of fungi, microbes, plants, insects, wildlife; Reduced soil erosion and reduced NET GHG emissions; and Contributing to both improved livestock and farmer well-being.

4 Biggest limiting factor in grazing land Water in the Soil H 2 O H 2 O

5 90% of Soil function is mediated by microbes Microbes depend on plants So how we manage plants is critical Ingham 2000; Jones 2016; Lehman et al. 2016

6 The Four Ecosystem Processes 1. Energy flow - Maximize the flow of solar energy through plants and soil. 2. Hydrological function - 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 stability and productivity Terrestrial Ecology 101

7 Landscape impact of continuous grazing 1. 39% area used 2. 41% GPS points on 9% area 3. SR: 21 ac/cow 4. Effective SR: 9 ac/cow Norton 1998; Norton et al. 2013; Jakoby et al. 2014

8 Light continuous grazing patch selection no recovery Heavy continuous grazing

9 Continuous grazing H 2 O CO 2 Regenerative AMP Grazing H 2 O CO 2

10 Regenerative AMP grazing Manager can control: How much is grazed The period of grazing, and The length and time of recovery Water points added as needed Animals: Graze more of the whole landscape, one paddock at a time Select a wider variety of plant species Norton et al. 2013; Jakoby et al. 2014; Teague et al. 2015

11 To be sustainable grazing must AVOID: Overstocking i.e. Not having enough forage for the livestock and maintaining ecosystem function Overgrazing i.e. Grazing periods too long and recovery periods too short AMP grazing protocols facilitate adapting management as weather and other conditions change to avoid problems and attain desired best outcomes.

12 Continuous Grazing Ranch road Water point

13 Application of AMP Grazing Ranch road Existing fence Electric fence Water point Norton et al. 2013; Jakoby et al. 2014; Teague et al. 2015

14 Regenerative Grazing Noble Foundation, Coffey Ranch Poor condition range 18 paddocks + 1 water point Managed to improve plant species

15 Restoration Regenerative using multi-paddock Grazing grazing Noble Foundation, Coffey Ranch Charles Griffith, Hugh Aljoe, Russell Stevens Animal Unit Days

16 Managing AMP Grazing for Best Results Aim to improve ecological function to increase profits Flexible stocking to match forage availability and animal numbers Spread grazing over whole ranch, by grazing one paddock at a time Defoliate moderately in growing season Use short grazing periods Adequate recovery before regrazing Adjust as forage growth rates change Norton et al. 2013; Jakoby et al. 2014; Teague et al. 2013; 2015

17 Reasons for failing to get positive results Too many animals before soil and plants had improved Not developing suitable stock water system Inadequate planning Fixed rather than adaptive management as conditions change Defoliating too heavily in growing season Long grazing periods Inadequate recovery before regrazing Expecting improvements where conditions are very limiting Teague et al. 2013; Teague & Barnes 2017

18 Previous research Generally: Had no goal to achieve best results with each treatment Ignored substantial influence of spatial scale on animal impact Used small-plot reductionist experimental design Measured production but NOT ecological indicators Elevated animal numbers on rotational grazing treatments before soil and plants had improved Has had inadequate recovery periods Has not proactively managed as conditions change to achieve desirable goals Has been very short-term Teague et al. 2013; Teague & Barnes 2017

19 What we need to know: Understanding causal mechanisms is critical to knowing how to manage to regenerate from a degraded situation. What are the mechanisms causing degradation? What management reverses degradation? How good is AMP management as a restoration and management tool? Where does it work and not work? How does it need to be managed to make it work as well as it can?

20 Importance of Microbes and Fungi Improve soil structure Improve nutrient access for plants Extend root volume and depth Produce exudates to enhance soil C Increase water and nutrient retention Plant growth highest with high fungi Fend off pests and pathogens Fungal mycelia Ingham et al. 1985; Lehman et al. 2016; Montgomery 2017 Bacterial rhizobia

21 Earthworms in the ecosystem Epigeic Endogeic Enecic Edwards 2005; Blouin et al. 2013

22 Dung beetles in the Ecosystem Tunnelers Dwellers Rollers Herrick & Lal 1995; Richardson et al. 2000

23 High density Regenerative AMP grazing 200 cows drop 25 tons of dung a week Increase infiltration ~ 130% Reduce flies

24 Hypothesized Causal Mechanisms: Energy Flow Water Cycle Mineral Cycle Soil faunal + plant Diversity AMP grazing Continuous grazing

25 AMP Grazing Light continuous grazing No-grazing Energy Flow Water Cycle Mineral Cycle Soil & plant Diversity

26 Initial Texas Grazing Research AMP grazing gave 3 tc/ha/year more than usual heavy continuous grazing Decreased bare ground Bolstered soil fertility Enriched soil microbial composition Improved soil water holding capacity Improved plant species composition Enhanced plant productivity Increased livestock production Teague et al. 2011; Wang et al 2015

27 Published research AMP had higher C gain/year than continuous grazing neighbors Measured to 1 m 3 tc/ha/yr over 15 years Wang et al. 2015

28 Paired AMP, HCG, and LCG Soil Catena Sampling Catenal position

29 Published & Reconnaissance Sampling AMP had higher C gain/year than continuous grazing neighbors Apfelbaum et al tc/ha/yr over 20 years Apfelbaum et al 2016 < 0.5 tc/ha/yr over 20 years 3 tc/ha/yr over 15 years Wang et al tc/ha/yr over 5 years Apfelbaum et al 2015; Williams 2017

30 AMP Grazing After 3 years Continuous grazing Soil OM < 1% Soil OM up to 10% Infiltration < 1 / hour Infiltration up to 10 / hour

31 Need to measure C flux into and out of soil 13 CO 2 Isotope Sampling 3.0 tc/ha/yr

32 Soil Carbon changes with human management Carbon level prior to Europeans Conventional grazing begins Regenerative grazing research needs to be conducted here sampling at least to 1 m, preferably 2 m Most research conducted here with sampling at 15 to 30 cm Regenerative grazing begins

33 Building Soil Carbon Using AMP Grazing 6 5 Measured to 200 mm Soil Organic Matter (%) MS AL GA MO NY ND 0 Year 1 Year 2 Year 3 Year 4 Year 5 Years from start of AMP grazing For 200 mm gives a mean increase of 8.6 tc ha -1 year -1 Williams et al. 2017

34 AMP Grazing on Converted Crop Fields Georgia 1,000 mm rainfall Machmuller et al. 2015

35 SOC Switching from Cropping to AMP 8 tc ha yr -1 over 6 years Measured to 30 cm Tons C ha 1

36 Continuous grazing AMP Grazing Over 10 years Soil OM < 1% Soil OM up to 10% Infiltration < 25 mm/hr Infiltration > 200 mm/hr

37 Building Microbial Biomass (ng/g of Soil) Year 1 Year LA IL IA NE MO Williams et al

38 Infiltration on HCG vs. AMP grazing Northern Great Plains 70 Infiltration (cm hour -1 ) HCG AMP 10 0 Towers Hoven Holtman Cross Dennis Brown Apfelbaum et al 2016

39 Clear Creek watershed, North Texas Danglemayr Pittman Legend Mitchell Stream Gage Clear Creek Ranch CCW Land use Agriculture Water Residential Bare field Forest Rangeland Leo Park et al Kilometers

40 Clear Creek watershed, North Texas 0.8 Surface runoff Groundwater flow Fraction in total flow Park et al HC LC AMP EX Grazing management scenario

41 Clear Creek Nitrogen load 300 Total nitrogen load (ton yr -1 ) Park et al Baseline HC LC AMP EX Grazing management scenario

42 Clear Creek - Phosphorus load 300 (c) Total nitrogen load (ton yr - 1 ) Park et al Baseline HC LC AMP EX Grazing management scenario

43 Using Cover Crops and Grazing to Boost Soil Health and Profits in Cropping Systems High density grazing Multi Species Cover Crops

44 Cover crop with 25 species Gabe Brown, N Dakota AMP grazed Cover crop

45 Moving to the next paddock Is this wasted forage?

46 Grazing and Cover Crops Boost SOC North Dakota 400 mm rainfall Livestock Integration Soil C (%) No Till Crop Diversity Cover Crops Multi-Species Cover Crops Delgado et al 2011; Rodale 2014; Jones, 2014; Fuhrer 2015

47 Soil Improvements with Regenerative Management Colin Seis, New South Wales, Australia 2016 Carbon 200% Silicon 116% Water holding +200% Nitrogen 103% Calcium 234% Phosphorous 102% Magnesium 110% Potassium 198% Zinc 250% Sulfur 92% Copper 185% Iron 87% Boron 150%

48 Life Cycle Analysis North Texas Net C Emissions on grazing only Cow-calf Operations HC grazing HC to LC HC to AMP Wang et al. 2015

49 Emissions and Carbon Sinks: Michigan Grassfed Pasture grazing Cow-calf Operations LCA Impact of Change in Management kgco2e ha 1 yr Low Input AMP Irrigation + AMP Emissions Emissions Sequestration Sequestration 1500 Rowntree et al. 2016

50 Net emissions: Feedlot vs. AMP finishing: 10 No Soil C Flux 9.62 LCA Impact of Change in Management With Soil C Flux kgco2e kg CW Emissions Sequestration 4 AMP grazing Feedlot Paige Rowntree & Rowntree et al. et 2016 al.

51 Working with leading farmers Addresses questions at commercial scale Integrates component science into whole-system responses Identifies emergent properties Includes the human element essential for achieving economic and environmental goals Incorporates management to adaptively achieve desired goals Indicates how to manage adaptively Facilitates identifying unintended consequences Van der Ploeg et al 2006; Teague et al. 2016; 2017

52 What we have learnt from ranchers...1 It takes a minimum of 10 paddocks just to stop overgrazing Ranchers with 8 or fewer paddocks are not rotationally grazing, but rotationally overgrazing To support decent animal performance takes paddocks The most rapid range improvement takes 30 or more paddocks The biggest decrease in workload and greatest improvement has been with > 50 paddocks Walt Davis, Dave Pratt, Ranch Management Consultants

53 What we have learnt from ranchers...2 The fastest, cheapest way to create more paddocks is combining herds 1 herd reduces workload a lot; checking 4 herds of 200 animals takes much longer than 1 herd of 800 Productivity per acre is improved without decreasing individual animal performance Carrying capacity and total productivity are greatly increased at low cost Long recovery periods are critical Do not move to the adjacent paddock but to the paddock that has recovered the most Walt Davis, Dave Pratt, Ranch Management Consultants

54 AMP Research Shows: Ecological function and profitability increase with increasing number of paddocks Short periods of grazing with adequate recovery gave the greatest profit and ecological function Adjusting grazing management with changing conditions increases ecological function and profitability Fixed management protocols reduced benefits Profitability decreases if recovery is too short or too long Stocking rates can be increased without damaging ecological function as number of paddocks is increased Martin et al. 2014; Jakoby et al. 2014; 2015; Teague et al

55 Regenerative AMP grazing can: Build soil Carbon levels and soil microbial function Enhance water infiltration and retention Build soil fertility Increase food nutrient density Control erosion more effectively Enhance watershed hydrological function Enhances wildlife and biodiversity Increase soils as NET greenhouse gas sink Improve livestock production and economic returns while improving the resource base Norton et al. 2013; Jakoby et al. 2014; Teague et al. 2015

56 Managing AMP Grazing for Best Results Aim to improve ecological function to increase profits Flexible stocking to match forage availability and animal numbers Spread grazing over whole ranch, by grazing one paddock at a time Defoliate moderately in growing season Use short grazing periods Adequate recovery before regrazing Adjust as forage growth rates change Use more than 1 class of livestock Norton et al. 2013; Jakoby et al. 2014; Teague et al. 2013; 2015

57 Thank you

58 AMP Field & Modelling Research Shows: Adaptive stocking is less sensitive to overstocking than constant stocking The advantages of AMP over continuous grazing are less important at low levels of stocking but become increasingly important as stock numbers increase, improving net economic returns (Jakoby et al. 2015) Short periods of grazing with long periods of recovery afforded by using a greater number of paddocks per herd allowed higher stocking rates (Barnes et al. 2011), This results in higher net returns, lower income variability, protection of the resource base, and facilitated resource restoration over a wide range of possible management scenarios Martin et al. 2014; Jakoby et al. 2014; 2015; Teague et al

59 Continuous grazing AMP Grazing Soil OM < 1% Soil OM up to 10% Infiltration < 1 / hour Infiltration up to 10 / hour