Soil Health, Forage & Grazing. Timm Gergeni Advisor: Dr. Derek Scasta

Transcription

1 Soil Health, Forage & Grazing Timm Gergeni Advisor: Dr. Derek Scasta

2 Practical Aspects of Soil Health Dr. Kristie Maczko Dr. John Tanaka

3 What is Soil Health? Soil health refers to a soil s capacity to function as a vital living ecosystem that sustains plants, animals and humans.

4 More Specifically To address/identify the Practical Aspects of Soil Health that may be useful to producers. Potential Indicators

5 How is Soil Health Measured? Physical Chemical Biological

6 Research Questions What does the literature tell us? Can Wyoming producers build/improve soils on grazing lands with proper grazing management? Can useful information be obtained at the ranch-scale?

7 What we know Grazing lands occupy ~40% of the earth s terrestrial surface Thus, resulting in the ability to store large amounts of C- how? Organic Matter = ~58% C Effects of grazers have resulted in positive, negative and neutral outcomes Environment and Soil texture

8 Organic Matter Water holding capacity Soil aeration Plant nutrient availability Soil temperature Food for soil microbes Aggregate stability

9

10 Research Outline Literature Review SAREC Sims Cattle Company

11 Literature Review/Global Review Grazing Key Word(s) Grazing Rotational Grazing Mob Grazing Ultra High Density Grazing Stocking Rate Grazing X Soil Key Word(s) Soil Health Soil Stability Soil Compaction Soil Organic Matter Soil Carbon Management Intensive Grazing Soil Nitrogen Body Condition Score Soil Bulk Density Animal Performance Soil Microbes Soil Quality

12 Results 3,600 titles/results including duplicates Relevant titles & abstracts reviewed 158 publications reviewed 2010 Average date of publication All continents 6 Previous global reviews/meta-analyses 1 study = soil + forage + animal Disproportionate amount of studies exploring cell, mob grazing and multi-paddock research stations

13 ~5% ~20% ~10% ~40% ~10% ~5% ~5%

14 Gaps and Concerns 6 global reviews found 40% of studies from highly degraded sites in Asia 1 study linking all 3 components (soil + forage+ animal performance) Cattle and sheep graze differently

15 SAREC Highly controlled Lingle, WY Ecological site RO67XY122WY Silt Loam- Coarse-silty, mixed, superactive, calcareous, mesic Ustic Torriorthents MAP inches MAT F June 2017-June 2019

16

17 Design Randomized complete block design 4 replications of each treatment = 12-1 acre paddocks All cattle will have access to water in each paddock All LC paddocks will be grazed simultaneously UHD paddocks will be rotationally grazed (1 rotation)

18 Treatments NG = Not grazed (control) LC = Light continuously grazed (2 heifers) UHD = Ultra high density grazing (>50,000 lbs./acre) 45 cows ~58,500 lbs./acre Grazing will occur until predetermined amount of forage removed (~50%) Animals removed until following year Sampling done prior to grazing and following last grazing event

19 Something like this

20 Potential Site

21

22 Sims Cattle Company McFadden, WY 3 herds ~300 animals each 140 pastures from <6 acres to >1200 acres Rest periods >1year Excellent records (1989) Animal days in pasture

23 Sims Cattle Company Ecological site R034XY362WY Shallow sandy loam MAP 9-14 inches MAT F ( frost-free) western wheatgrass, needleleaf sedge, sandberg bluegrass, hoods phlox, birdfoot sagebrush, gardners saltbush, and big sagebrush.

24

25 Pasture Records

26

27 * * *

28 Animal Days/Acre Small difference may be substantial For example: Herd > 300,000 lbs. 1 more animal day per acre over 30 yrs = 30 more days of animal 300,000 lbs. Or the ability for the pasture to produce 234,000 lbs more of forage. 26*300*30 = 234,000

29

30

31 104 Alcova 110 Anchutz

32 Criteria Upland, not irrigated, no tillage, no burn, records pastures sampled to 10cm 5-7 in Alcova (104) 5-7 in Anchutz (110) Relationship between animal days in pasture, soil health and forage 3 exclosures

33 Laboratory Analyses Plant available nutrients Haney Test PLFA Field Tests Soil Sampling Aggregate stability Infiltration Soil time of sampling Penetration resistance

34 Forage analyses Vegetation quadrat Composition (species) Biomass production Protein Fiber

35 Producer s Concerns Am I building Organic Matter? Soil sampling results in fertilizer recommendations- you don t fertilize nonirrigated rangelands. What use are soil tests to me? Adapt/Change?

36 Ask me next year Conclusions