Managing What You Can't See
- 1. Pasture Ecology -Managing Things That We Cannot See. Ed Rayburn Extension Specialist West Virginia University erayburn@wvu.edu
- 2. Pasture-Based Livestock Producers •In business harvesting solar energy. • Converting solar energy into food and fiber products for people. • Manage – plants to optimize harvest of solar energy, – animals to transfer that energy into livestock products, – cycling of mineral nutrients in the landscape – to make business socially, economically, and environmentally sustainable. • Are pasture ecosystem managers.
- 3. Energy Flow andNutrient Cycles
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- 5. Soil Organic Matter • Plant residues (dead plant material, course OM) • Active organic matter (rapid decomposition) • Slow organic matter (slow decomposition) • Passive organic matter (stable OM)
- 6. Citizens of theSoil Community • Plant roots and root nodules • Earthworms • Slugs and snails • Nematodes • Woodlice • Spiders and Mites • Centipedes and Millipedes • Spring tails • Beetles • Ants and Termites • Bacteria and Actinomycetes • Protozoa • Fungus
- 7. Soil Citizens ProvideCommunity Services • Nitrogen fixation • Nutrient cycling – shredders – decomposers – predators • Soil structure and aeration – water infiltration, holding capacity • Soil moisture affects microbial activity • Each has an optimum environment • Redundancy of functional species with different optima • Each has a niches • All participate in the soil food web
- 10. Photos From NRCS SoilBiology Web Site http://soils.usda.gov/sqi/concepts/ soil_biology/biology.html
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- 15. Arthropods (Insects andRelatives)
- 17. Dung Beetles (3niches) Dung Beetles of Central and Eastern North Carolina Cattle Pastures http://www.cals.ncsu.edu/entomology/guidetoncdungbeetles.pdf
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- 19. Slugs and Snails •Primary consumers • Shredders • Predators http://www.backyardnature.net/snail_sl.htm
- 20. Bacteria • Decomposers – immobilize nutrients in cells – make energy and nutrients available • Mutualists partner with plants – nitrogen-fixing bacteria • Pathogens • Chemoautotrophs – obtains energy from nitrogen, sulfur, iron or hydrogen not carbon compounds
- 21. Bacteria Services • Nutrient cycling – decomposition – hold nutrients • Disease suppression – compete with disease-causing organisms below and above ground • Water movement – substances bind soil particles into stable aggregates – water infiltration – water-holding capacity • Symbiotic bacteria with legumes – convert nitrogen from air to form plant can use • Nitrifying bacteria – change ammonium (NH4+) to nitrite (NO2-) then to nitrate (NO3-) • Denitrifying bacteria – convert nitrate to nitrogen (N2) or nitrous oxide (N2O) gas • Actinomycetes – decompose hard-to-decompose compounds, chitin and cellulose
- 22. Protozoa Help WithNutrient Cycling By Feeding on Bacteria
- 23. Protozoa Come inThree Forms, Amoeba, Flagellates, Ciliates
- 24. Free-Living Nematodes (4-types) •Bacterial-feeders consume bacteria. • Fungal-feeders puncture cell wall of fungi and suck out the internal contents. • Predatory eat other nematodes and protozoa. • Omnivores eat a variety of organisms or may have a different diet at each life stage. • (Root-feeding nematodes are plant parasites, and are not free-living in the soil)
- 25. Nematodes • Fungal-feeding • Bacterial-feeding
- 26. Fungi • DecomposeOM • Glomalin secretion develops soil structure • Extract nutrients • Hold nutrients
- 27. Fungi Help PlantsExtract Nutrients From Soil
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- 30. Basic Nutrient Cycling •Plant, bacteria and fungus – extract N from air or soil – extract macro and micro minerals from soil • Plant consumed by herbivore or dies • Herbivores deposit manure and urine • Shredders break large material into small bits • Bacteria consume rapidly degraded CHOs (sugars etc.) • Bacteria consume less degradable CHOs (fiber) • Fungi and actinomycetes consume even less degradable CHOs (fiber and lignin) • Macro and micro minerals released for plants • Organic forms of P and micro minerals more available to plants
- 33. Community Interactions • Legume,bacteria • Legume, bacteria, and grass • Legume, bacteria, fungus, and grass
- 34. N Transfer FromLegume (Clover & Bacteria) to Grass In a New Seeding. 25 20 Ryegrass w/ Ryegrass CP% 15 ladino clover Ryegrass w/o ladino clover 10 5 0 1-Feb 2-Apr 1-Jun 31-Jul 29-Sep 28-Nov 27-Jan
- 35. Transfers Between Legumes,Grasses, and Soil By Way of Mycorrhizae.
- 36. Community Interactions • Bacteriaand nematodes • Bacteria, mites, and nematodes
- 37. Interactions • Nematodes eat bacteria • Mites eat nematode • Nematodes eat fungus • Fungi eat nematodes
- 38. Healthy Soil EcologyBalance of • Food supply (organic matter with adequate macro- and micro mineral nutrients) • Physical environment above and below ground (cover and habitat at all scales) • Healthy consumers, omnivores, predators, and predators of predators (diversity) • Chemical environment (soil oxygen, pH, fertility) • Thermal and moisture environment
- 39. Management Needed toHelp the System (a) • Soil pH 6.0-7.0 depending on the legume • Adequate not excessive soil P and K • Inoculate legume seed with proper bacteria • Manage nutrients on the farm – (recycle manure, urine, and organic residues) • Proper grazing management – timing and intensity suitable for the forage mixture • Proper fall grazing – develop tillers in grasses and stolons of white clovers – reduce adult clover root curculio activity
- 40. Management Needed toHelp the System (b) • Rest pastures to get cover for night crawlers • Legumes for livestock and earthworms – they prefer legumes over grasses • Fly control friendly to dung beetles • Weed control friendly to legumes and soil micro organisms • Co-graze livestock – convert “weeds” to animal feed and manure
- 41. Take Home • Aboveground we manage plants with animals to capture solar energy, convert it into marketable livestock products, cycle nutrients so that our pasture system can be sustainable. • This management influences soil organic matter to feed macro- and microorganisms in the soil. • This affects the soil’s physical condition, availability of macro- and micronutrients and soil moisture to plants. • Understanding how management affects the soil community assists us in our management of the entire pasture ecosystem.
- 42. NRCS Soil Biology Web Site http://soils.usda.gov/sqi/concepts/ soil_biology/biology.html
- 43. Dung Beetles Dung Beetlesof Central and Eastern North Carolina Cattle Pastures http://www.cals.ncsu.edu/entomology/guidetoncdungbeetles.pdf
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