Nematodes and Soil Quality George W. Bird, Professor Marisol Quintanilla Department of Entomology Michigan State University August 8, 2005 NEMATODES AND SOIL QUALITY August 8, 2005 Schedule 1:00 to 1:50 pm 2:00 to 2:15 pm 2:15 to 2:20 pm 2:30 to 2:45 pm 3:00 to 3:20 pm 3:20 to 3:50 pm 3:50 to 4:10 pm 4:10 to 4:40 pm 4:40 to 5:00 pm Soil Food Web Lecture (Professor Bird) Nematode Extraction Exercise (Marisol Quintanilla) Water Stable Soil Macro-aggregate Exercise (Professor Bird) Soil Respiration Demonstration (Professor Bird) Travel to Department of Entomology Collins Road Field Facility Nematode Population Dynamics Field Visit & Demo (Professor Bird) Travel to the Student Organic Farm Field The Biology of Compost Demonstration (Marisol Quintanilla) Return to Michigan State University Campus Structure + Process Patterns How Soil Works Nature of Soil Nematodes Soil Quality 1
1. What is Soil? Outer most layer of our planet Regenerative living system Ecosystem (Biotic, Abiotic, Boundaries) Place where energy and matter are transformed and transported. 2. What organisms colonize the planet Earth (Oceana)? Three Domains and 23 Kingdoms of Life (Science, Vol 275:1740) (all but three are microscopic) Domain No. 1 Domain No. 2 Domain No. 3 (6 Kingdoms) Arachaee (6 Kingdoms) Eukarya Animals Plants Fungi (8 other kingdoms) Viruses (chemical messengers) ssrna ssdna dsrna ssrna multiple components Prions (Protein fragments) 3. What organisms living in the soil? Plant Roots Earthworms Actinomycetes Nematodes Protozoa Fungi Arthropods 2
4. What is soil made of? Gaseous (Air) circa 25% Liquid (Water) circa 25% Solid (Mineral) circa 45% (Organic) <1% to circa 10% 5. What is the difference between the processes of mineralization and fixation? Ionic (Mineral) Forms NH + 4 NO 3 - MIneralization Fixation (assimilation) Organic Forms Proteins (Amino Acids) Nucleic Acids Microbial cell wall Nitrogen Transport and Transformation Bird, 2004 6. What are bacteria and what do they do in the soil? (Consumer/Decomposers) 5:1 (C:N ratio) Feed/Metabolize Transport and Transform Nutrients Immobile C and N Mineralize C and N Replicate Hybernate Die (consumed) E. coli survived the Columbia Space Shuttle Crash of February 1, 2003. 3
l Feeders 7. What are nematodes and what types exist in soil? Plant Feeders N.A. Cobb (1915) if all the matter in the universe except the nematodes was swept away, our world would still be dimly recognizable we would find mountaintops, valleys, rivers, lakes and oceans recognizable by a thin film of nematodes. Fungal Feeders Algal Feeders Omnivores Carnivores 8. What do nematodes do in soil? 10:1 (C:N ratio) Feed (Bacterivores) Release NH 4 + Mobilize C and N Reproduce Hybernate Die The nematode C. elegans survived the Columbia Space Shuttle Crash of February 1, 2003. Energy CO 2 9. What is the role of nematodes in nitrogen mineralization? Shoot System Rhizosphere NH 4 + NO 3 Nematode C:N 10:1 Root System Sugar Exudate C:N 5:1 H 2 O Nutrients Bird, 2002 4
10. How do bacterial feeding nematodes impact primary productivity? Ingham, R. et al. 1985. Ecological Monographs 55:199-140. Structure + Process Pattern 11. Where are nematodes found in soil? Bacterivores Surface litter 0 to 6 6 to 12 1,374 b 34 a 94 a 0.001 Herbivores Fungivores Omnivores Carnivores 29 a 15 a 17 a 31 a 82 b 24 a 0.499 0.004 22 b 18 b 4 a 0.008 11 a 11 a 4 a 0.485 Nematodes/100 cm 3 soil or litter. Bird, 2002 12. Where are flagellates, amoebae and ciliates found in soil? Flagellates Surface litter 0 to 6 6 to 12 139,799b 5,758 a 2,634 a 0.001 Amoebae Ciliates 39,380 b 9,321 a 1,515 a 0.001 2,334 b 266 a 112 a 0.007 Bird, 2002 5
13. Are there more flagellates in organic soil than in conventionally managed soil? Flagellates Organic Surface litter 258,344 T-test 0.002 Conventional 21,235 0 to 6 6,991 T-test 0.445 4,524 6 to 12 2,342 T-test 0.776 2,928 Bird, 2002 14. Does soil management impact nematode community structure? Structure + Process Pattern MSU Extension Bulletin E-2759 MSU Extension Bulletin E-2759 15. Do cover crops impact risks of ground water to chemical pollutants? 6
n Bacterivore Enrichment Index SQT C Non-stable but Nutrient Enriched SQT A Stable, Enriched and Regenerative (T 3 ) SQT B SQT D Stable, Non-stable and but Nutrient Nutrient Depleted Depleted (T 1 ) (T 2 ) Carnivore Algavore 0 Structural n Herbivore Fungivore Omnivore Soil quality types (A-D), nematode community structure stability and enrichment indices (T = time). Harvested Crop Biomass Crop Plant (Autotrophs, Primary Producers) Pathogenesis Senescence Pathogenesis Dead or Decaying Organic Matter (Detritus) Decomposition Decomposition Inorganic Nutrient Pool Fungi Inorganic Nutrient Pool Consumption l Feeding Nematodes, Amoebae, Flagellates and Ciliates Parasitism Fungal Feeding Nematodes Predation Predaceous Nematodes (Omnivores/Carnivores) Predation Nutrient Inputs (Compost, Mulch, Manure, Fertilizers) Role of soil fauna in nutrient cycling associated with crop production (modified from R.E. Ingham et al., 1985). Soil is a dynamic place where organisms interact and transform-transport matter and energy. This can be understood by asking questions about. Structure + Process Pattern 7