Biological Consideration of Soil Health Mario Tenuta www

Biological Consideration of Soil Health ? ? Mario Tenuta www. soilecology. ca @soilecol. UMan Atlantic Soils, Soil Conservation Council of Canada Moncton Nov 17, 2016

Soil Quality vs. Health? Soil Conditions to Predict Productivity Soil Quality “Capacity of a soil to function within ecosystem boundaries to sustain biological productivity, maintain environmental quality, and promote plant and animal health” (Doran & Parkin, 1994) Soil Health “The continued capacity of soil to function as a vital living system, within ecosystem and land-use boundaries, to sustain biological productivity, promote the quality of air and water environments, and maintain plant, animal and human health” (Doran & Safley, 1997) Soil Conditions to Predict How Soil Functions Good Functioning Does Not Imply Good Productivity

How Soil Organisms Improve Plant Health • • • Decomposition of organic matter Cycling of minerals and nutrients Reservoirs of minerals and nutrients Redistribution of minerals and nutrients Sequestration of carbon Degradation of pollutants, pesticides Modification of soil structure Biological regulation of pest species Ecological goods and services

But First- What Do Plants Do for Soil Organisms? • Allocation of energy greater to roots forages • 40 -65% of plant weight below ground • 12 -20% of root carbon goes turns into soil organic matter

Soil Organisms Like to be Near Roots # Bacteria / m. L soil 1 5 10 15 20 120 000 000 96 000 000 41 000 000 34 000 000 13 000 000 Source: Paul and Clark, 2001, Soil Biology and Biochemistry Number of soil organisms Distance from Root (mm) Distance from root

Bacteria and Fungi Live Mostly Near Roots

Soil Food Web

Unhealthy Soil Food Web

Soil Organisms in Terms of Cows Holy Cow! There’s 20 down there!

Bacteria • Dominant microorganism in tilled soil • Decompose residue releasing nutrients • Make available sulfur for plant uptake (sulfur oxidizing bacteria) • Some can cause plant disease • Some can promote plant growth N cycling http: //www. fftc. agnet. org

Bacteria Look Different When in the Laboratory

Bacteria “Don’t Let Their Size Fool You” E. Coli swimming

Fungi

Fungi • • • Dominant microorganism in non-tilled soil Decompose residue releasing nutrients Release P from soil minerals Promote soil aggregation Some can cause plant disease Mycorrhizal fungi can promote plant growth by providing P and N to crops (not canola)

Mycorrhizal Fungi • Symbiotic association between fungi and plants • Plants provide organic energy • Fungus provides nutrients and water • Controlled infection of the plant • Several groups of diverse fungi capable of the association • Some plants unable to establish without mycorrhiza

Arbuscules and Intraradical Hyphae Kinden & Brown, 1975 17

Improved P Nutrition with Mycorrhizae Without Mycorrhizae (Jasper et al. 1994 )

Mycorrhizal Fungi After 13 Years of Organic Management Total Col Rotation Grain-Only Management Conventional Grain-Only Arb Col (%) 23 (11)1 32 (14) Organic 35 (4) 50 (4) Forage-Grain Conventional 16 (6) 28 (15) Forage-Grain Organic 35 (8) 45 (7) Forage-Grain Compost Conventional Forage-Grain Compost Organic 14 (4) 25 (8) 30 (8) 36 (8) Management ** * Rotation n. s. Interaction n. s. ANOVA tests Management and Rotation Welsh et al. in preparation

Aggregation 20 http: //helios. bto. ed. ac. uk/bto/microbes/arbuimag. htm

Fungi Build Soil Structure Water-stable Aggregates Bacteriacide * Fungicide No Biocides No Wheat Determined 14 days after wheat straw addition C/N =20 (Bossuyt et al. 2001; Applied Soil Ecology)

Crops Have Different Dependency Upon Mycorrhizae Mycorrhiza dependency Potential yield loss without mycorrhiza Very high greater than 90% High 60– 80% Sunflower, corn, peas, lentils, alfalfa, beans Medium 40– 60% Sorghum-sudan, soybean Low 10– 30% Wheat, barley, triticale, oats Very low 0– 10% Rye, buckwheat Nil 0 Crops Flax Canola From CSIRO, Australia

Canola Reduces Mycorrhizae and Yield in a Following Wheat Crop Thompson JP, Owen, KJ and Clewett, TG (2001) “Pre-cropping with canola decreases vesicular-arbuscular mycorrhiza and growth of wheat in a low phosphorus soil. Proceedings of the Second Australasian Soilborne Diseases Symposium. Porter IJ et al. (eds. ) pp 150 -151.

Role of Microbial Grazers • • Protozoa, nematodes, earthworms Release nutrients from bacteria and fungi Very important in no-till systems Check levels of pathogens and pests

Protozoa • Simplest eukaryotic organisms, are unicellular • Phagotrophic, motile 25

Protozoa

Rotifers

Nematodes

Plant Feeder Fungal Feeder Omnivore Rhabditid Bacterial Feeder Predator

Summary Nematode Analysis Of Manitoba Agricultural Soils 1. 0 Nematode Enrichment Group 0. 8 Potato Rotations Nematodes are great indicators of healthy soil – but they need to be identified Other Crop Rotations 0. 6 5 -yr fallow 0. 4 0. 2 Prairie Sites Tame Hayland La Broquerie 0. 0 0. 2 0. 4 0. 6 Nematode Structure Group 0. 8 1. 0

Microbial Nitrogen is Released From Bacteria and Fungi to Plants N+P N+P Soil organisms pooh too! Mineralization in intact cores by N isotopic dilution (Murphy, Sparling, Fillery, unpublished)

Nutrients Are Stored With Forages Because of build up of soil organic matter and microbial populations Grazed pasture Annual Rotations Bannerjee et al. 2001

Soil Organic Matter Living Organisms Plant Residues Humus Pre. Humus Total Organic Matter http: //www. globalsoilbiodiversity. org/

Impact of Perennials in Rotation on Soil Organic Matter Rotation Management Organic Matter % Grain-only Conventional 7. 2 (0. 2) Grain-only Organic 6. 7 (0. 5) Forage-grain Conventional 7. 9 (0. 5) Forage-grain Organic 7. 9 (0. 8) Forage-grain compost Conventional Forage-grain compost Organic Planted Prairie 8. 1 (0. 1) 8. 1 (0. 4) 8. 0 (0. 9) High productivity High root mass Lack of soil disturbance Promote soil organic matter buildup Source: Bell et al. 2012 Agron. J.

Soil Organic Matter Improves Corn Yield

Soil Organic Matter Decreases Some Diseases Tenuta et al. unpublished

Addition of Soil Organic Matter Improves Potato Yield Molina et al. 2014 Am Pot J

Ex. Compost and Potato Yield Fig. 2. CMCDC-Winkler Trial: Potato (Russet Burbank and Umatilla Russet) yield in response to cattle manure compost added to saline and non-saline locations in 2009. (Cavers et al. , unpublished) Fig. 3. CMCDC-Winkler Trial: Potato (Russet Burbank) yield in response to cattle manure compost (37 g ha-1) and mustard meal added to non-saline soil in 2009. (Cavers et al. , unpublished)

CO 2 Flux (NEE)

C Budget (Mg ha-1) Continuous Annual 115. 2 Mg C ha-1 to 30 cm 4% organic carbon drop of Amount at start of study! Annual + Perennial Phase Annual Perennial

What Can You Do to Grow Soil Organisms? • Rotate wisely • Increase organic matter in soil – High biomass crops, perennials, reduce tillage, cover crops, use animal manures • Mindset - you are also “Growing Soil” • Feed soil • Make it part of annual farm plans and EFP to build your soil through critters below ground

How Do I Know if My Soil is Getting Better? • Track in time soil tests for: soil organic matter, inorganic nutrients, yield, protein • Post harvest soil N test • Spring soil N test • Observe improvements in structure, infiltration • Track diseases • Track input/output

Working with an Industry Research Station to Trach Soil Health

Tests • The Underwear Test • Laura Van Eerd, U Guelph, Ridgetown

Thank You For Looking at Soil Organisms With Me

Cornell Active Soil Carbon Test The relationship between above-ground dry matter yield of corn in 36 onfarm plots in Lavanderos Honduras and the soil content of active C (left) or total C (right). Weil et al. 2003. J. A. A. 18: 3 -17

Solvita Soil Health Tests A) CO 2 burst – microbial biomass, dried soil and then moistened B) Basal respiration – 3” core into jar for 1 to several days C) Solvita Labile Amino Nitrogen Test SLAN Na. OH added to soil to release ammonia

• • Cornell Soil Health Test Particle size for texture Wet aggregate stability Available water holding capacity Surface hardness Organic matter Active carbon (dilute 0. 2 M KMn. O 4) Fertility test (p. H, lime requirement, extractable P, K, Ca, Mg, Al, Fe, Zn, Mn) • Potentially mineralizable N (anaerobic incubation, autoclaved citrate extractable protein) • Root health bioassay

Cornell Soil Health Test Report Notice, conventional soil test N not included

Visual State Assessment VSA Test • New Zealand • Visual scores 0 (poor), 1, 2 (good) • Some soil conditions weighted more than others (soil structure > clods) • After harvest but soil can’t be too wet • 20 cm cube of soil, dropped three times, separate aggregates (clods) from large to small and visually rate conditions

VSA Score Sheet Focuses on soil structural properties of soil

VSA Soil Structure

VSA Soil Porosity

Soil Food Web Inc. Test • • • Assumption fungi are better for crop production than bacteria Active bacteria to total bacteria Active fungi to total fungi Protozoa (flagellates, amoebae, ciliates) Nematodes (feeding groups) Nitrogen Cycling Potential because of Protozoa and Nematode feeding • Root Mycorrhizal Colonization

Earthworms • • • Omnivore Break down residue – pulling it into soil Accelerate nitrogen release Increase soil aeration (Bioturbation) Accelerate pesticide degradation Increase soil aggregation Promote drainage Bioindicator of poor soil health You can catch fish with them

Earthworms Increase with No-till and Grassland Source: Jon Simonsen, Wisconsin Integrated Cropping Systems Trial

58 Dendrobaena octaedra

Interesting Observation Charles Darwin wrote that an acre of good soil contains 63, 000 earthworms, they will bring to the surface 2” of new top soil every 10 years!