Managing Soil Health for Nematode Control

Transcription

1 Managing Soil Health for Nematode Control Dr. Daniel K. Manter, USDA-ARS, Fort Collins, CO Dr. Jorge Vivanco, CSU, Fort Collins, CO Jeannine Willett, Agro Engineering, Alamosa, CO

2 USDA NRCS Soil Health Division Why Soil Health? Physical Soil Health Chemical Biological Soil is a living system that supports a diverse, active biological community that aids crop production by providing SOM formation/decomposition Enhanced nutrient cycling Improved soil structure Improved H 2 O & nutrient holding capacity Protecting plants from disease & pests Protecting plants from stress Detoxification of pollutants

3 Soil Health Principles to Optimize Biological Communities & Functions Feed & Fuel Soil Biology Protect Soil Aggregate & Organic Matter USDA NRCS Soil Health Division

4 Soil Health Principles Minimize Disturbance & Maximize Cover Maintain stable aggregates Reduce erosion and runoff risk Buffer temperature Reduce evaporation Maintain soil organic matter Protect & Preserve USDA NRCS Soil Health Division

5 Soil Health Principles Feed & Fuel Maximize Biodiversity & Maximize Living Roots Increase soil organic matter quantity & quality Break disease/pest cycles Stimulate/change belowground diversity Increase nutrient cycling Enhance plant growth Increase predator & pollinator populations USDA NRCS Soil Health Division

6 Management Practices that Feed & Protect Crop Rotation Cover Crop Relay Crops Forage & Biomass Planting Perennial Crops Reduced Tillage Controlled Traffic Avoid Tillage When Wet No-till Cover Crop Crop Rotation Rotational Grazing IPM Pollinator plantings Organic fertilizers Legumes in mix Cover Crop Mulching Reduced Tillage Forage & Biomass Planting Residue Retention USDA NRCS Soil Health Division

7 Integrated Soil Health Management 1. Knowledge Typical problems 2. Initial Assessment Current status Who s there 3. Thresholds for Action What are acceptable levels? Is more always better 4. Management Chemical/Physical/Biological 5. Re-assessment Success Cost-effective Re- Assessment Management Integrated Soil Health Management Thresholds for Action Knowledge Initial Assessment

8 USDA NRCS Soil Health Division Why Soil Health? Physical Soil Health Chemical Biological Supports diverse, active biological communities that aid crop production via: SOM formation/decomposition Enhanced nutrient cycling Improved soil structure Improved H 2 O & nutrient holding capacity Protecting plants from disease & pests Protecting plants from stress Detoxification of pollutants

9 Pest/Pathogen Nematode Damage Host Environment

10 Pest/Pathogen Nematode Damage Host Physical Soil Health Chemical Biological

11 Microbial Nematode Interactions Bacteria are the food source for free-living nematodes. However, they are also potential biocontrol agents regulating community structure and plant parasitic nematodes Mode of Action Parasitic Opportunistic parasitic Rhizobacteria Genus Pasteuria Brevibacillus Bacillus Pseudomonas Agrobacterium Arthrobacter Lysobacter Rhizobium

12 Nematicidal Microbes - Bacteria Pasteuria penetrans

13 Nematicidal Microbes - Fungi Meria coniospora Catenaria anguillulae

14 Integrated Soil Health Management 1. Knowledge Typical problems 2. Initial Assessment Current status Who s there 3. Thresholds for Action What are acceptable levels? Is more always better 4. Management Chemical/Physical/Biological 5. Re-assessment Success Cost-effective Re- Assessment Management Integrated Soil Health Management Thresholds for Action Knowledge Initial Assessment

15 2016 SLV Survey June 20, 2016 Five farms with historically different nematode levels. GB Sargent Mosca organic Mosca Hooper Nematode community assessment (direct counts) Blanca Bacterial community assessment (16S rrna)

16 Plant Parasitic Nematodes Sargent 16b 15b 1a Mosca II 14ab 9ab 1a Mosca I 18b Monte Vista 18b 19b Blanca 7a 1a 1a Pratylenchus Meloidogyne Paratrichodorus

17 Total Microbial (Bacteria) Biomass

18 Nematode Biocontrol Agents Targeted approach Compared the abundance of 36 genera known to be potential biocontrol agents genera highest at Blanca (i.e., lowest plant parasitic nematodes) Log-transformed Total Abundance (16S rrna copies / g soil) Genera Blanca W Gun Mosca I Mosca II Sargent p-value Agrobacterium Arthrobacter <0.001 Bacillus <0.001 Lysobacter Pseudomonas Rhizobium Opposite trend as total bacteria biomass. Illustrates importance of a thorough assessment.

19 Nematode-Microbe Interactions in the San Luis Valley, Potato fields Nine farms with long field sampling histories MANAGEMENT CONDITIONS: Farms - organic or sustainable vs. conventional Green manure history vs. barley or potatoes Microbial inoculants vs. no treatment Vydate vs. microbial inoculants Non-crop ground vs. potato crop

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21 Bacillus vs Meloidogyne Nematode Count r = 0.31 Bacillus is the only bacterial genus consistently negatively correlated with Meloidogyne presence (2016 & 2017) E E E E E E E+07 Bacillus Abundance

22 Integrated Soil Health Management 1. Knowledge Typical problems 2. Initial Assessment Current status Who s there 3. Thresholds for Action What are acceptable levels? Is more always better 4. Management Chemical/Physical/Biological 5. Re-assessment Success Cost-effective Re- Assessment Management Integrated Soil Health Management Thresholds for Action Knowledge Initial Assessment

23 Bacillus Abundance by Biological Amendment 2.50E E+07 Bacillus Abundance 1.50E E E E+00 BioBlend BioFitN MeloCon None 37 3 Paecilomyces Bacillus strains

24 Bacillus Abundance by Cultivar 4.50E E+07 Bacillus Abundance 3.50E E E E E E E E+00

25 Previous Cover Crop Study in the SLV

26 Integrated Soil Health Management 1. Knowledge Typical problems 2. Initial Assessment Current status Who s there 3. Thresholds for Action What are acceptable levels? Is more always better 4. Management Chemical/Physical/Biological 5. Re-assessment Success Cost-effective Re- Assessment Management Integrated Soil Health Management Thresholds for Action Knowledge Initial Assessment

27 Management: Putting it All Together Feed the microbes Cultivars Cover crops Biologicals Bacillus strain Paecilomyces/Bacillus interaction Cultivar/Bacillus combinations Controlled field trials to validate success On-going analysis from 2017 survey soil health indicators (e.g., Haney test and microbial community PLFA and 16S/18S)