Proposed Biological Program for Blueberry

  • Blueberry
  • Blueberry
  • Blueberry farm

 This program has been developed by Soil Foodweb Inc through close consultation with active growers of the North American Blueberry farming industry. It has been reproduced with the permission of Soil Foodweb Institute by AgriSense for your information, AgriSense welcomes your comment and suggestions regarding this program and the proprietor, being a Certified Soil Foodweb Adviser is only too pleased to discuss any concepts or points raised in this article with you.

1.Use areas without weed mat cover

2.Start after this season's harvest is finished, or start improving the soil after all toxic chemical applications have been applied

All compost used must have the following MINIMUM characteristics:

1. Earthy mushroom smell

2. Visible to the un‑aided eye fungal strands in the compost

3. Moisture around 45 to 50%

4. Active bacteria biomass greater than 15 µg/g compost

5. Total bacterial biomass greater than 100 µg/g compost

6. Active fungal biomass greater than 15 to 20 µg/g compost

7. Total fungal biomass greater than 300 µg/g compost

8. Average hyphal diameters equal to or greater than 2.5 um,

9. Protozoan numbers (sum of flagellates and amoebae) greater than 20,000/g compost

10. Less than 500 ciliates per gram compost

11. Nematodes greater than 5 beneficial nematodes per gram compost


a rating of VERY GOOD to EXCELLENT must be obtained using a qualitative SFI assessment

All compost teas used must have the following MINIMUM set of characteristics:

1 . Brown colour to the tea

2. Documented oxygen levels in the tea during brewing

3. Active bacterial biomass above 10 µg/ml of tea

4. Total bacterial biomass above 150 µg/mI tea,

5. Active fungal biomass above 2 µg per ml tea

6. Total fungal biomass above 20 µg/ml tea,

7. Average hyphal diameters equal to or greater than 2.5 µm,

8. Protozoan numbers (sum of flagellates and amoebae) greater than 2,000/mI tea,

9. Less than 50 ciliates per ml tea


A rating of GOOD to EXCELLENT must be obtained using a qualitative SFI assessment.

Mulch should be chipped (25% left at greater than 2 cm chunk sizes) woody materials kept in a windrow and left alone as much as possible except to add in inocula of any highly fungal compost, soil, or "left‑over" compost tea. The windrow can be extended as much as desired, but new materials should not be mixed into old materials. Instead, new material is added to the end of the pile, and inocula from the older material put into the newer material.


1. Three weeks before harvest, perform the following assessments:

v  a .Do a soil penetrometer reading and document depth to which the metal rod will move into the soil, and the pressures associated with pushing the rod into the soil.

v  b. Dig into the soil to that depth, and assess root depth. Take pictures.

v  c. Perform and document a water infiltration assessment at the soil surface.

v  d. Look for and record amount of visible fungal hyphae in the soil.Per handful of soil and litter examined, how many of those handfuls have visible fungal hyphae?

v  e. Take samples to assess soil biology (SFI Full Foodweb), and soil chemistry (EAL Soluble and Exchangeable and Total Extractable).

2. Look at results of testing biology and chemistry.

3. Determine what additional nutrients might be needed to be added to the compost or to teas, depending on choice of material placed in the field.


4. Apply EITHER 2.5 ton aerobic compost/HA (see criteria above) or 150 to 200 L compost tea/HA (see criteria above) to the soil around the stems of the blueberry plants.

5. One month after application of compost or tea, as long as temperature has mostly been above 10 C, and moisture levels have been above 15%, then perform the following tests:

6. Assess litter decomposition rates.

  1. Mark five fresh fallen leaves on the soil surface with flags
  2. 4 weeks later, return and assess amount of the leaf material decomposed
  3. At least 50% of each leaf should be gone. If not gone, then reapply biology.

7. Assess soil penetrometer changes.

v  Penetrometer should move into the soil at least twice the depth it previously moved into the soil before reaching 300 psi

v  If this doesn't happen, then reapply biology

8. Assess visible fungal strands. If visible strands have not increased by double, then reapply biology.

9. Perform a qualitative assessment of biology in the soil. Soil should reach minimum levels for total bacterial biomass, total fungal biomass and protozoa.

10. Continue this loop until all three parameters are successfully met, using the initial soil tests as the "zero point", or if weather does not cooperate, assess after two months.

11. In the spring, at bud swell, apply an application of 150 L/HA of compost tea to the soil at the base of the blueberry stems, spreading out across the entire planting mound. Make this compost tea absolutely as fungal as possible. This will help prevent grasses and weeds from moving up onto the soil.

12. Apply 5 cm depth of highly woody mulch to the soil surface as a weed barrier.

13. First foliar compost tea application (50 L/HA) occurs at bud break.

  1. Assess leaf coverage to make certain leaf material is receiving 70% or better coverage of both bacteria and fungi
  2. If coverage is lacking, determine where biology is being lost and fix the problem

14. Assess foliar disease conditions.

v  If disease is appearing (if the soil applications have been effective, 70% of any disease, fungal, insect, viral, etc should have been removed), then begin to apply tea weekly.

b. Add specific bio‑control agents to the tea to deal with any particular disease or insect problem.

v  Beauveria, Bacillus and/or Heterorhabditus (need specific species for the specific insect problem) to deal with soft‑bodied insects

v  Trichoderma, Gliocladium, milky spore to deal with fungal disease outbreaks

v  Pseudomonas to deal with chemical residue problems assessed by leaf curling problems

v  Nematode bio‑controls for soil insects, root‑feeding nematode problems (Steinernema, 13F, FF, predatory nematodes, mycorrhizal fungi)

v  v. Ericoid mycorrhizal fungi to deal with lack of nutrient availability in soil, poor disease suppression in soil

v  15. Apply tea monthly to maintain leaf surface coverage. Assess leaf coverage.

16. If disease appears, begin weekly applications until disease problem ends.

17. When fruit is present on bush, minimize use of humic acids in the foliar compost tea applications as humic acid may spot the fruit.


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