Slides - ACORN Organic Conference

Soil
Amendments:
How to Find
and Apply
Rupert Jannasch and
Roxanne Beavers
Considerations for
Organic Growers
 The
basis of your fertility regime needs to
be from on-farm sources


Crop rotation, cover crops
Livestock
 Supplementing
can be done with
products allowed by the Permitted
Substances List
 Natural source, minimally processed
products
Amending your Soil
 How
do I know how much fertility is
needed?

Soil test, type of crop, contribution of green
manure and organic matter
 Nutrient
availability from most organic
amendments is a gradual process driven
by microbes
Sources of N: Manure
 Source
of nitrogen and organic matter
 Composted is preferable, and if not organic,
composting may be required
 Non-composted manure must be applied far
before harvest (90-120 days)
 Nutrient levels depend on animal source,
moisture content, bedding
 Raw manure should be incorporated to
minimize N losses
Manure Source
% N (dry
weight)
Release Rate
Dairy
1.5
medium
Steer
1.7
medium
Layer
3.2
high
Pig
3.5
medium high
Compost (mixed 1
source)
low
www.uky.edu/Ag/Horticulture/manures.htm
Composts
 Why
use compost instead of raw manure?
 Composting kills weed seeds, pathogens,
stabilizes nutrients
 Provides macro and micro nutrients
 Adds organic matter to soil which makes it
better able to hold nutrients
 Increases microbial activity which makes
nutrients more available
Composts
 Made


on your farm?
Temperature must reach 55C for 2 days
Keep records of temp and turning
 Off-farm

compost?
Meet CCME Category A levels for trace
contaminants and criteria for acceptable
pathogen levels
 Both
– must use only allowed feedstocks
Other sources of N
 Alfalfa
Meal
 Soybean Meal (must be non-GMO)
 Crab Meal
 Feather Meal
 Blood Meal
 Pelletized Manures
More amendments
 Phosphorus
- Rock P, bonemeal
 Potassium – Greensand, wood ash
 Calcium – calcitic lime, calphos,
crabmeal/lobster meal/shells, ash, dolomitic
lime too
 Magnesium – dolomitic lime, Epsom salts /
magnesium sulphate
 Sulphur – elemental S, gypsum, Sul-Po-Mag, KMag
Micronutrients
 Required
in small amounts for plant
metabolism; high amounts may be toxic
 Boron, Copper, Iron, Manganese,
Molybdenum, Zinc
 Standard requires a soil test or plant tissue
test showing low levels before using
specific amendments
Micronutrients
 Amendments
might address one
deficiency (Solubor) or multiple
deficiencies





Kelp
Seaweed extracts
Basalt rock powder
Fish emulsions
Blended organic fertilizers
Is it Allowed?
 Check
the label/MSDS for ingredients
 Ask your Certifier
 If in doubt, contact the manufacturer

Get your answer in writing!
 Does

 Is
the product come from the US?
Must ensure that it doesn’t contain Chilean
Nitrate (will be phased out by 2013)
the Nitrogen analysis >3? Be cautious
How to Apply
 Composts
may be tilled in or used to topdress
 Manures must be incorporated, applied to
warm soil, avoid runoff
 Rock powders – apply early in season, or add
to composts
 Liquid products – can be used as a foliar
feed or a soil drench
 Need to determine your application rate
Application Rates
 Joe
has a 1 ac (0.4 ha) market garden
 He gets a truckload of 20 yards of
compost delivered – how much N will this
provide?


Assume 800 lbs/yard bulk density
7.2 tonnes of compost was delivered
 This
corresponds to a rate of 18 t/ha
compost
Application Rates
 Compost
analysis is 1.5 -1- 1
 20% of the N is available in the first year
(1.5)(20%) = 0.3%
 If

 If
18 t/ha compost is applied
then 54 kg N /ha is added
Joe is growing heavy-feeding crops or
has low background soil N, he will need to
add more N
Application Rates
 Soil
test for boron comes back low: 0.32
ppm
Want to add 1 kg/ha boron:
 Borax – 11% B


1 / 0.11 = 9 kg/ha or 0.9 g/m2
This product can be applied directly to soil
 Solubor

– 20% B
1/0.20 = 5 kg/ha or 50 g/100m2
 To
apply with a sprayer, use spray rate (e.g.
200 L/ha) to determine the area covered
by one tank
 10 L tank would cover 0.05 Ha or 500m2
 Multiply
this area by your application rate
to figure out what amount to mix in the
backpack - 250g/10L
Where to Source Products?
 Farm

supply stores
Consider delivery in bulk
 Regional
representatives for different companies
 ACORN Database
 Talk to other farmers
 Trade publications – Rural Delivery, Small Farm,
Canadian Organic Grower
Other Considerations
 OMRI
& Certifier Input Approvals
 Before you source, read the Permitted
Substances List to look for restrictions
 Questions?