Northern Soil Amendment Trial
Background Information
Deciding which amendments to use is always a challenge as farmers must consider the transportation
and application of products, the availability of local products, and the increasing cost of fertilizer and
shipping. The four major amendments being studied are synthetic fertilizer (NPK), organic fertilizer
(ORG), city compost (COM), and city compost with lime (C&L). In 2011, biochar was added in
combination with each of the other four treatments and plots with humic acid were added in 2012.
Different vegetables are grown in rotation each year starting with beets in 2010, carrots in 2011, kale in
2012, peas in 2013, and back to beets this year.
^
N
Map
2m
Synthetic Fertilizer
Synthetic Fertilizer & Humic Acid
Synthetic Fertilizer
2m
Organic fertilizer & Humic Acid
Organic fertilizer & Biochar
Organic fertilizer
2m
Compost & Lime
Compost, Lime & Humic Acid
Compost & Lime
2m
Compost & Lime
Compost, Lime & Biochar
Compost & Lime
2m
Compost & Lime
Compost & Lime
Compost & Lime
2m
Compost
Compost & Humic Acid
Compost
2m
Southwest Corner of Irrigated Field
Compost
Compost & Biochar
Compost
10 m
10 m
10 m
Amendment addition schedule
Amendment
Synthetic Fertilizer (NPK)
Organic Fertilizer (ORG)
Compost (COM)
Compost and Lime (C&L)
Biochar
Humic Acid
2010
100 Kg/ha N
20 Kg/ha P
50 Kg/ha K
100 Kg/ha N
20 Kg/ha P
50 Kg/ha K
45 t/ha
45 t/ha + 6.7
t/ha lime
0 t/ha
0 t/ha
2011
100 Kg/ha N
20 Kg/ha P
50 Kg/ha K
100 Kg/ha N
20 Kg/ha P
50 Kg/ha K
40 t/ha
2012
100 Kg/ha N
20 Kg/ha P
50 Kg/ha K
100 Kg/ha N
20 Kg/ha P
50 Kg/ha K
35 t/ha
2013
0 Kg/ha N
45 Kg/ha P
125 Kg/ha K
0 Kg/ha N
45 Kg/ha P
125 Kg/ha K
40 t/ha
2014
100 Kg/ha N
20 Kg/ha P
50 Kg/ha K
100 Kg/ha N
20 Kg/ha P
50 Kg/ha K
45 t/ha
40 t/ha
35 t/ha
40 t/ha
45 t/ha
10 t/ha
0 t/ha
10 t/ha
0.44 t/ha
0 t/ha
0.44 t/ha
0 t/ha
0 t/ha
Fertilizer background information
The costs listed here are for commercial volumes and landed in the Yukon, costs of fertilizers vary every year, but
with an upward trend over time.
Synthetic Fertilizers
Nitrogen (Urea 46-0-0)
Phosphate (Triple
Superphosphate 0-45-0)
Potassium (Potassium
sulphate 0-0-50)
Supplier: Agrium
Cost: $1 per kg
Supplier: Agrium
Cost: $1 per kg
Supplier: Agrium
Cost: $1.25 per kg
Synthetically formulated
Aka: NH2CONH2, CO(NH2)2, carbamide
 95.5-97.5% Urea: nitrogen, hydrogen, oxygen and
carbon

1-1.5% Biuret (result of condensation of urea
molecules - different organization of N, H, C and O)

.1-.4% water
Synthetically formulated
Aka: GTSP, Concentrated superphosphate, calcium
bis(dihydrogenorthophosphate)
 58-95% Superphosphates, concentrated (P2O5)

1-20% Calcium sulphate (CaS04)

0.1-15% Calcium hydrogen orthophosphate
(CaHPO4)

0.1-10% Fluorapatite (Ca5(PO4)3F)

0.1-5% Orthophosphoric acid (H3PO4)
Mined Product
Aka: K2SO4, sulphate of potash, SOP
 10-15% Potassium hydrogen sulfate (KHSO 4)

>85% Potassium sulphate (K2SO4)
Organic Fertilizers
Bloodmeal (12-0-0)
Bone Meal (2-14-0)
Potassium (Sulphate of
potash 0-0-50)
*This is both used in
synthetic and organic
fertilizer blends
Supplier: Gaia Green
Cost: $2.25 per kg
Supplier: Agrium
Cost:$2 per kg
Supplier: Agrium
Cost: $1.25 per kg
Animal byproduct
Components of Vertebrate Blood
 Proteins: made of amino acids
o Carbon group, Hydrogen (-H), carboxyl
group (-COOH), amino group (NH2) and
unique side chain or R-group
 Fatty Acids: Chains of carbon, hydrogen and oxygen
 Urea: CO(NH2)2
 Nutrients and vitamins in trace amounts including
Ca, Fe, and P
 Glucose: C6H12O6
 Hormones
 Electrolytes: Na+, K+, ClAnimal byproduct
 High in phosphorous and calcium

Collagen - protein

Carbonated hydroxyapatite Ca10(PO4)6(OH)2
Mined Product
Aka: K2SO4, potassium sulphate, SOP
 10-15% Potassium hydrogen sulfate (KHSO 4)

>85% Potassium sulphate (K2SO4)
Compost
City of Whitehorse Compost, from Boreal Compost Enterprises, LTD.
Cost: 1 to 9 cubic yards: $45/yard, and 10 or more cubic yards: $25/yard.
Note: One cubic yard = 3x3x3 feet = 1600 pounds ≈ one pick-up truck load.
The composting produced at the Whitehorse compost facility is commonly known as hot aerobic composting.
For more information: www.borealcompost.ca
Lime
Addition of Garden Green Lawn and Garden Lime, a pulverized limestone with a minimum 38% Ca and 97% CaCO3.
Liming soils is common practice in other areas of the world where it counteracts acidification of soils. Our soils have
a high pH and general sufficient Calcium, has the lime helped the garden grow? Cost is approximately $1 per kg.
Humic Acid
Humic acid is a naturally occurring component of soil that is formed by the microbial decomposition of organic
matter. Once in this form, humic acid is very resistant to further chemical breakdown. In addition to naturally
synthesized form, humic acid can also be extracted from mineral deposits similar to coal. The commercially mined
humic acid is sold as a soil amendment product that has been linked with assisting the breakdown of compacted
soils, helping the absorption and transfer of macro- and micronutrients, and encouraging the development of soil
microbes.
As compost is formed by the decomposition of organic matter, it already contains humic acid. There are concerns
about the quality of compost in 2012 and this could have helped mitigate this problem. Humic acid will continue to
be studied in 2013’s soil amendment trial and it will be interesting to see if humic acid increases yields even when
the compost is better quality.
Cost of humic acid varies dramatically, but expect to pay $10 or more per kg. Is the cost worth it?
Biochar
Biochar is essentially charcoal – the black, partially combusted remnants commonly found in a woodstove or after a
campfire. Biochar is created when the heating of organic matter occurs with minimal oxygen – without the oxygen,
carbon molecules cannot gas off as carbon dioxide and remain in solid form. The technical name for this process is
pyrolysis.
Cost of biochar varies dramatically, expect to pay about $2 per kg.
Graph of results from previous years