Fertility Guidelines

Low-Medium Yield Potential Soils

CROP NITROGEN PHOSPHORUS (P​2O​5)
Grass
Seed
30 – 60 10 – 25
Forage 20% Legume
40 – 90
10 – 30   
Grass-Legume
20-40% Legume
30 – 65 20 – 30
40-60% Legume
10 – 30
20 – 40  
Legume
Greater than 60% Legume
0 – 30 30 – 50

Medium-High Yield Potential Soils

CROP NITROGEN PHOSPHORUS (P​2O​5) POTASSIUM(K2O) SULPHUR
Grass
Seed
30 – 70 10 – 30 30 – 50  0 – 10
Forage 20% Legume
60 – 100
10 – 30 50 – 60 10 – 15   
Grass-Legume
20-40% Legume
40 – 90 20 – 40 50 – 70 15 – 30
40-60% Legume
20 – 40
30 – 40 50 – 80 15 – 30   
Legume
Greater than 60% Legume
0 – 30 40 – 70 60 – 150 15 – 30

High Yield Potential Soils

CROP NITROGEN PHOSPHORUS (P​2O​5) POTASSIUM(K2O) SULPHUR
Grass
Seed
45 – 100 30 – 50 40 – 60 0 – 15
Forage 20% Legume
60 – 200
30 – 50 40 – 60 0 – 15   
Grass-Legume
20-40% Legume
60 – 80 40 – 60 60 – 80 15 – 20
40-60% Legume
0 – 60
40 – 80 80 – 150 15 – 30   
Legume
Greater than 60% Legume
0 – 50 60 – 100 80 – 200 20 – 30

*Residual response to the higher rates may persist for two years, particularly when the year of apllication is dry and production is low. Therefore annual application may not always be necessary.

Source: Adapted from various U.S State and Canadian Prairie Province Extension Bulletins.