Amendment Comparison
Smart Sludge is an organic soil amendment. This page shows the difference between other organic amendments and Smart Sludge. Amendments can be landspread according to a set of government approved guidelines. Recommended application rates of different organic amendments can be seen in the chart below based on tonnes per hectare:

Range of nitrogen application per tonne of recommended applied amendment:

Benefits and Drawbacks
Smart Sludge
- Benefits
- High organic matter content
- Improved soil structure
- Increased porosity, aeration, drainage and rooting depth on fine textured soils
- Increased water holding capacity
- Slow release of nitrogen
- Increased nutrient holding capacity
- Can be applied on slopes up to 15%
- Can reapply after 2-4 years if requirements are met
- Reduces amount of waste incinerated or landfills at pulp and paper mills
- Drawbacks
- Since SmartSludge is high in nitrogen content, improper landspreading may cause excessive nutrient loading or nutrient imbalances
- Only recommended for soils with pH > 6.5
- Odors
- Heavy metals
- Applicable Guidelines/Regulations
Biochar
- Benefits
- Enhances crop productivity
- Reduces bulk density and increased porosity
- Reduces nutrient leaching
- Reduces soil acidity
- Improves fertilizer efficiency
- Reduces soil erosion
- Provides micro-environment for soil microbes to grow
- Drawbacks
- Expensive to make and ship
- Energy intensive to make
- Large volumes needed due to low bulk density
- Loss due to wind
- May contain PAHs or heavy metals
- May be detrimental to some microbial fauna
- Applicable Guidelines/Regulations
Manure
- Benefits
- Increased crop productivity and yield
- Source of nutrients
- Provides nitrogen throughout the season
- Increases microbial activity
- High organic matter content
- Improved soil structure
- Increased water filtration and water holding capacity
- Increased cation exchange capacity
- Reduced wind and water erosion
- Drawbacks
- Moisture and nutrient contents are very variable
- Nutrients in manure are rarely balanced resulting in excessive nutrient loading or imbalances
- Odor
- Pathogens
- Expensive to move large distances
- Applicable Guidelines/Regulations
Compost
- Benefits
- High organic matter content
- Source of nutrients
- Improves soil structure
- Increases water holding capacity
- Supplies beneficial soil microbes
- Pathogen free
- Weed seed free
- Drawbacks
- Must be used on a case by case basis as guidelines for compost application are not made
- Applicable Guidelines/Regulations
Digested Biosolids
- Benefits
- High organic matter content
- Improved soil structure
- Increased water holding capacity
- Source of nutrients
- Low cost
- Can reapply after 3 years if requirements are met
- Reduces landfilling
- Drawbacks
- Pathogens
- Heavy metals and other contaminants
- Excessive nutrient loading or nutrient imbalances is biosolids are improperly applied
- Only recommended for soils with pH >6.5
- Can only be applied on slopes up to 9%
- Odors
- Applicable Guidelines/Regulations
Wood Ash
- Benefits
- Acts as a liming agent
- Increases soil fertility
- Potential to reduce infestations of unfavorable crops
- Increased rate of decomposition and nutrient cycling
- Supplies phosphorus to soils
- Drawbacks
- No nitrogen content
- Loss due to wind
- Fine particle size
- Must be incorporated into soil
- Applicable Guidelines/Regulations