Benefits of Compost Use
David AllenMBS Environmental
Chemistry Physics
Biology
•Water Retention•Drainage•Aeration•Compaction
•Nutrient Supply•Nutrient Retention•pH Control
•Nutrient Recycling•Disease Control
Improving Physical Properties of Soils:Improving Physical Properties of Soils:•Improving water holding capacity•Reducing bulk density of compacted soils•Reducing clay dispersion in hard-setting soils•Improving drainage
•Improving water holding capacity•Reducing bulk density of compacted soils•Reducing clay dispersion in hard-setting soils•Improving drainage
Improving Biological Properties of Soils:Improving Biological Properties of Soils:•Provides nutrients and energy for soil flora and fauna•Increases nutrient recycling•Reduces plant pathogens and diseases
•Provides nutrients and energy for soil flora and fauna•Increases nutrient recycling•Reduces plant pathogens and diseases
• Supplies nutrients• “Unlocks” stored soil nutrients • “Slow-release” properties• Balanced nutrient profile• Improves effectiveness of added fertilisers
oIncreases nutrient retention (cations and trace elements)oReduces leaching losses of mobile nutrients
• Maintains near-neutral pH values:oLime effect on acidic soilsoReduces effects of soil alkalinity
• Supplies nutrients• “Unlocks” stored soil nutrients • “Slow-release” properties• Balanced nutrient profile• Improves effectiveness of added fertilisers
oIncreases nutrient retention (cations and trace elements)oReduces leaching losses of mobile nutrients
• Maintains near-neutral pH values:oLime effect on acidic soilsoReduces effects of soil alkalinity
Improving Chemical Fertility of Soils:
Quindalup Sand Spearwood Sand Bassendean sand
Forms of Nutrients in Compost
Incorporated into organic matter.(Carbon, nitrogen, phosphorus, sulphur)
Adsorbed onto organic matter surface.(Potassium, ammonium-N, calcium, boron, copper, zinc)
Inorganic minerals(Calcium, phosphorus, sulphur)
Water-soluble Salts(Sulphate-S, nitrate-N, soluble reactive phosphorus, chloride)
Comparison of Nutrient Content with Other Organics and FertilisersNutrient Units Compost Biosolids Cow
ManurePoultry Manure
Urea Super-phosphate
Nitrophoska
Nitrogen % 2.1 5.91 1.60 4.26 46 15
Phosphorus % 0.89 2.48 1 to 3 9 3.9
Potassium % 1.3 0.28 1.5 to 2.5 12.4
Calcium % 3.0 2.16 22 3.4
Magnesium % 0.39 0.79 1.2
Sulphur % 0.64 0.16 0.5 to 1.0 10 6.0
Boron mg/kg <100 49 9 18 100
Copper mg/kg 100 1000 35 51
Iron mg/kg 1700 6800 3000
Manganese mg/kg 300 100
Molybdenum mg/kg <10 18 1.2 1.5
Zinc mg/kg 400 1000 90 310 400 70
Nitrogen
Parameter Units A B C D E F
Carbon % 10.6 13.7 32.7 43.5 11.8 25.4
Nitrogen % 1.1 1.8 2.7 2.1 0.83 1.44
C : N ratio 9.6 7.7 12.2 21 14.4 17.6
NO3-N mg/L 115 343 3.6 1.4 15.8 34
NH4-N mg/L 1.0 0.43 407 0.32 0.18 74
Phosphorus
Parameter Units A B C D E F
Total P % 0.36 0.99 1.4 0.89 0.22 0.72
Extractable P % 0.19 0.40 0.57 0.29 0.126 0.29
Water-soluble P mg/L 4.3 4.6 59 15.7 9.5 1.55
Cations
Parameter Units A B C D E F
Total Ca % 1.5 3.5 4.3 3.0 1.5 3.6
Extr. Ca % 0.82 1.5 1.4 1.3 0.86 2.1
Total Mg % 0.28 0.46 0.40 0.39 0.19 0.27
Extr. Mg % 0.20 0.34 0.30 0.31 0.15 0.21
Total K % 0.53 0.77 1.0 1.3 0.27 0.27
Extr. K % 0.40 0.57 0.74 0.95 0.21 0.25
Total Na % 0.17 0.23 0.37 0.51 0.09 0.14
Extr. Na % 0.12 0.14 0.26 0.42 0.06 0.11
Trace Elements
Parameter Units A B C D E F
Total B mg/kg <100 <100 <100 <100 <100 <100
Extr. B mg/kg 4 6 18 12 12 13
Total Cu mg/kg <100 30 400 100 30 300
Extr. Cu mg/kg 3 2 58 19 8 9
Total Mn mg/kg 200 200 300 300 100 100
Extr. Mn mg/kg 94 130 160 110 47 50
Total Zn mg/kg 90 180 600 400 200 300
Extr. Zn mg/kg 58 110 380 290 120 200
Water Holding Capacity
Parameter Units A B C D E F
Water Holding Capacity % 47 52 53 61 61 -
pH Control
Parameter A B C D E F
pH 7.6 7.7 8.4 6.9 8.4 6.4
Cations AnionsBefore composting
AnionsAfter composting
Calcium
Magnesium
Potassium
Sodium
Organic anions
Phosphate
Sulphate
Nitrate
Alkalinity
A Year in the Life of a Phosphate Molecule
January
A Year in the Life of a Phosphate Molecule
February - March
A Year in the Life of a Phosphate Molecule
October - November
A Year in the Life of a Phosphate Molecule
December
Landfill
Application Rates
Intended Use Application Rate(cubic metres per hectare)
Increasing water holding capacity 50 to 200
Improving soil structure 20 to 100
Countering acidity/alkalinity 20 to 50
Long term nutrient supply 20 to 100
Short term nutrient supply 5 to 20
Improving soil biology <1 to 50