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