Keeping the Place
Fertile
Organically!
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Techniques
◦ Crop rotation
◦ Green manuring
◦ Mulching
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Additives
◦ A bit of Chemistry NPK & pH
◦ Home made/gathered
◦ Bought in
What will we be talking
about?
Essentially don't keep growing the same
stuff in the same ground
 It maintains fertility and prevents a
build up of pests and diseases
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Roots, followed by –
Legumes, followed by –
Leaf, followed by –
Other e.g. solanum or brassica crops or lie
fallow.
Can be difficult to do in a small area
Crop Rotation
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Adding a thick organic layer on top of the
soil and planting through it.
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Keeps soils surface cool & protected
Conserves moisture
Suppresses weeds
Prevents soil compaction by rain
Examples – hay, straw, compost, grass
clippings, sawdust/wood shavings; animal
manures
Mulching
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This is the process of growing a crop, then
digging it in to provide organic matter
Dig in before flowering
Allow to break down for a few
weeks before planting
Legumes fix nitrogen as well
Other crops include –
buckwheat; mustard; oats; rye; lucerne
Green Manuring
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3 Major Nutrients
◦ Nitrogen; Phosphorous; Potassium (NPK)
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3 Secondary Nutrients
◦ Calcium; Sulphur; Magnesium
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6 Minor (Trace) Nutrients
◦ Iron; Manganese; Copper; Zinc; Boron;
molybdenum;
N for foliage
 P for Plant growth, flowers and Fruit
 K for strong disease resistant plants
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A Bit of Chemistry
Material
N
P
K
Human urine
15-19
3-5.4
1-2.5
Blood and bone
3-6
8
10-20
Worm Castings
3.2
1.1
1.5
Pigeon manure
4.19
2.24
1.41
Chook manure
1.63
1.54
0.85
Horse manure
0.44
0.17
0.35
Cattle manure
0.29
0.17
0.10
Dried coffee grounds
1.99
0.36
0.67
Lucerne hay
2.45
0.5
2.10
Grass clippings
1-2
0-0.5
1-2
Wheat straw
0.5
0.15
0.18
Wood ash
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1.5
5-15
NPK of Common Materials
What about pH?
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Compost
Wood ash
Seaweed/kelp
Worm castings
Poultry manure
Urine
Liquid manure
Home made/gathered
Blood and bone
 Rock dust
 Horse/Cow manures
 Dolomite & gypsum
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Store Bought
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Making liquid worm castings
You need 20 litre bucket, worm castings,
molasses, fish emulsion, aquarium aerator
Make a tea bag with 500gms worm
castings & soak in bucket overnight
Remove bag add 200g molasses, 20g fish
emulsion and stir well
Connect aerator and aerate until the
batch foams up.
Apply by watering can after sun is down
Biological Fertility
Improvement
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Making a low tech worm farm
Burn holes in bottom of top broccoli box
with soldering iron.
Put down shade cloth in the bottom, fill
with cocopeat and place hessian on top
Cut hole in the end of the bottom broccoli
box and use silicon to secure top cut from
PET bottle in the hole as a tap
The farm is ready for worms
Practical
For more details check our website