Energy flow in ecosystems:

improving yields and profitability

Energy Flow and Ecosystem Cycles

Linear

• Energy Flow

Cyclical

• Nitrogen Cycle

• Carbon Cycle

• Water Cycle

• Soil Nutrient Cycle

Energy Flow Pyramid

• 90% of energy lost from the ecosystem as heat, as it moves from one trophic level to another.

Plants

Herbivores

carnivores

carnivores

Scavenger/decay

decay Layer 6 1mm Layer 5 1cm Layer 4 10cm Layer 3 1 metre Layer 2 10 metres Layer 1 100 metres!

Plants determine the scale

Time Period of active growth. Speed of growth

Density Leaf shape/ diversity of leaf shapes

Area Total ground cover Eliminate bare ground

Area Density Time

Practical Application

Crops

• Intercropping

• Combination of fast and slow growing crops to cover the ground more quickly

• Faster growing crop varieties to make more time for GM

• Closer spacing or combination of leaf shapes

Green Manures

• Under sowing cash crops

• Increasing height of cut

• Arable silage mixtures

• Mow killed and winter killed

• Fast growing GM smother weeds and store more energy

Intercropping

Opportunities

• Increased production from smaller area spreads seed bed cultivation costs

• Better return from low gross profit/ area crops

• Shade out weeds

• Slow rainfall reduce damage improved infiltration

• Better environment for micro organisms

Problems

• Difficulty of mechanical weeding increases weeding cost

• Need markets for extra produce

• Crop rows in centre of bed too shaded

B L B L B L B L B

L L L L L L L L L L L

B L B L B L B L B

B = Brassica L = Lettuce

Path

intercrop intercrop

crop crop

crop

24 inches

12 inches

6”

24 inches

0

8

16

0 20 40 60 80

Yield gains from intercropping

Percent gain

Days between harvests

New Rotations

Rotation 1 early crops

• Potatoes

• Buckwheat/barley/lupin

• Onion/lettuce/carrots

• Persian clover sorghum

• Parsnip/beetroot

• Compost

• Broad bean/ radish

• Persian clover/barley/vetch

• Brassica/lettuce

Rotation 2

• Brassica /lettuce

• Pea /barley/crimson clover

• Leeks/carrots/ celery/celeriac

• Phacelia/crimson clover

• Runner beans/squash

• Vetch/triticale

• Pea/barley/crimson clover

Weeding

Energy Flow and Ecosystem Cycles

Linear

• Energy Flow

Cyclical

• Nitrogen Cycle

• Carbon Cycle

• Water Cycle

• Soil Nutrient Cycle

Acknowledgements: Holistic Management Allan Savory with Jody Butterfield Intercropping and the scientific basis for traditional agriculture Donald Q Innes