Designing water into landscape earthworks course Goulburn, April 2008

Transcription

1 Designing water into landscape earthworks course Goulburn, April 2008 Presented by Summary presentation to Permaculture Sydney West by Jonathan and Sue Cook, 5 May 2008 Taught by Geoff Lawton and Darren Doherty Site assessment Water resource identification Dam types, their strengths and weaknesses Water harvesting systems, swales, checkdams and gabeons Earthmoving equipment - bulldozers, scrapers, excavators Keyline Design Carbon sequestration Cost effective soil creation Composting and compost teas Water harvesting & reticulation Designing water into a property Dam placement Pasture improvement Holistic Management

2 Historic Goulburn Australia s first inland city

3 The South Hill property on the outskirts of Goulburn

4 The South Hill property 100 acres on the outskirts of Goulburn

5 The main house at South Hill

6 Typical country around South Hill

7 Presentations by Geoff Lawton in the main house

8 Darren Doherty presenting

9 Impromptu what do I do with my property sessions with Geoff and Darren

10 The scale of permanence 1. Climate 2. Land shape 3. Water 4. Roads 5. Trees 6. Buildings 7. Subdivision 8. Soil

11 Design for water first Saddle between the two hills ideal place to end a swale and site a saddle dam

12 Swales are level contour trenches Swales Catch runoff water and hold it so that it infiltrates into and hydrates the land downhill Excess run-off usually directed into a dam Can also serves a spillway for the dam Banks of the swale planted with trees (food crops, bush-tucker, cattle fodder)

13 Mini drainage diversion swale at Illabunda Series of swales planted with tree crops Image courtesy of Darren Doherty and Permaculture.biz Typical swale cross-section

14

15

16

17 Pegging the swale using a dumpy level and a laser level

18 Location of the swale at South Hill about 300m long 3m wide with a catchment of about 3 Ha 3 Ha catchment with 500mm rainfall pa gives 15ML of water per year!

19 Bulldozer ripping the ground prior to digging the swale

20 Digging the swale (D5 bulldozer 27 tonnes)

21 Digging the spillway area by backhoe Digging by hand at Illabunda! (the water shows the level)

22 Late afternoon view of the Mulwaree River

23 Checking the swale bottom is level Using the dumpy level as the sun set

24 Sunset on Saturday

25 The completed swale (earthworks) and winter arrives!

26 Evening field lecture in the swale a very cold Sunday night

27 Carbon sequestration and improving the fertility of the soil with compost tea soil is an animal that is all mouth and fungi are the teeth GL Good topsoil is ~8% organic matter PA Yeomans 1.6% increase in organic matter in topsoil on 12% of the earth s surface would reduce atmospheric CO 2 levels by 100ppm (ie to pre 20 th century levels) and solve the global warming crisis CO 2 sequestration performance Trees 200 tonnes/hectare after 15 years (photosynthesis) Soil 57 tonnes/hectare after 1 year (855 tonnes by 15 years and cheap as chips)

28 Soil CO 2 sequestration process GT CO 2 year lost to the atmosphere 110 GT per year CO 2 absorbed by plants by photosynthesis 50 GT per year CO 2 lost to the atmosphere by oxidisation Carbon oxidises (combines with oxygen to form CO 2 ) Accelerated by poor management of the soil (poor ploughing, overgrazing, erosion) 60 GT carbon enters the soil Some becomes Soil Organic Matter (SOM) and is sequestrated

29 Carbon sequestration and improving the fertility of the soil THE SIMPLE SOLUTION: Put the carbon back in the earth where it belongs. Degraded soils can store up to 5 times more organic carbon in their surface layers than they currently hold if the soil management approach changes. Through the application of these types of management methods, Soil Carbon Australia can make an impact on global warming. THE NATURAL SOLUTION: Carbon is naturally sequested in topsoil via biological processes surrounding actively growing roots of pasture grasses and cereals. Encouraging these processes is cheap, efficient, and ecologically beneficial. THE ACHIEVABLE SOLUTION: Soil carbon levels can be increased by adopting forms of carbon farming, including time-controlled grazing management, pasture cropping and biologically beneficial farming practices (such as using oxygenated compost teas and Yeomans ploughing - jc) Soil Carbon Australia P/L (Bond University Qld)

30 Compost and compost tea Compost tea is very effective at increasing micro-organic life in the soil on all scales from the backyard to broad-acre farms

31 Berkeley method of fast (18 day) compost Advantages of fast composting: Finished compost in a few weeks Higher nutrient content due to less leaching of nutrients Fewer viable weeds and weed seeds Disadvantages of fast composting: Additional effort required Large amounts of compost material required at once

32 Getting the balance right Need the right nitrogen / carbon balance so that the material breaks down as quickly as possible and the right sort of bacteria grow. Bacteria and fungi need carbon for energy, nitrogen for protein synthesis Aim for :1 carbon / nitrogen balance Typical materials: Urine 1:1 Fish 7:1 Chook poo 12:1 Cow poo 18:1 Horse poo 20:1 Green weeds 30:1 Dry hay 150:1 Sawdust 500:1

33 Need at least 50 0 C ( is optimum) inside the compost heap for the compost to form rapidly and to kill the weed seeds Aim for at least 1m 3 compost heap (1m x 1m x 1m) Day 1 1/3 manure 2/3 shredded carbon materials Mix into single heap (can also layer - easier) Soak with water Cover to keep excess rain off (jute is good, allows breathing)

34 Compost activators to move things along anything which has lived can live again Dead fish Dead cat Urine Old compost Comfrey Yarrow Nettles Place activator in the middle of the heap

35 Day 4 Turn the heap over by moving sideways. Inside to outside Pitchfork should take about 20 minutes

36 Day 6 Turn over Squeeze test should only drip once (if too wet ventillate with chimney) Day 8 Turn over Test temperature should be o C Turn every second day until about day 18 By day 18 it should be ready - dark brown, fine, earthy smell If not ready go another few days After day its development plateaus. Stable life state.

37 Problems Not hot enough Heap not large enough Heap not wet enough Not enough nitrogen - (can add a few drops of blood and bone to each pitchfork turn) Volume drops or white fungus (fire Blight) too much nitrogen (add carbon) A small amount of fire blight OK as it is an edge indicator

38 Shredding the more woody material with a mower at Illabunda Adding horse poo, comfrey and garden greens Cover the finished heap (12 April 2008) 3 May weeks later

39 Oxygenated Compost Tea Made by mixing small amount of good compost with water and aerating The aerating process blows the micro organisms off the compost and into the water where they reproduce rapidly Requires small volumes of compost a handful of compost in 120 litre of water will service 1 Hectare of land Requires a lot of air - 1 litre air per minute per litre of water Brew for 24 hours Dispense within 6 hours of aeration (as the organisms die after this) Dilute 50:50 water Use low pressure pump or dribble (so not kill the organisms) Apply to ploughed furrows, with seedlings (or onto the ground or onto folliage) The micro-organisms can live up to 17 years in the ground

40 Compost Tea Brewers GeoTea 1,000 litre and 20 litre BioActive Microbrewer 24 hour compost tea brewers by Australia Soil Additives and Products (ASAP) - Elaine Ingham

41 Everyone loves a good plough! The Yeomans plough an essential tool for restoring fertility to the soil on broad acres

42 The deep and narrow cut of the plough aerates and allows water to penetrate into the soil (without turning over the soil and accelerating oxidisation) The special tine on the Yeomans plough In 1 year with Keyline ploughing with compost tea and then planting From no topsoil to 300mm From 2% to 8% organic matter

43 Keyline Ploughing

44 References and links