04. Magic Dirt
The best dryland cropping country on The Black Soil Darling Downs Q. is now worth $8000 per acre – which is up to 2- 4 times more than lighter country with a similar annual rainfall of 650 mm. You can buy grazing country on the Western Fall of The Great Divide in Qld for $1000 to $3000 per acre as of Dec 2021.
These valuable tracts of cropping land all have the “highest soil water holding capacity” of any land in Australia. So, a handy farmer may almost certainly harvest a Winter crop of wheat (planted in June) by the end of October – even in the driest years – if you start with a “full moisture profile” * in Autumn.
Pure sand has the lowest water holding capacity – however – some mineral rich sandy soil – can – with good Winter rains – perform on par with the black self-mulching soils of The Downs – due to the cool season moisture holding advantage. Interesting thing about lighter cropping and grazing country – is that it responds faster to rain – then it dries out faster.
It is the massive surface area of silt and clay particles that holds more water for longer in the heavier soils.
With lighter soils you can delve clay subsoil back to topsoil. You can also add vegetative matter and animal offal to increase gels in the soil. Shade and reflected light are another moisture conservation strategy.
You can also pick your location to conserve moisture – altitude and latitude are significant influences. Stocking rates on good country down around The Grampians in Victoria is upwards of 5-fold better than similar rainfall country in Qld.
Make Dirt Magic
The best grassland grazing managers all rely upon one fundamental management strategy: keep the soil covered with a standing body of pasture and use grazers to trample and grind the pasture – always leaving a cover of mulch and some standing pasture – then allow the pasture to fully recover before grazing again. Over time – pastures develop deeper roots – and store more water and energy for faster and thicker pasture growth. Verses the opposite which is known as the Law of Diminishing Grasslands. So – when it stops raining – you need to reduce stocking rates – to maintain covered ground – or waste time when it does rain again – restoring pastures back to abundance – and maybe lose money on fodder – devalued stock – or even dead stock.
PHOTO 1: Black Soil South of Jimbour – Darling Downs. The thin blue line on the horizon is Watershed of The Bunya Mountaion – Part of The Great Divide – about 40 km away.. This black soil country is part of an alluvial flood plain that is 150 km long and up to 100 km wide in parts. Flood waters from here ultimately end up in South Australia. Clods are from the first working with a disc plough after a cotton crop harvested May. There is a move away from complete no-till by some farmers to occasional till or minimal till. Most noticeable in this cropping country are the almost non-existent fences. Animals are no longer part of cropping – instead they have been replaced by chemicals and synthetic fertilisers produced with electricity. However the tide is turning – some progressive farmers are now researching and developing plant and grazing animal farming systems. Which requires a return of fencing. DATE of PHOTO: 25/11/19
Full Moisture Profile*
When soil moisture is depleted on dryland cropping country – you need 200mm plus of rain over a few weeks to restore a full moisture profile to a depth of one metre. Modern dryland cropping management relies upon deep subsoil stores of moisture. Occasionally a bold farmer will dry sow seed – then the farmer waits in hope for rain. So today – there are Bold Farmers – and there are Old Farmers – but there are no Old Bold Farmers.
Dryland Cropping
Refers to any crop grown with rainfall only. In 600-700mm rainfall zones around Australia – these crops include Wheat Barley – Oats – Millet – Sorghum – Corn – Chick Peas – Fava Beans – Daikon Radish – Mustard – Butterfly Pea – Clover – Cotton. Go 800 km West of Brisbane and irrigators use 1000mm* of irrigated water from the Warrego River to grow cotton in a 350mm rainfall zone. *10 megalitres per hectare viz: 10,000,000 litres of water. Some irrigated tree crops in the NT use 15 megalitres per hectare.
Photosynthesis puts organic carbon and nitrogen in the soil. Increase your dirts’ water holding capacity by increasing photosynthesis
Provided you have the moisture – you can rely upon constant plant growth – verses bare fallow ground – to increase your soils water holding capacity. Bare exposed earth is in a state of constant decline as both carbon and nitrogen escape back into the atmosphere. To reverse this natural process – you need the right plant species at the right moment in time. It is then a balancing act between available moisture – plant growth – animal interactions and movements. Managing Constant Growth to Increase Production is the Foundation Management Key for Living Fallows – Fully Described in Ground Workers for Garden Food PDF SERIES
Ground Workers for Magic Dirt Seed Kits
Perfect Seasonal Combinations of Plants to Make Your Own Magic Dirt.
GO TO: Ground Workers for Garden Food Crops PDF Series
A simple template for productive gardening based on using a few plants to: (1) grow your own garden mulch. (2) smother undesired grasses and groundcovers. (3) then to be cut and rolled to form humus rich garden beds.
PHOTO 2: Standing sorghum stubble after a May harvest. Stubble is sometimes left standing – or it may be slashed and shredded as mulch – or ploughed in. Weeds are controlled with an arsenal of chemicals. Some have a 12 month residual effect – so when applied as a liquid to the soils surface – grasses will not germinate for up to 12 months – but selected crops can depending on the type of chemical. Other chemicals may be used to defoliate the plant before harvest if its leaves are still green Then chemicals may be added to stored grain to kill weevils. DATE of PHOTO 25/11/19.