Believe it or not, the rains will come and the parched and lifeless landscape will again, as if by miracle, come back to green splendour. It is a cycle that has been repeated throughout time in the agricultural regions of Australia, and while it does deliver us the start of our growing season, in the process it exacts a terrible toll in terms of soil loss and land degradation.
Autumn is the period when your landscape is traditionally at its lowest ebb — after the long, hot dry. When the first rains hit bare ground, they tear the dry crust, taking away precious soil and depositing it as choking loads in swollen creeks and rivers.
Consequently, it is important to prepare for these rains. A plan that stretches production over the whole year, keeping the landscape alive even through the long, dry spells and, most importantly, making the most of every season.
In the short term
As a land manager, one of the most important guiding principles must be to use the water where it falls. Make the most of the rain, let it soak into the soil so that it replenishes subsoil moisture supplies. This is the single most important principle in land management and yet it is sadly neglected in many parts of Australia. Everything we do must be about gearing up to effectively receive and store this precious first rain.
Step One: cover the worst areas
Where possible, cover bare areas in preparation for the first rains. Concentrate on slopes where run-off will be worse and around troughs, yards and gates where erosion can be exacerbated by heavy traffic.
Rolls of good quality hay and its matted material — nothing with weeds — can be used. This will shield and feed the soil, and seeds will germinate with the rains to provide new living cover.
It is also important to place rocks, straw bales or branches on sites of erosion to slow and dissipate the water flows. Carry this out wherever you see water starting to flow, and this will stop it creating the worst and most damaging gully erosion.
Step Two: carefully open the soil up
Strategic soil earthworks are an important step to get water into the soil and stop erosion. A tractor or dozer can ‘rip’ the soil with deep steel tynes that break through the hard crust and compacted subsoil, creating the physical conditions to let water in. Ripping is used extensively in horticulture and landcare to begin the soil healing process and, when done across a slope (along the contour), it is a powerful tool.
Various soil aeration machines can also be used — turf management companies often have verti-draining or coring machines that will do a similar job. If used carefully, these machines will significantly aid water infiltration and reduce run-off and erosion.
Keep in mind that such work, particularly ripping, will create soft trenches that can be treacherous to grazing animals. Limit stock access to treated areas using fencing or concentrate ripping along boundaries and the tops of slopes where its effects will be most useful and stock movement can be easily controlled. Or, better still, use the rip lines to plant trees and shrubs.
Step Three: dealing with water repellency
As soils dry out over the hot months, they may also become water repellent — they will literally shed the incoming water, staying dry and unresponsive to the rain and even irrigation. This will greatly increase the risk of erosion and, as such, it must be dealt with.
A carefully applied application of a high quality, agricultural wetting agent can help to reduce erosion and increase water infiltration into the soil. This is effective if it can be applied as a liquid or as granules, then thoroughly wetted into the soil.
Other products such as seaweed and fish emulsions are also good and, in most cases, bulk supplies of such products can be purchased or made. Composted manures are also good to spread into the soil.
Step Four: sowing cover
Sowing a cover crop, or ‘green manure’ crop, with fast-growing plants like oats, lupins, vetch, barley and clovers is an important strategy. Such plantings grow quickly with the first rains, meaning the young roots and shoots of the new plants can protect, bind and hold the soil. Such a crop can also help to shade out weeds such as Paterson’s Curse.
If you have access to grass runners such as kikuyu, they can be incorporated in suitable eroded areas in the lead up to the rains. If you give them a good bedding of manure or compost and some irrigation to get them started, they will take off with the first rains and quickly cover precious soil.
Step Five: never leave the soil bare
This may be cold comfort for this year, but always aim to keep cover on the landscape, particularly over the long, dry period. Any cover is better than none, and as a general rule, you should aim for at least 75 per cent cover on the soil — even if it is only dead weeds.
The trick is to reduce grazing before this critical level is reached, resting or spelling such areas as needed. This may be hard but if you want to have good soil, paddocks and pasture, then there is no other way — you will need to find alternatives to putting animals in vulnerable areas. Destocking, supplementary feeding, use of walk-in/out yards and irrigation of small pasture areas closer to the homestead can protect vulnerable areas from devastating grazing pressure.
In the long term
A bare paddock is a liability visually, environmentally and economically, and it will take time to heal. Set out below are some of key steps to permanently deal with the ‘dust bowl’ syndrome, once and for all.
Step One: improve your soil
Get a soil test done and make the changes required. This is a simple and important part of transforming your landscape, but it is overlooked in many cases. A range of soil conditioners such as lime, gypsum and dolomite may be required. If used consistently, they will bring the soil back to life, improving its structure and making it more receptive to the precious rainfall and subsequent plant growth.
There are several companies coming up with excellent fertilisers and soil conditioners that can make a difference — check out Stocktech Australia and Baileys Fertiliser.
Step Two: reduce weeds and establish perennials
Aim to have as many perennial plants in your landscape as possible. Only these long-lived plants can truly hold your landscape together and stretch your production, regardless of season or weather extremes.
Where possible, use deep-rooted, drought-tolerant grasses that will hold the soil together and hopefully shift out weeds. When they are well-managed with a fertiliser program and rotational grazing, they will have a good hold on the soil through the grip of a drought and will spring back to life when the rains come.
These pastures should be flanked and bordered by deep-rooted fodder hedges and shelterbelt trees and shrubs. Check with the Department of Agriculture and Food or local Landcare Centre for suitable local species. Ideally, these plantings should go across the slope and along the contour, and they will be of enormous benefit to stop erosion.
So while a bare paddock is a landscape liability, if you aim to use the water where it falls and keep it on the slope and in the soil, you will be able to transform a devastating loss into production potential. Good luck and happy planting.
''This is an extract from Chris Ferreira’s up and coming book, ‘Heavenly Hectares — a guide to creating a beautiful, productive and sustainable landscape’. Follow Chris on www.landcaresolutions.net.au
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