• the extent of the stubble load from last year’s crop,
• the type of the crop,
• soil conditions,
• weed and fertiliser management,
• seasonal conditions.

Each of these factors will change from year to year, so different conditions call for different management strategies.

Stubble retention in a cropping system offers the potential to increase microbial activity, improve soil stability and structure, retain soil moisture and increase soil carbon levels. But unless your stubble is handled correctly, the advantages available from retaining stubble can easily be lost.

A new tool to add to your management arsenal can make your decisions easier.

Trashcutter^®: A breakthrough in stubble management

The K-Line Trashcutter^® is a new machine that has been developed by K-Line Agriculture, working extensively with agronomists and farmers to develop a better system for stubble management.

Traditional mulching leaves stubble lying on the surface of the ground, making the soil prone to wind erosion, especially in lighter soils. The Trashcutter^® allows the stubble crown to remain in the soil as an ‘anchor’, minimising wind and water erosion. This is achieved by the advanced design of the Trashcutter® which lays the stubble to one side and then slices the stubble with self-sharpening discs into short lengths.

Stubble and residue is left evenly spread over the ground surface, making the work of trash flow through the seed drill so much more efficient. ‘Hair-pinning’ is minimised with the Trashcutter^®.

How the Trashcutter^® system works

A unique feature of the Trashcutter^® is its adjustable disc angle and down pressure, which can be altered to take into account the state of the stubble and soil conditions.

With the Trashcutter^®, you now have complete control over how much soil disturbance is needed, for example in zero-till operations; how finely the stubble is cut; and how much tillage may be needed for chemical incorporation and light weed control.

The beauty of the machine is that you have complete control of the operation via the adjustable disc angle and on-the-run adjustment of the down pressure of the machine, which controls the cutting action.

The Trashcutter^® operates in a fast and efficient manner, at low horsepower, evenly distributing trash, which makes control of seeding depth and placement so much easier. Added features are its ability to handle rough and undulating ground and its narrow transport width.

Crop residue can act as a physical barrier to wind and water erosion. Residue is most effective when it is both lying on the soil surface and anchored to the ground. The more stubble can be retained, the more soil moisture can be conserved and less lost to evaporation over summer. Wind and water erosion can be minimised and soil microbial activity, in time, can be increased, as can soil carbon capture.

Managing stubble is a key feature of conservation farming. And the critical element of effective management is an ability to adjust to the variety of factors thrown up by different seasonal conditions. Having a machine as adaptable and efficient as the K-Line Ag Trashcutter^® has made the job of managing stubble a whole lot easier.

Among the range of K-Line Ag machines that you may see at one of these venues are the Speedtiller ^®, Flexi-Mulch ^®, LightningRipper ^®, ThunderRipper ^® & MaxxRipper ^®. It’s a great chance to examine every feature of the machines, talk to the dealer at the machinery stand and discuss the features of these implements with your friends without any sales pressure whatsoever.

As you can see from the list below, K-Line Ag will be represented across the length and breadth of the country – a fair indication of the suitability of their machinery to the wide range of agricultural conditions and farming systems in Australia.

There’s an event near you

Attendance at agricultural field days has never been higher – Tocal’s Field Days set a new record! Farmers are obviously taking the opportunity of these displays to compare and contrast a wide range of agricultural machinery, and the dealers are only too happy to show off their wares and chat with even the casual observer.

These events are always held in an informal and festive atmosphere, where friends and colleagues meet for a great day out, and also to take advantage of the great deals on offer at these special events.

The future is in your hands

There are huge benefits to conservation farming, not least being less soil erosion, better soil structure, increased soil carbon and a build-up of beneficial soil microbes. Reduced tillage leads to great savings in machinery costs and time, but a greater reliance on chemical control of weeds.

Over time, weed resistance to common herbicides will arise, and some type of tillage is required to break the cycle of weed growth and seed-set. This is where a tillage implement like the K-Line Ag Speedtiller^® can play a role. This is a classic example of a machine built specifically for Australian conditions. An added benefit of the use of the Speedtiller^® is its ability to incorporate lime into an acidic soil where mixing into the topsoil is essential for successful growth of pH-sensitive seedlings. Lime can be very slow acting, and a poor investment unless it is incorporated.

The use of tillage in conservation cropping must be strategic. In the southern cropping regions of Australia, tillage should be left as late as possible to conserve soil moisture and minimise the risk of erosion. In the northern cropping zones, where both winter and summer cropping is common, the timing of tillage is important to take account of the risk of storms and the storage of soil water. It has been demonstrated that a one-off pass with tillage machines such as the K-Line Ag Speedtiller^® will do little damage to soil aggregates and infiltration rates.

The benefits of tillage in conservation farming

Research over many years has proven the strategic tillage such as experience with the K-Line Ag Speedtiller^® in a conservation farming system can have the following benefits:

• Agricultural lime, which has poor solubility, can be incorporated to improve its effectiveness.
• Levelling of the soil surface for small seeded crops with offset discs followed by the roller toolbar on the Speedtiller® achieves the ideal seedbed in one pass.
• Compaction of the soil surface by grazing animals or controlled traffic lanes can be effectively reduced by cultivation.
• Plant disease cycles can be disrupted by occasional stubble incorporation. Disease build-up such as Crown rot, Rhizoctonia and Yellow spot in wheat will be broken; Blight in chickpeas and Fusarium disease in sorghum are all minimised and reduced by breaking up stubble and incorporating it.
• Crop pests such as cotton bollworm or corn earworm (Helicoverpa spp.) larvae populations will be reduced, as will snail and slug populations.
• Rodent populations, especially mice, can be partially controlled by breaking up their stubble cover habitat, disrupting their burrows and burying their food sources. In mice plagues such as being experienced in the current cropping season, incorporating stubble by cultivation will help, but obviously not eliminate, plague populations of these rodents.
• Herbicide resistance can be partly overcome and delayed by eliminating growing weed plants and burying new weed seeds such as annual ryegrass.

Are there downsides to strategic tillage

In theory, “clean” seedbeds using tillage machinery such as the K-Line Ag Speedtiller^® to incorporate stubble and weeds appears contrary to the principles of conservation farming. But the benefits of strategic cultivation far outweigh the disadvantages. The key word here is “strategic”. Cultivation becomes an important tool in a holistic management approach.

Of concern to farmers who aim at a sustainable cropping regime is the conservation or sequestration of soil carbon. Again, recent research has addressed this issue and found that “it is likely that a single strategic tillage event implemented occasionally would have limited impact on stores of soil C”^[1]. The amount of carbon loss from soil due to tillage depends more on other factors such as soil moisture and temperature, fertiliser inputs, stubble management and the type of crop and pasture rotation practised.

Another important aim of conservation cropping is to preserve and encourage beneficial soil organisms (both the microflora and fauna). Soil fungi filaments and beneficial bacteria are essential in releasing soil nutrients and assisting their uptake by plants. Any tillage disrupts their lifecycles and reduces their populations. These effects can be minimised by adopting a judicious and occasional, strategic use of tillage. The recovery of soil organisms is more likely to be swift if soil moisture and temperature levels are favourable.

What about soil structure and the risk of erosion? There is no doubt that soil aggregates are disrupted by tillage, but again, research indicates that this causes little or no damage to overall soil physical properties. In no-till farming where a single tillage is carried out, recovery time takes from zero to a maximum of four years, and there appears to be little effect on grain yield from this type of tillage regime. A one-pass treatment using the K-Line Ag Speedtiller^® at the right time, with the right soil moisture will have minimal impact on soil structure and soil erosion. And the impact of tillage on soil moisture reserves at sowing time depends very much on the rainfall and temperatures (evaporation) between tillage and sowing. Obviously the frequency and intensity of rainfall after tillage is beyond the control of farmers.

Strategic tillage is one important tool in the conservation farmer’s arsenal. It fits neatly into an integrated weed management program. Its main benefits are to overcome herbicide resistance in weeds and reduce the weed seed burden, and where needed, to break the cycle of crop pests and diseases. A one-pass treatment with specialised machinery such as the K-Line Ag Speedtiller^® brings these advantages together, giving flexibility to a cropping program. Strategic cultivation can minimise the time soil is exposed and the Speedtiller^® brings the added benefit of being able to incorporate lime to remedy a soil pH problem.

[1]

While it does occur naturally, soil acidity is also an unavoidable side-effect of agriculture, which increases the concentration of hydrogen ions in your soil. On the surface, it may seem like a trivial issue, but left unchecked it can cause lasting problems for your crops.

Careful management of soil acidity can save you a lot of money in the short- and medium-term. The trick is to find the right balance between lime application and tillage. But before we get to solutions, let’s take a deeper look at the problem…

Getting the balance right

For decades, soil acidity has had a big impact on crop production in Australia, especially on sandy soils. Low soil pH reduces nutrients for plant growth and increases aluminium content, which is toxic and can badly stunt root growth. Barley, Lucerne, Canola and Medic are particularly sensitive to soil acidity; as are most pulses, including lentils, chickpeas and fava beans.

Soil acidity builds up slowly over time, so it’s easy to think it’s not costing you much and that it’s only an issue in the topsoil, where it’s easily treated by applying lime on the surface. But the fact is, acidity can seep into the subsoil too. So how do we know when that’s happened? And how do we balance our urgent need to farm, with the pressing need to treat the acidity issue?

The acid test

Surface and subsurface acidification may show up as uneven crop and pasture growth, yellowing of crops, poor nodulation and stunted root growth — but these signs of surface and subsurface acidity aren’t easy to spot.

To be safe, you should monitor your pH levels with regular soil testing at least every five years. Samples should be taken from the same soil type and land use, with at least 20-30 from both the topsoil and the subsoil. When the soil pH (CaCl2) falls below 5.0, it’s time for a lime solution.

But lime will generally only seep into the subsoil when the topsoil pH is kept above 5.5, otherwise all the lime is used up neutralising the surface acidity. So a good solution is to also till deep into the subsoil, working the lime into it without waiting for seepage to occur.

The THUNDERRIPPER® with Hydraulic Tines by K-Line Ag is built to shatter compacted soils. With tines that reach deep into hard pans to break and lift them up, this heavy duty Ripper ameliorates the soil by ripping through hard pans. This increases yields through:

• greater root development and plant growth,
• improved nutrient update and moisture entry, and
• organic material incorporation

K-Line has a range of Rippers suitable for all farming types and soil conditions.