Accelerating Change hosted the third Successful Summer Cropping workshop in Barooga on the 28th March to round off the summer cropping season by talking through harvesting practices to optimise silage quality. The group also began the first part of the Successful Winter Cropping series, discussing how they would set up their winter cropping agronomy program, and covered the key requirements to set high yield potential for forage crops from the start.
The following take home messages were highlighted by presenters David Lewis of Lallemand and Matt Nihill of Landmark Elmore that are of particular importance this season. More information can be found in the full presentations under our Cropping Resources tab.
Corn silage harvest management
Many farmers have got their basic silage management processes down pat. However to drive efficiencies and optimise nutritive outcomes there are a number of strategies that can be implemented to get that extra return on investment. David Lewis took the group through new harvest processes and monitoring and measurement strategies that can take your product to the next level.
Shredlage®-what is it and why?
Shredlage® is a patented and branded harvesting process that produces long chopped highly processed silage. It requires harvesters that can cut longer cut corn, 26-30mm theoretical length of chop. The Shredlage type kernel processer rips stalks length ways into planks and strings as well as effectively processing corn kernels. Improving the processing of the kernel and stover helps improve packing and increase exposure of the plant fibre to microbial activity. Improving processing and increasing effective fibre creates opportunity to modify PMR and TMR feeding practices and can potentially reduce the amount of additional fibre sources fed with corn silage, such as straw and hay.
Longer cut silage usually has a negative impact on compaction of the stack, but if the cut technique is right, Shredlage® and other similar processing equipment should increase cut length without compromising on silage fermentation quality, stack density and compaction as well as reduce sorting of feed on the bunk by the cows. This is because the stalk is shredded, not just chopped at a longer length.
When should I use it?
The Shredlage® process and long chopped highly processed corn silage has been used in Australia for a number of seasons. Lessons learnt so far are the need to stay focused on silage quality and fermentation above the pursuit of Shredlage® or long cut corn silage if crop conditions don’t allow. This means that harvest processes have to be flexible to work towards those outcomes. If moisture range of the crop is too low, longer cut silage will still have difficulty compacting appropriately, even if it is shredded appropriately. In these cases, long cut length may have to be shortened in order to achieve optimum compaction and fermentation.
Harvest planning & timing
Regardless of type of harvesting equipment used, timing of harvest as well as effectiveness of processing is critical to achieving high quality silage. Many issues that can crop up at harvest time should be addressed in the weeks leading up to it and cannot always be solved at harvest time. Pre-harvest dry matter testing will assist you to avoid a stab in the dark when it comes to scheduling harvest, particularly around unexpected challenges like rain events. From David’s experience, dry matters are mostly always drier than what you would expect and people often miss optimal timing. This is even critical with Shredlage® and long cut corn silage as if you wait to long for harvest you may have to sacrifice the benefits from increased chop length to optimise compaction and fermentation.
Monitoring & measuring to help you improve harvest management
Once dry matters are assessed and harvest begins there are a number of measures you can use to provide immediate feedback on the effectiveness of processing and whether any parameters need to be adjusted to improve the final product. Processing effectiveness is just as important as harvest timing in maize silage. Cows will not be able to digest whole grains, and grains account for 65% of the energy and 46% of the dry matter in the silage. When feed tests are conducted, the sample is ground up and then tested. So nutritive results of feed tests will not necessarily reflect nutrition available to the cow if kernels are not processed adequately. It is critical to undertake visual inspections as well as feed tests to determine quality. Kernels must be less than ½ size in order to be deemed effectively processed.
Damaged but not fully cut kernels are not effectively processed. Monitoring of the processing of the plant stem is also important during harvest. Improved processing of the stem allows for better digestion by rumen bacteria as well as better packing density of the stack. During harvest, monitoring of kernel and stem processing using a consistent method will allow you to make adjustments to processing if required.
Creating a good stack
Increasing your monitoring of the stack as your build it will also allow you adjust processing if required to achieve optimum density of the stack.
If packing density needs to be increased try:
a shorter length of cut,
add more packing tractors,
increase tractor weight,
reduce layer thickness or
slow harvest rate.
Improving record keeping of what is going into the stack can also assist you to optimise how it is used at the other end. Keeping a diagram or some form of visual record of where everything is in the stack will assist you to know exactly what is coming out of the stack when, and what rations may have to be adjusted to compensate for differences in quality.
Agronomist, Matt Nihill from Landmark Elmore took the group through how to set up your winter cereal program for success from the start, and highlighted some key management issues that are popping up this season.
Lessons from last year-eliminate top soil issues before you start
Analysis of how last year’s winter crops and pasture performed will assist diagnosis of factors that could affect the success of this year’s cereals. Appropriate drainage is a must for high yielding crops. Wet conditions last year may have highlighted areas that could benefit from improved drainage from installation of spinner cuts to improve drainage. Click here for more information on how to do an effective spinner cut.
NDVI imagery throughout the season can show plant stress not easily identified through the naked eye. This can highlight areas that need investigating for production constraints like drainage. A collection over NDVI images over a few seasons can help demonstrate how management practices are addressing areas of poor production.
Note: NDVI imagery shows relative crop stress and must be groundtruthed in crop through analysis like soil and tissue testing and visual inspections. For more information about how NDVI works visit GRDC.
Another key point for preparation for winter cereals is irrigation strategy. Watering up was discussed by the group. Watering up is usually dangerous for cereals unless soil is warm and dry to start with it. If you do try this, to optimise success make sure:
The seed has good vigour. Ask your agronomist or seed rep to organise a test.
Get the water on and off quick
Be as confident as you can there will be no rain for 7-14 days after irrigation
Select a site not prone to weeds
Don’t do it after the 1st April (too high risk of rainfall and low soil temps)
The group also asked some questions on picking the optimal seeding rate for winter cereals. Appropriate seeding rate is a mixture of target yield, seed germination rates, variety and sowing times. Higher seeding rates don’t necessarily lead to high yields. Higher seeding rates can also increase the rate of lodging as plants are more shaded causing stem elongation between internodes.
Weed Control is an important consideration this year after last year’s went winter and spring hampered ongoing weed management strategies. History is the biggest indicator of what weeds you will have to deal with so when selecting paddocks and planning rotations keep a record of what weeds were problematic last year. Crop selection and rotations will determine what post emergent chemical weed control options are available to you. Using selective herbicides:
Most broadleaf weeds (e.g. bindweed) can be controlled in a cereal
Most grass weeds can be controlled in a pulse e.g. vetch, clover.
Keep in the mind the end game for your cereal crop. If you are using it to prepare for spring sown lucerne, use the cereal rotation to maximise broad leaf weed control because there will be limited post emergent weed control options if broad leafs are still a problem when lucerne is planted.
This year it might be tempting to cut back on knockdown applications if there are only a few weeds appearing and cashflow is tight. However be mindful if there are a few weeds now there could be huge numbers in a couple of months’ time. When using glyphosate as the knockdown, adding sulphate of ammonia improves water quality, the uptake of glyphosate by the plant as well as compatibility of herbicides in the tank.
Should I use a pre-emergent?
The group discussed how to use pre-emergents effectively. Pre-emergents kill weeds at or shortly after emergence. The placement of the pre-emergent is critical for success and also to avoid damage of the crop. The majority of pre-emergents are taken up the roots of plants, so the chemical needs to be placed below the weed seed in order for the weed’s roots to access it. If the band is above the weed seed, the weed can potentially grow through it undamaged. On the other hand, the target crop needs to be sown below the pre-emergent band so it can grow up through it safely. Moisture availability is also important-some pre-emergents need a certain level of moisture to activate them.
Regardless of the chemical weed control program, there are a few cultural weed management tips that can implement to get on top of weeds:
Sow when the soil is still warm
Narrower row spacings will ensure quick ground cover
Sow East West where possible-stops light from reaching the ground quicker.
Sow cleaner paddocks first.
This year it is important to be extra vigilant about Russian Wheat Aphid. It is a significant new pest in Australia. It is not currently present in our region but thrives when there is a green haven over summer.
Look out for:
White and purple longitudinal streaks
Reduced photosynthetic activity
Insecticide seed dressings will help avoid infestation and good populations of beneficial will also assist such as lady birds, lacewings and fungi. BE AWARE that insecticide seed dressing grazing withholding periods. Gaucho, for example, is 9 weeks WHP.
Nitrogen considerations from 2016
Last year’s wet conditions meant that spring 2016 was a high year for mineralisation. High yields also meant high nutrient removal, so N losses from both of those processes are likely to be significant. This year it is important to watch N levels, as there may be low pools of mineral N to draw from. This also applies to crops sown into last year’s pulse crops as they may have not fixed much N. In addition, in any season it is important not to overestimate the N benefit of a pulse rotation for the following crop if it is made into hay or silage. Approximately two thirds of N is removed at harvest time.
One way of determining if N is a limiting factor during the season in cereals is to try an “N rich strip”. At sowing, do a double strip of N application of 50-100 units of N. As the season progresses, compare the difference in performance between the N rich strip and neighbouring parts of the crop, which will help indicate if N is a limiting factor in crop development.
Choosing a wheat variety
The group were given a quick reminder on the difference between spring and winter wheat varieties. Winter wheats are varieties like wedgetail. These cultivars require vernalisation (a cold period) to run up to head. These can be sown early as they won’t switch from vegetative growth to reproductive phase until their cold requirements have been met. They will have a longer vegetative period for grazing.
In contrast, spring wheats require heat units (daylight and warm temperatures) in order to switch into reproductive phase. They traditionally have a shorter period of vegetative growth which means a smaller period for grazing. Interestingly, last season we had instances where long season spring wheats headed later than some winter wheat varieties because the heat unit requirements were met so late in the season due to the cold spring.