Accelerating Change held part 2 of the Successful Winter Cropping program in Echuca in August. Farmers and agronomists came together to hear about key agronomic management issues and opportunities occurring this season in winter cereals. The day also covered management decisions to optimise quality of winter cereal silage. Farmers Andrew & Christine Sebire spoke about how they integrate winter cereals into their dairy feedbase, and how it was performing in 2017. Agronomist Luke Nagle covered off on how agronomic management was progressing, what to look out for now and what we can expect as the rest of the season plays out. Silage consultant David Lewis spoke about the importance of planning from the start to reach your silage goals, and making good in-season decisions to maximise your return on investment and quality of end product.
The day covered some excellent technical information to assist farmers you can find here:
Luke works with many dairy and cropping clients in the Murray region and has seen a number of challenges and opportunities in winter cereal agronomy this year. He went through a full calendar of agronomy for winter cereals, detailing key management decisions that take place over the season and how to approach them, including how to manage grazing. Here is the summary:
Ensiling whole crop cereal silage
David has vast experience working with dairy and intensive beef farmers to ensure winter cereal silage in the pit is the highest quality possible, often through difficult seasonal conditions. David shared his top management considerations that farmers and consultants need to be on top of if they are going to the get the best return on investment from their crop.
Timing of Harvest
David spoke out the importance of planning for timing of harvest right from the beginning. Being really clear on what product you are trying to achieve and how this fits into your feeding system before you put anything in the ground is critical to ensure you get what you want at the end. There is a compromise between feed quality and yield, and protein and starch, so knowing what you need in your feed budget will ensure you can utilise the end product most effectively. David reiterated what Luke also outlined in terms of selecting a species and variety that is going to fit your end goal. Think about where end goal for the crop, how much growing season you expect to have, and select early, mid or late cultivars accordingly.
Whole crop cereal silage can be cut at 2 stages of growth:
1. Flag leaf-Boot stage (lower yield, generally higher ME & CP)
2. Late milk-soft dough stage (higher yield, high starch, variable ME, lower CP).
Timing of harvest needs to be matched to which of these silage products you are trying to achieve, what seasonal conditions are like and actual development stage of the crop. Worst case scenario is if both windows are missed and crops are cut somewhere in the middle. This can lead to a compromise on yield as well as quality.
Once target growth stage has been selected, each silage type has slightly different management required.
Flag leaf-Boot stage silage needs to be wilted similar to pasture silage. Dry matter targets should be around 33-40 % for a stack or pit. This can be difficult as this growth stage is early in the season. Big wide fluffy windrows can assist to achieve the right level of wilting. Silage additives are essential if crop is not wilted enough. Late milk-soft dough silage on the other hand, can be directly cut without wilting as it can, pending seasonal conditions, dry to an appropriate level standing. Dry matter should be around 36-42 %. Direct cutting can be advantageous particular if it is dry, to reduce dust, and if cereals have been sown into cloddy paddocks.
Responding to seasonal conditions
Even if you have clearly defined goals from the start, harvest timing doesn’t always go to plan. Particularly in northern environments, harsh climatic conditions can mean crops run out of moisture quicker than planned. As the season progresses, keep checking back and considering crop development. Can you still achieve your goal? If you are aiming for late milk silage will the crop make it? Assess and manage accordingly.
David spoke about the need to go out in the paddock and proactively monitor dry matter of the crop. In our environment, moisture content can change very rapidly, particularly if there is a run of hot north westerly wind. As cereal crops run out of soil moisture they begin to draw moisture from the bottom of the plant to fill the head. To check moisture content, break open the stems of mature crops. They can be hollow and dry, even if the crop still looks green from above.
In particularly dry years, parched grains won’t soften and are hard to process as the soft sugars are all converted to starch. It is particularly important to time harvest of wheat and barley to avoid this, and not go in too late. This window can close very rapidly, within 7 days for barley. In dry years you may need to strike a balance between whole plant moisture and grain filling.
Pack & seal immediately!
Whole crop silage expands very quickly, much more so than pasture. This is because it has drier, hollower stems than pasture. Once you’ve done all the hard work in getting it to the pit, it needs to rolled and sealed straight away so it doesn’t expand and take on air. This should happen immediately, as the pit is being filled. David also mentioned to be aware that cereals can be over-rolled, and if this has occurred cereals will slip out the bottom of stacks. It is extremely difficult to get them back in.
Silage density has a big impact on fermentation, so getting it right is critical to optimising quality. As well as packing it right, density is also related back to dry matter % at cutting time. A lot of dry, hollow stems will make the silage difficult to compact and spongy. A sign that the silage may have been too dry at packing time is if it feels wetter than it should in the stack at feedout. This is a possible sign of yeast activity in the stack, as water is a by-product of their action. The silage will also have a sickly sweet smell to it. Harvesting at the best dry matter possible for the season and packing and covering it quickly will give the crop the best success at achieving optimal quality when it comes out of the pit.
Monitor and measure to get it right
Dry matter and packing density of pits should come at no surprise! David has spoken to Accelerating Change previously about using monitoring and measuring techniques to ensure you are not guessing dry matters or density of stacks. Monitoring and measurement is the only way to accurately know if you are on track to achieving the product you want, and to ensure that you can fine tune you management decisions in season or for next season.