13 January 2025. Paul McIntosh, Pulse Australia and WeedSmart.
It must be that time of the year for my reminiscing on past events and farming practices. However, I am moved to talk about our current placement of seed in the ground practices, after looking at some soybean planting recently.
From years of family farm experience, soybeans can be a bit flakey. By my technical term in flakey, I mean that good levels of germination and vigour are important in all seed destined for planting a crop and soybeans sometimes fall down in that sector. Also important is adequate nutrition in the ground where the actual seed crop is growing in from the season before, plus add in good sunny conditions at harvest for obtaining a seed crop with vigour and germination. Then, you add in the variety choice plus cool storage conditions with no excess heat to get a successful seed crop.
Having got all that correct, all you need then is friable soil conditions and a planting machine to handle an accurate seeding rate at a reasonable depth with good moisture. Simple, isn’t it?
Well, not really when you talk about our mostly rain-fed or dryland cropping systems.
The planter setup is very important for a good resultant strike or aim, which is to achieve an even distribution and emergence of plants.
One issue that can occur depending on soil type and the farming system adopted, is soil crusting. Crusting on the paddock surface can occur when rain happens immediately after planting, and before your plants emerge. My long experience with soys shows that they are particularly weak to break through potential soil crusting issues. Other plants like sunflowers and chickpeas are reasonably successful at breaking through soil crusts if needed.
With the range of new age planters with fancy metering systems, seed placement is extremely important and surprisingly accurate these days. However, spear or knife points or double disc openers and many other variations have taken over from old duckfoot points on the old planter in the photo.
Press wheels cover a wide range of options and have taken over from light lever harrows and a home made rubber tyred rollers.
Press wheels have taken on a narrow solid rubber wheel on the planter backend, closing the slot or seed trench and giving seed soil contact. There's nothing wrong with that, except we always start a day or two too early after planting rain and that can leave the wet press mark going hard and sheer. It may not specifically be soil crusting, however, the end result of your cotyledons pushing through the ground and hitting the hard pressed, dried out soil is not good. Putting some small chains as loops behind the planter units will pull some loose soil over the wet hard layer of the press wheel or seed slot to reduce this occurring.
Back onto soybeans. The most successful soybean planter we had on some of our family farms crusty top soils (before the zero till phenomenon helped our soil structure), was a Nodet Gougis. Its press wheels were a real breakthrough for surface crusting soil, due to the fact that the centre of the press wheel was fitted with a scalloped out softer rubber material and it left the soil like a inverted porridge dished shape along the planting furrow.
The benefit of this was if rain and then crusting occurred before emergence, then the top of the dish shape would crack open right along the seed trench to allow emergence of seedlings.
With over one metre or 40 inches in the old language falling on my Highfields home in 2024, that is a good start for soil moisture accumulation in 2025.
That’s all folks.
An old Shearer combine planter c/w covering harrows.