Controlled Traffic Farming, or CTF, workshop
Pictured: Downward view of RH side of a seeder box, rear axle extension out to approx. 3m wheel centers. I understand the cost saving in choosing a small box with the pivoting center dolly wheel, but having owned on before, I am not a fan.
Disclaimer: I blog on this because it fits with a plan to use precision methods to sow cover crops and cash crops after each other, and in the overall goal of improving soil productivity.
Last week I attended a Controlled Traffic Workshop hosted by Vic No Till Farming Association and SPAA (Precision Agriculture Association) at Rupanyup, in the interests of planning machinery mods. There was much time spent on justifying the concept, which surprised me a bit: as a convert to the principle, I was expecting a few more practical ideas. The discussions though proved worthwhile and exposed the following food for thought:
– 14% wheel-over-ground coverage is a fair ballpark figure expected on a 30′ / 9m system, 11% for 40′.
– the imperial / metric debate is alive and well eg 9m or 30′ (9.14m). IF the manufacturers went to a harvester front CUT width of a metric 9.00m then the debate would be simpler. We always want the harvester to be 1. the starting point for both cut and wheel spacing 2. = or > sowing width. They nearly had me on metric till I was reminded that for the purposes of spray jet spacings, an evenly spaced 12″ or 15″ row system fits spraying systems best, or at least spraying on and inter row should fit somehow. There is also a case for 132″ wheel spacing (exact centers) over 120″.
– that managing permanent wheel tracks is one of the biggest issues. There seems to be a paradox with wanting firm wheel tracks to carry wheel loads, and not having them sink to make gutters.
– that the best way to help sowing depth near sunken tracks is to not have them – either avoid making deep tracks if possible, (eg avoiding wet conditions, using ‘tracks’ on headers) or maintaining tracks before sowing.
– that there is damage / compaction to soil on either side of permanent tracks, but it is a secondary issue.
– permanent tracks in reliably wet areas, creating gutters, can warrant the use of concrete or gravelled tracks.
– Normal treaded tyres contribute to guttering. Because we don’t need the mud-shedding so much on the harder established tracks, we get away with tyres more like Alliance 550 style tyres. (just google it).
-tracked machines seem to offer a smoother ride on permanent tracks.
– Not all RTKs are the same. It sounds as though they are all different – JD, Trimble, GPS Ag, but some offer compatibility options. This has implications for using a contractor with the same RTK system as that on your farm. The problem sounds to be the slight differences in direction readings: over long runs (eg over 2km) the spacings become significant.
– residue spread remains a big issue on harvesters, especially if carried against the uncut crop. Chaff is carried best if chopped with the straw.
– if residue is deliberately concentrated on wheel tracks (for weed control) then dust control on the tracks is a benefit.
– interrow sowing – it seems to be easier offsetting the bar and box than offsetting or nudging the tractor.
– for the sake of precision, there is an argument for using the axle from a matching wrecked harvester on the chaser bin. I think manufacturers are increasingly getting on board with custom widths
– Lastly, the increasing weight of machinery seems to have an impact on compaction and the success of the system. Therefore minimising machinery weight seems to be one of the goals. From other ‘life experiences and conversations’ I think that is a fair call, also in terms of capitalisation and productivity. And if we want to continue increasing farm size, it has implications for using ‘multiple units of machinery and labour’ which is a whole other discussion.
Postscript: It was touched on at the workshop that one of the many benefits of controlled traffic farming is in trials and tests. Even if it has nothing to do with not compacting crop soil, it makes it easy to uniquely sow or spray a strip, record the place, and record results as we like, especially to the row at harvest, for grain quality and yield, with yield mapping, sat. imagery etc. And it is relevant to covercropping because, as I’d like to reiterate, I don’t know much and need to do trials to see what will grow and what the anecdotal and measurable results are.