Variable seed rate on the go,do many of you use it?
- Thread starter Pilatus
- Start date
software does it for you
What about the manual variable rate seed drills?
What do you mean? The ones where you alter the rate yourself as you go along?
The GPS based ones have software that will make the average rate match your seed batch size but doing it manually you're entirely on guesswork. Keep a fairly big yet uniform field until last to balance it up at at flat rate? Otherwise you're looking at letfovers or going into the grainstore for top up seed.
- Location
- Lincolnshire
a few examples below of the maps that can be created, these all go together to make the VR seeding plan
its NDVI but will be using SAR as soon as images are available
the zones are based on soil brightness, operator knowledge, national soil survey data and 15yrs worth of yield data, ground truthed to confirm
interesting is that NDVI does seem to correlate with the zones already giving me some confidence we have them fairly right
Layers of data aren't anything new, we've been using them for years
Soil physical data (texture, stone content, organic matter, etc.), soil nutrient analysis, yield maps, farmer knowledge, earth observation data (NDVI & SAR now on it's way), weed maps (GPS mapped from our seecrop app). Soil type is always the place to start and then you can add as much information as you have available.
If you are varying seed manually, then using GPS makes this more accurate and certainly shouldn't mean any more hassle. Using satellite data and yield maps on top of your existing knowledge to create management zones can also highlight areas which could be more productive.
There is a simpler way. Variable rate seed maps can be created directly from NDVI's in both the SOYL software and the Rhiza 'Toolbox' software.
The key being to look through your existing archive of images and find individual field NDVI's that are representative of the 'normal' growth pattern for the field, and instead of creating a fertiliser plan create a seed plan using a bespoke fertiliser called 'seed' with %100 N content, which then gives you a map that you can use in your drill rather than your fert spreader.
The fundamental idea being that if the NDVI history shows consistent areas of poor or good growth over a series of years then you can predict with a degree of certainty how it will grow in future years, and you can plan the seed rate accordingly.
The resolution of the plans is also very good, as it doesn't rely on a human making a subjective decision ("this bit is good, that bit is bad" = 2 zones) instead producing a range of say 5 rate bands calibrated between high and low establishment. And unless you change the fundamentals of the soil (Drainage, fertility, texture etc) the plan remains valid for that crop for the foreseeable future: you just need to load in last years plan, and fudge the calibration numbers to allow for changes in seed weight / sowing rate.
Sounds complex, but all you need is a hour to play with the software and work out the format.
One of our farmers was nominated for arable innovator of the year 2016 for exactly this! http://www.britishfarmingawards.co....es/Arable-Innovator-of-the-Year/Joel-Prentice
Our satellite imagery is the highest resolution available at 5m so is able to pick up more variation than our competitors
That was pointed out but the manager was saying the variation would be so little that it was cheaper to stay at the farms standard practice and not pay for the technology of variable seeding. They had worked out that there might be a £3000/year saving in seed costs and it was a big might versus a new drill, more slug pellets, soil mapping, software to create the maps.
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Saving seed costs? That's a new one on me. If you use the toolboxes properly you could get it to tell you how many seeds you need across your fields for a certain drilling date I suppose. That could tell you what to order. Any savings would have to be compared to your previous policy e.g. sow 12stone/acre of wheat every year regardless of TGW.
I work on the basis that I put the right amount of seed in the right place, aiming for a more consistent yield and quality across the whole farm. By saving some in one place it could improve the perfomance in another. A net yield increase would be ideal & there certainly needs to be enough money saved or earned to cover the time, hassle and expense of gearing up for this.
I work on the basis that I put the right amount of seed in the right place, aiming for a more consistent yield and quality across the whole farm. By saving some in one place it could improve the perfomance in another. A net yield increase would be ideal & there certainly needs to be enough money saved or earned to cover the time, hassle and expense of gearing up for this.
Absolutely agree, we've never told anyone that they would be saving seed! If anything you might well see slightly more seed used where increasing plant numbers in poorer establishing areas, however this is more than paid for in the yield benefit from these. The only scenario you may want to decrease plant numbers is where there is a risk of lodging. Maximising yield in each area of the field is what we're looking to achieve
Ideally creating a seed plan at the start of the year would give you the totals, although we can also adjust this depending on what has been delivered.
- Location
- south norfolk
Maybe justifiable on big acreage but wont happen here.
Nick...
Nick...
Why not?
The two systems I've used are both cloud based, so I've never had to buy any stupidly expensive software. Importantly this means the price is calculated on a per Ha basis, which is the same for a small farm as it is for the largest.
VR sowing needs GPS (usually just an output from an existing steering system), a seed drill with electronic metering (possibly* an 'unlock'), and a cable to connect them together.
You'll need a piece of steel strip rolled into a band, 357mm across, to form a hoop covering a 1/10th of a m2, and a note book, to measure variation between the best areas in a field and the worst. If there's little variation then don't bother. If there's only 65% of the plants in the crap bits then it might be worth doing.
You'll also need a lot of perseverance, as it all takes a bit of working out.
(*- certain combinations don't need an unlock, although Trimble dealers etc will happily take your money to unlock their GPS to VR, when it can be done with the likes of an RDS drill control box FOR FREE, but they wont tell you that
).
- Location
- south norfolk
The gps stuff costs a packet to start with.my drill is all mechanical as well.i have no idea what gps steering costs but must be in the region of £10k for my old 14and 20 year old tractors.my 10 year old combination will probably see me out aswell on our 200 acres.i know of no one locally using it either and not many using gps steering either
Nick...
Nick...