Variable seed rate on the go,do many of you use it?
- Thread starter Pilatus
- Start date
I use VR seed, based on electroconductivity scanning and ground truthing. I tweak the establishment zones based on experience.
Yes, it's hard to quantify the financial benefit but in years when we've had a lot more lodging than usual like 2015 the crop was much more even. The range of ear numbs was much lower too. It just seems a proactive way of managing plant counts rather than reactively later on with VR N. in big fields where there are 5-10 different soil types I think it makes sense. In smaller fields or where there is less variation it is more marginal.
Several years of yield maps makes you question blanket treatments.
Yes, it's hard to quantify the financial benefit but in years when we've had a lot more lodging than usual like 2015 the crop was much more even. The range of ear numbs was much lower too. It just seems a proactive way of managing plant counts rather than reactively later on with VR N. in big fields where there are 5-10 different soil types I think it makes sense. In smaller fields or where there is less variation it is more marginal.
Several years of yield maps makes you question blanket treatments.
Showing my ignorance ,please can you explain when time allows,electroconductivity scanning and ground truthing 
.
On a "VERY" stony patch of soil, would it mean one would increase seed rate to make up for seed that was left on the surface due to coulter bounce in the very bad stone cover areas.
. On a "VERY" stony patch of soil, would it mean one would increase seed rate to make up for seed that was left on the surface due to coulter bounce in the very bad stone cover areas.
https://www.soyl.com/index.php/services/soyl-scan
https://www.soyl.com/index.php/services/soyl-seed
http://www.Rhiza-UK.com/precision-farming/soil-zoning/soil-zoning.html
Here are a couple of providers of variable rate seed tech. Perhaps @drifter and @Rhiza-UK might be able to explain some of this better.
Once you have your zones from either scanning or satellite photos then you prepare the establishment rate maps. Either can ask your soil scientist about a part of the field where it is really stony or you can manipulate the establishment maps yourself. I tweak mine occasionally if there is a gulley where the soil is more fertile, adding that zone and increasing the establishment rate (which lowers seed rate) then either side of the gulley there is much lower establishment because of cultivators dragging the best topsoil from there into the bottom.
Coulter bounce would result in a lower establishment rate though the higher stone content ought to be picked up by the zoning process. You may want to reduce the establishment % further based on experience.
A bit of time spent on Gatekeeper with the correct software modules can let you do this yourself - I know of a couple of farmers who created their own seed rate maps based on their own knowledge and a lot of field walking.
Attached are various maps for a block of 3 fields amounting to around 41 ha. I ran these as a trial for 2 years before rolling it out to the rest of the farm following the wet 2012 season where the normal flat rate seed fields lodged severely in places and were thin in others. Now they all go equally flat... Only joking - the yield maps still show the poorer soils yielding less and the better bits yielding more. SOYL's software uses these maps to divide your seed amongst the zones or fields accordingly. In a perfect world you would go with their recommendation and modify it for drilling date, seedbed conditions at the time etc. I just buy in about the right amount of seed then use the software to allocate it within that block of fields so the total required matches what I have in the shed. If the average seed rate is 180 kg/ha then the poorer fields might average 195 kg/ha but be balanced out by the better ones at 170 kg/ha. Don't worry about the maths, just use their toolbox to put your batch of seed where it needs to be.
Note the 65% establishment zone in the northern field, described as number 7 "heavy." That is a little valley in a 22 ha field where the crop always lodges so I asked SOYL to flip this to 95% establishment instead. Yes, it has a reasonable clay content but it is so much more fertile than the rest of the block. Why not save some seed there and put more elsewhere on the light stony bit where it never tillers out as well?
https://www.soyl.com/index.php/services/soyl-seed
http://www.Rhiza-UK.com/precision-farming/soil-zoning/soil-zoning.html
Here are a couple of providers of variable rate seed tech. Perhaps @drifter and @Rhiza-UK might be able to explain some of this better.
Once you have your zones from either scanning or satellite photos then you prepare the establishment rate maps. Either can ask your soil scientist about a part of the field where it is really stony or you can manipulate the establishment maps yourself. I tweak mine occasionally if there is a gulley where the soil is more fertile, adding that zone and increasing the establishment rate (which lowers seed rate) then either side of the gulley there is much lower establishment because of cultivators dragging the best topsoil from there into the bottom.
Coulter bounce would result in a lower establishment rate though the higher stone content ought to be picked up by the zoning process. You may want to reduce the establishment % further based on experience.
A bit of time spent on Gatekeeper with the correct software modules can let you do this yourself - I know of a couple of farmers who created their own seed rate maps based on their own knowledge and a lot of field walking.
Attached are various maps for a block of 3 fields amounting to around 41 ha. I ran these as a trial for 2 years before rolling it out to the rest of the farm following the wet 2012 season where the normal flat rate seed fields lodged severely in places and were thin in others. Now they all go equally flat... Only joking - the yield maps still show the poorer soils yielding less and the better bits yielding more. SOYL's software uses these maps to divide your seed amongst the zones or fields accordingly. In a perfect world you would go with their recommendation and modify it for drilling date, seedbed conditions at the time etc. I just buy in about the right amount of seed then use the software to allocate it within that block of fields so the total required matches what I have in the shed. If the average seed rate is 180 kg/ha then the poorer fields might average 195 kg/ha but be balanced out by the better ones at 170 kg/ha. Don't worry about the maths, just use their toolbox to put your batch of seed where it needs to be.
Note the 65% establishment zone in the northern field, described as number 7 "heavy." That is a little valley in a 22 ha field where the crop always lodges so I asked SOYL to flip this to 95% establishment instead. Yes, it has a reasonable clay content but it is so much more fertile than the rest of the block. Why not save some seed there and put more elsewhere on the light stony bit where it never tillers out as well?
I have started to try and vari rate AN a bit by eye only but anecdotally I am evening out crops which is helpful. I'm not interested in GPS/ sensor vari rate seed/ AN yet but I would like to alter seed rate on the move. Anybody ever modified an accord type mechanism to do this? Surely fairly simple if had correct sort of electric motor to wind barrel in and out? Its knowing the position that perhaps makes it a bit tricky.
I hope you've got plenty of spare seed - winding the metering barrel in and out has the potential to alter the rate by a massive amount. You'd be better off replacing the metering drive drive with an electric motor, radar/GPS and a new control box IMHO.
Noted. I think it could be done. Half a turn shouldn't make much difference.
We were on a farm walk in october in wiltshire on some very stoney light soils. Very large fields in comparison to our own and on some very rolling countryside. We were shown a 120 acre field that had used variable rate seeding as a trial which if successful they would run out over the entire acreage which was substantial. The manager who hosted the walk was not happy as the variation in the seed rate was 80kg/ha up to 200kg/ha which is normal farm practise. It was varied off some scanning machine and then a seed map created. The farm let the system do its thing and did not override anything so they could see warts and all. Basically where the rates dropped to below 100kg/ha the slugs ate the wheat. Where the rates were at 200kg/ha the slugs had attacked it but the crop was there and would go to harvest. They obviously applied pellets as per normal but the managers conclusion was if you go to variable seed rates then your slug pellet use increases so they were not taking the system any further. It was a disaster really.
- Location
- Boroughbridge, york
i dont think that writes off the idea it needs a higher minimum setting to ensure seeds per sq/m
I was a very early adopter of VRA for N and base ferts etc - to early I feel with the benefit of hindsight as back then the tech was put before the agronomy - simple grid sampling etc just to simplistic to be any use
This year I have put some of the farm into what I think is a much smarter and more joined up system with @Rhiza-UK the sampling we will do will look at a lot more than the usual basic soil samples and considers OM and C:N ratio amongst other factors
as a result we will do VRA N (satellite based but on SAR vs the traditional NDVI images) VRA seed based on zones and some VRA Lime on spring cropped ground
will be interesting, i'm still deeply sceptical but feel its time we did start using the vast amounts of data we have built up over the years to do something useful, its not as expensive as it once was either which is another factor towards it being able to return economic advantage to my busines
This year I have put some of the farm into what I think is a much smarter and more joined up system with @Rhiza-UK the sampling we will do will look at a lot more than the usual basic soil samples and considers OM and C:N ratio amongst other factors
as a result we will do VRA N (satellite based but on SAR vs the traditional NDVI images) VRA seed based on zones and some VRA Lime on spring cropped ground
will be interesting, i'm still deeply sceptical but feel its time we did start using the vast amounts of data we have built up over the years to do something useful, its not as expensive as it once was either which is another factor towards it being able to return economic advantage to my busines
There's lots of things in there that don't sound right. He must have establishment rates of well below 50% up to over 90% to get that kind of range in seed rates. Slug risk maps are something different altogether. I've not noticed any additional use of pellets but one thing is true - if you reduce seed rate in fertile clay pacthes there will be less plants to be attacked.
Still, if you don't want something to work then it's not difficult to make sure it doesn't. And vice versa!
Showing my ignorance ,please can you explain when time allows,electroconductivity scanning and ground truthing
On a "VERY" stony patch of soil, would it mean one would increase seed rate to make up for seed that was left on the surface due to coulter bounce in the very bad stone cover areas.
To explain a bit about our system and how it differs from the others on offer...With regards to the initial mapping/zoning setup process, we use soil brightness scans to indicate and map where there are variations in soil type. A soil brightness scan is a high resolution satellite image which analyses soil reflectance to indicate differences in soil texture, moisture, organic matter, stone content, CaCo3, etc. A conductivity scan does very much the same thing, in assessing where there is variation in soil type by mapping differences in a soils ability to conduct electricity. A soil brightness image scans each 5m square of the field, whereas conductivity scans are very narrow and generally run on 12m or 24m widths, using kriging (a geo-statistical technique) to estimate the conductivity in-between where the scanner runs.
Ground truthing is where we determine what is causing the variation, is it a change in geology, texture, stone content, etc. Neither scanning technique can tell you exactly what the variation in soil type is, ground truthing is required! This can either be done just using the farmer's knowledge (or anyone else that has knowledge of the farm) and any existing historical data, i.e. yield maps, geology/soil survey data of local area, previous precision farming data. Or we can task a soil scientist with conducting a full soil survey, assessing topsoil and subsoil properties.
Using our Rhiza Toolbox software, users can then set a base seed rate they wish to use and then decide how they want to vary (up or down by % or quantity of seed) based on the soil variation and the management zones that have been created in the setup process. The key to our system is that our users are fully in control of how they want to vary their applications and can adjust this quickly and easily. I wouldn't ever recommend simply following a computer model as it's likely you may well end up in the situation described earlier. The skill and art of farming is still very much required with precision farming, it simply gives you the tools to vary applications to suit different areas of the field and make more informed management decisions by providing more information.
I've attached an example of flat rate vs variable rate seed, where you can see the before and after yield map and how much more even the yield is across the field. There is also an example of a soil brightness scan, where you can see how the crop establishment in the NDVI image (greener indicates thicker crop) matches the soil type incredibly closely, and the images are much higher resolution than could ever be managed with a conductivity scan.
We also did an e-news article a little while back: http://www.Rhiza-UK.com/precision-farming/media/enews-02-variable-seed-rate.html
We're running a free satellite image offer at the moment if you would like to see what a soil brightness scan looks like on one of your own fields: https://thefarmingforum.co.uk/index.php?threads/free-high-resolution-satellite-image.159130/
Hope that explains things a little. And yes, we would recommend increasing the seed rate in very stony areas
Attachments
- Location
- Worcestershire
Wast of money. had the drill up grades got 2 drills so that was 2 x upgrades, map all fields lots of time field seed plans more time lots of time faffing with computers getting the seed plans just Wright. To be fair did work to the plan. Is it worth the time and money no way . Now gone back to the good old system of hook drill on calibrate and manually increase seed rate where I know it needs it.
- Location
- South Shropshire
Some of you guys have far too much spare time on your hands.
You ought to do something productive
You ought to do something productive
LH Agro were doing this IIRC ?
I would have tended to agree with you having wasted a fair bit of time messing about with this in the past , however whats on offer today looks a lot better to what I was playing with 15yrs ago and there does seem to be reasonable evidence of it adding to margin
we will see, as I say Im still a bit sceptical re the agronomy even if the tech and sampling methods have got a lot better, it's not expensive now and wont really slow the job down
- Location
- South Shropshire
Technology for technology's sake, unless you farm on a huge scale.
Farmers just love making things complicated and expensive.
Farmers just love making things complicated and expensive.