Benefits of Variable Rate Seed

[ewewhat]

Does anyone have any good black and white data of how good/bad variable rate seed rate is?

Looking on t'internet and it's a bit of a rabbit hole!

Speaking to some precision agriculture reps and they say theirs is better than the competition blah blah but they produce absolutely nothing to show me the benefits apart from what their current customers say (who say it's amazing) but I want to see something concrete, non biased.

What do you guys think? Any useful info/guidance?

 

[Green oak]

I look at it this way. If I had 1000 acres of wheat to go in the ground. I know what I’ve got to dress up. If I’ve got some dressed seed left over after variable rate or I’ve got to get some more done last week in October. I think I know how I’d feel.thats my take on it.

 

[Brisel]

Actual data on increased profits? Ask a salesperson! I’ve been doing it for a few years. More even crops, especially noticeable in years of crop lodging. Makes the canopy more even and the combine driver’s job easier as it is more homogeneous. No measurable extra yield though. More even quality? Again, hard to measure but not impossible to do.
The poorer areas of the field are still poorer but ear counts are more even.

I’m still doing it and will continue to do so. Does that answer your question?

 

[Brisel]

I look at it this way. If I had 1000 acres of wheat to go in the ground. I know what I’ve got to dress up. If I’ve got some dressed seed left over after variable rate or I’ve got to get some more done last week in October. I think I know how I’d feel.thats my take on it.

The software from the VR providers allows you to allocate a fixed tonnage of seed to a field or block of fields. No worries about logistics - you’re allocating more seed to where it would do best and saving some on the better bits.

You can also use target plant populations and can use this in advance to order the right amount of seed. If you’re going to increase rates for delays then you’re going to be short which ever way you do it.

 

[Green oak]

I put 250kgs on for end of October drilling this year. On some nice dark soil near the river it was doing 5 tonne a acre. But on top of the slope in was doing 2.5 tonne. So variable rate proberly would have told me to put 400 kgs hectare on the slope. To get 5 tonne. Lol I wish it was that easy. But I see your point.

 

[snarling bee]

If you have high variability of soils within fields then it is useful to even up the crop, especially when natural weathering does not give a good seed bed on the clays. It needs managing though, and sometimes you need to be brave. There is not much cost involved so if it floats your boat, which it probably does as otherwise you would not be posting, then do it. If you can't be bothered then don't. But I wouldn't go investing in a new drill just to VR the seed.

 

[Case290]

So there is a bit to it
sorting out correct sd cards compatabe software over come that then sort out cropping program files maps. Then get drills to reading the softwear too then Good to go, but then maps need redoing every year and I struggled with remembering the program layout 12mth later. Def not worth paying for. It cost me a lot as had to up grade 2 x seed drills
did it for 2 years now back to basics much happier easier and last 2 years I've had better crop yield averages with out it . But I do know where to put a bit more/ less on. For me it ended up just more sh!t to sort out when it's not really needed, at a busy time.

 

[Stephen E]

If you had a 50 acre field that used to be 5 10 acre fields, previously you may have altered the seed rate between fields. VR will do this for you. In heavy areas with poorer establishment, a thin crop will not compete as well with black grass, so increasing the seed rate here will help.
The good parts will always yield more. To increase your average yield, you need to improve the poor areas.

 

[PSQ]

So there is a bit to it
sorting out

but then maps need redoing every year

Def not worth paying for.

For me it ended up just more sh!t to sort out when it's not really needed, at a busy time.

Some valid points. There are some workarounds, such as preparing seed maps months in advance, not the week they’re needed.
I’d disagree that maps need redoing every year. They will need tweaking perhaps to incorporate ‘lessons learned’, but the basic principle remain the same year after year.
Re software issues, cost and complexity and workload: get someone else to do it for you. If you already use a variable rate nitrogen service from the likes of SOYL or Rhiza then 80% of the work has already been done as you can accurately base seed rate on last years NDVI imagery. My VRSeed maps are based on a satellite image from 2014, as I twigged that if an area was underperforming in 2010 it has underperformed every year since to within a matter of several metres.
Don’t buy software for VRSeed, use SOYL or Rhiza’s own cloud based portals as they are always up to date and housed off site, and crucially your rep can guide you through the maze or take over completely (remotely) to create the files for you.
One thing I learned the hard way: on this farm lowering seed rates on the ‘better’ areas compromised yield, so my lowest rate is ironically the same as Grandad used when he was ploughing with horses - ‘12 stone’ / 183kg...

If the OP wants unbiased meaningful data then the only place to find it is on his own farm. Academic ag research always has too many variables to be of much use; often on completely different soils, weather or geographic location to be comparable or relevant.

 

[Gone Shooting]

Er whats the matter with just + 5 +10 0r +15 % on the rough , stiff , cloddy or under the wood bits ? Seems to work here.

 

[jon9000]

Surely the only £££ in vrs is the person selling it! I do the kiss system. Keep it stupidly simple.

 

[db9go]

Am i right in thinking that you use historically maps from the last harvest to drill the next is that correct

 

[Brisel]

Er whats the matter with just + 5 +10 0r +15 % on the rough , stiff , cloddy or under the wood bits ? Seems to work here.

Variability can be much greater than that. In these fields, the seed rate varies by 40% either side of the average. 10% is better than a flat rate.

I've got an 80% establishment zone of good soil next to a sticky bit of clay at 65%. At 300 seeds/m2 on the 85% bit you'd need 20% more seed in the 65% zone to get the same number of plants established.

Surely the only £££ in vrs is the person selling it! I do the kiss system. Keep it stupidly simple.

I cannot dispute that point! Simple is good - it hardly hurt us for decades in the past

 

[Brisel]

Am i right in thinking that you use historically maps from the last harvest to drill the next is that correct

I haven't seen it done for seed but in theory, yes. What you need to be careful of is the reasons why certain areas yield worse. Take a gravel patch and a clay patch. This year the gravel patch did much worse because it burnt off in the drought. The clay did well. Put less seed in the clay and more on the gravel. The autumn is wet and the spring too. The establishment is much better on the gravel where the seedbed is better and much worse on the knobbly wet clay. You've exaggerated the differences, not reduced them. The clay does badly but the gravel never runs out of moisture all season & goes flat yielding worse than the thin crop on the clay when you can't scrape it off the floor. Combine driver is unhappy.

Plenty of people applying P and K based on crop offtake yield maps.

IMO yield maps are a multi coloured picture of where to go and dig with a spade to see the story behind why it performed differently. There are a lot of variables & if you're drawing the wrong conclusions you can make the wrong decisions. Bad information is worse than no information.

 

[Oat]

I can understand the benefits of VRS in producing a more even plant count once the effects of soil type etc... have hopefully been compensated for by the variable rate. But if you have the same seed number across all areas, where you get less plants emerging, there is a possibility that these plants will have more room to grow and intercept light and nutrients and produce more tillers or fill more seed sites in the ear, and therefore there may not be much yield difference between this an equal number of plants.

Overall, I had heard that although you may drop the seed rate in some areas, and increase it others, overall you end up using slightly more seed than if you used the same rate across the whole field.

 

[fudge]

Er whats the matter with just + 5 +10 0r +15 % on the rough , stiff , cloddy or under the wood bits ? Seems to work here.

Nothing! I can’t prove works mind because I cannot remember what the hell I have done.

 

[Stuckinthemud]

I can understand the benefits of VRS in producing a more even plant count once the effects of soil type etc... have hopefully been compensated for by the variable rate. But if you have the same seed number across all areas, where you get less plants emerging, there is a possibility that these plants will have more room to grow and intercept light and nutrients and produce more tillers or fill more seed sites in the ear, and therefore there may not be much yield difference between this an equal number of plants.

Overall, I had heard that although you may drop the seed rate in some areas, and increase it others, overall you end up using slightly more seed than if you used the same rate across the whole field.

I’ve taken the plunge with VR to boost head counts particularly on flat field heavy soils. To me it’s all about ‘establishment’, SOYLS term for viable plants emerging out of winter. In my heavier parts of fields tillers are much less per plant in spring so higher seed count compensates.
I’ve had combine yield maps back from this harvest which shows more consistency of yield in middle of some of the fields. But the striking feature is field edges are lowest yield and slowly improving as you move to the middle. I guess traffic movements are a likely course and hence compaction and worse soil structure. I may trial varying seed rates to increase seed in these outer areas.

 

[Badshot]

I'm looking at this with soyl.
Had a good morning with my local guy, certainly makes sense to me.
I've done the ec scanning years ago, going to sit and go through the maps to alter things.
Apparently if I go onto the next level of my soyl I can use the previous two years of satellite imagery too, which will maybe help me get the areas right.


Any one else using the my soyl system?

I found it simple enough to use, one or two known little bugs, but definitely possible for me to manage it, not have to get someone else to do it.

 

[Brisel]

I've been doing my own VR seed rate plans using mySOYL for a few years now. It's pretty user friendly. My zones are based on shallow & deep EC with ground truthing by a soil scientist who has used his experience to estimate establishment rates but they did follow up with tiller & ear counts to verify the assumptions more for their own feedback than anything I asked for. See my posts above to get an idea of how 3 very variable fields were zoned up.

 

[TWF]

Are all you still doing this or isn't it worth the bother. We stoped doing VR fert years ago. I'm Just in the process of trying to get two drills to switch on and off seeding using Greenstar swath control . I didn't know if to bother going further if I got the drill controllers talking to the tractors OK. We run Gatekeeper and have dabbled with Soyl and the Courtyard Partnership a few years ago but gave up and went back to KISS (keep it simple stupid) with everything.