Imaging; usefulness, payback, cost/benefit

[Secret Agronomist]

Is anyone using any of the imaging systems in anger? There seems to be a plethora of these appearing and I have meddled with the Agrii contour system. They seem to raise more questions than they answer and on generally light soil they just show lack of moisture, IMHO. They could however be used to vary fungicide and PGR application a bit more by using vari rate. Maybe do the same with fert? If so how much should you vary things by?
Discuss

 

[Brisel]

I've tried drones & satellite NDVI imagery for N applications. Other than saving me some money on N in 2018 with some large osr canopies, it has never covered its costs if I value my management time properly. Last year in osr you could vary the N all you wanted but the cameras could not see the CSFB larval burden. Early summer droughts on lighter soils also spoiled any responses to March/April applications. Cereals don't seem to respond particularly well. They already have a N Sensor here in my new job so I'll see how that goes - we've got some very variable wheat where it wasn't put in very well and rained constantly afterwards. There's an opportunity to cut back the spend in wet holes & dodgy headlands.

What other imagery did you have in mind? I've tried electroconductivity scanning soils for varying establishment rates & seed. Yes, I got a more homogenous crop but no significant yield lift per field. It did reduce the lodging in parts of the field with a history of going down, so that has a value when you consider the hourly cost of a harvesting team regardless of tonnes/hour as well as yield loss from lodging. Rhiza/Agrii Contour use soil brightness mostly (I think) for creating soil type zones which is cheaper than a scanner over the field. Part of the value is in the ground truthing by a soil scientist or the grower which is used to estimate the seed establishment %.

Smart sampling for ph, P, K, Mg etc? Done by soil zone or just a 100m grid? Good in a very big and variable field. Not worth it in more even smaller more fertile fields. A good experienced lime sampler is just as good as, if not better, than a GPS sampler. Send your samples to the lab where they grind up the inert calcareous stones to neutralise the acid soil next to it and you get false readings. SOYL said pH 8.2 in a patch of clay cap with clubroot - lime man said 5.8 and showed me the previous maps he'd done years before. I had a ride around with him to see for myself.

So, what is constraining yield? Pigeons, rabbits, drainage, sunlight, aspect, compaction, plant population, canopy, nutrition, moisture etc? A technicolour image doesn't tell you that. It does direct you to the bits that need further investigation with a spade, sample bag, tissue test and an experienced eye. Don't forget to repeat on the good bits as a comparison too.

What do you need to justify the expense of all this tech? Big responses in high value/high potential crops IMO. Messing around in a crop of spring barley on 10 acres of sand that might die in June without rain isn't going to get you your money back.

Why the pretty pictures? Attention to detail when you can't see with the naked eye or don't have the time to put boots on the ground often enough, I suppose. What questions did it raise with you @Secret Agronomist ?

 

[fudge]

You are rather missing the point. These services can be marketed to landowners who don’t know how to manage their crops. A useful income stream for someone. Obviously being a Luddite I would never spend any money on this stuff without seeing repeatable evidence that it adds to profitability.

 

[Brisel]

I don’t know who does such field scale trials independently other than growers, but there are a lot of users of these techniques who seem happy enough that it has a benefit. I've met & chatted to lots of these fellow users at technical meetings about what does or doesn't work for them. I haven't met many who have used it then scrapped it, but then again I'm unlikely to see many of these - it's not human nature to admit that you wasted a lot of time and money on something that didn't work for you. Of course there will be some who will slag it off having never tried it. Yes, it's hard to find "repeatable evidence!"

 

[Steevo]

@Phil P

 

[Lincsman]

You need to predict future weather with very high accuracy before anything like this will be useful.
Something telling me the far side of the field never yields quite so much is no benefit, I know this and there are several good reasons and nothing has changed it before and wont in future, there is more chance of making the good side yield more.

 

[Phil P]

I’ve been using @Rhiza-UK contour/toolbox software for about 4 years now.
Satellite images have there place and we have picked up some very useful data from them, however you have to put the whole package together to see any difference. As @Brisel says you also need the time to do it, these systems don’t replace boots in the field but can help with knowing where to walk!

We do every from VR seed, p&k, and depending on the season VR N, the N is a hard one to monitor and see the difference/justify. I’m hoping to do some field scale trials with VR N next year, the NDVI images come in handy to monitor these sorts thing. We did some cover crop trials a couple of years back and these show up still on the NDVI and yield maps!

In a nut shell, if I was farming any less it probably wouldn’t warrant it and if I was on a massive acreage I probably wouldn’t have the time to get the most out of it. But on my current scale with our very variable soil types (stone, clay and black sand all in the same field) I think it has its place.

 

[Secret Agronomist]

"it's only £1 per acre"!!!!!
The real benefit is on the higher value crops but its finding what to change is the real problem.
On potatoes you could use it to see what effect a treatment would have and it does show up differences between seed stocks, but by the time you see a difference it's too late to do anything. Soil texture analysis would be good on root crops to vary seed rate as (especially with potatoes) you get big differences in tuber numbers between soils types, and could possibly be applied to carrots as well to increase seed rate in heavier parts of fields.
In an ideal world all of these things would be repeatable from year to year but as we know the weather varies too much for that!

 

[Secret Agronomist]

Just been looking at the maps (can't seem to upload them here) most of the variation is purely soil type and therefore moisture driven. Therefore in irrigated potatoes they are very even. In the past we have tissue sampled poorer areas and there is usually no difference in nutrient levels between good and bad. You can sometimes see variation between seed stocks and sizes before full canopy, but these are the sort of differences you can already see by eye.

 

[ajd132]

I think a lot of this stuff is gimmicky and adds little value, apart from perhaps vari seed of you are on variable soils.
variable p and is an utter fallacy.
I’m fairly convinced this kind of thing makes people feel like they are doing something clever but at the moment I cannot really see the value having tried some of this stuff. I’m not paying hutchinsons to tell me I have a sh!t headland or corner that should go into stewardship. This is obvious. Data for data’s sake.

 

[Secret Agronomist]

I vari K and lime as the lime needs to be as spot on as possible for root crops and the K because there are low yielding areas that have been built over the years and can have reduced dressings now and also some fields only get straw from carrots on them in parts which influences K a lot, also if you a vari rate spreader and are going anyway its easy to do. I have lots of P so in general cereals get no bagged P, and sporadic doses of chicken litter etc.
So its horses for courses but I would say that so far 1ha soil sampling is giving me the best bang for buck. I could go to 1acre but as it is I'm getting pretty good resolution.

 

[ajd132]

I vari K and lime as the lime needs to be as spot on as possible for root crops and the K because there are low yielding areas that have been built over the years and can have reduced dressings now and also some fields only get straw from carrots on them in parts which influences K a lot, also if you a vari rate spreader and are going anyway its easy to do. I have lots of P so in general cereals get no bagged P, and sporadic doses of chicken litter etc.
So its horses for courses but I would say that so far 1ha soil sampling is giving me the best bang for buck. I could go to 1acre but as it is I'm getting pretty good resolution.

Fair, I should have caveated I was talking in terms of combineables

 

[Brisel]

I think a lot of this stuff is gimmicky and adds little value, apart from perhaps vari seed of you are on variable soils.
variable p and is an utter fallacy.
I’m fairly convinced this kind of thing makes people feel like they are doing something clever but at the moment I cannot really see the value having tried some of this stuff. I’m not paying hutchinsons to tell me I have a sh!t headland or corner that should go into stewardship. This is obvious. Data for data’s sake.

My best savings have been with P. When a big field varies from index 0 to index 5 but averages 2 it saved £68/ha/year for 4 years in allocating the fertiliser and lifted wheat yields by 0.4 t/ha though I'd tweaked a few other things and they may have been better growing years. Yield maps used in conjunction with nutrient maps and a chat with operators who have worked those fields for years soon tell you where the stewardship needs to go.

 

[deleted user 837354]

I think a lot of this stuff is gimmicky and adds little value, apart from perhaps vari seed of you are on variable soils.
variable p and is an utter fallacy.
I’m fairly convinced this kind of thing makes people feel like they are doing something clever but at the moment I cannot really see the value having tried some of this stuff. I’m not paying hutchinsons to tell me I have a sh!t headland or corner that should go into stewardship. This is obvious. Data for data’s sake.

It's about creating an income stream for big companies in the face of declining numbers of approved chemicals and ever fewer new actives being approved in the first place. You sign up for it with your big national company and are then hooked on their agronomy 'package' and pretty maps. In time, your entire operation becomes reliant on variable applications because you are convinced of the cost savings.

It's exactly the same with the ever prevalent assurance schemes, NVZs, nutrient management, livestock training courses and all that bilge. Create an income stream where none existed before.

 

[Secret Agronomist]

My best savings have been with P. When a big field varies from index 0 to index 5 but averages 2 it saved £68/ha/year for 4 years in allocating the fertiliser and lifted wheat yields by 0.4 t/ha though I'd tweaked a few other things and they may have been better growing years. Yield maps used in conjunction with nutrient maps and a chat with operators who have worked those fields for years soon tell you where the stewardship needs to go.

"Here" everyone else does grain and fert for spring grain and some are doing TSP down the spout for winter cereals as well.
I just do flat rate P on the veggies as the carrots get a complex mix of NPKSBCuNa etc etc and nipping round with a spot of TSP which is immediately locked up is pointless. For the spuds they get flat rate of NP down the spout after getting vari rate MOP on the stubble and flat rate polysulphate pre planting. Could in theory cut that down to one pass and just spread a blend but potatoes esp. benefit from fert placement.

 

[deleted user 837354]

"Here" everyone else does grain and fert for spring grain and some are doing TSP down the spout for winter cereals as well.
I just do flat rate P on the veggies as the carrots get a complex mix of NPKSBCuNa etc etc and nipping round with a spot of TSP which is immediately locked up is pointless. For the spuds they get flat rate of NP down the spout after getting vari rate MOP on the stubble and flat rate polysulphate pre planting. Could in theory cut that down to one pass and just spread a blend but potatoes esp. benefit from fert placement.

Surely DAP would be preferable for anything down the spout?

 

[Brisel]

Surely DAP would be preferable for anything down the spout?

That could be the NP they are referring to

 

[Secret Agronomist]

NVZ so anyone who uses autumn P will be on TSP, DAP for the spring but I use liquid for the spuds as a more concentrated band and no concerns if its damp.

 

[matttargett4]

There’s a grass field across the road from my house on the hill, we dribbled it with slurry early October, there is a miss probably 8m wide and 50m long, if Neil Armstrong was up there he could see it, the miss is jcb yellow and the field is like wheat in April.
I also have a field of maize stubble with mustard cc about 6” high, on the last couple of runs the drill ran out of seed in one side so there are some 3m wide stripes of bare dirt.
guess what, sattelite ndvi imagery can’t find either, imagine that slurry was on a growing crop in April and you want to use the ndvi images to create a vari rate map for your last n application, would it be useful?

 

[cricketandcrops]

NDVI has an issue later in season as it all looks the same, I have examples where the first N application is shows differences by second and third it doesn’t. However look at it differently and can spot the lighter land.....however people tell me VR Satellite N evens it up so much after first application.....not sure it does it is the effect of NDVI saturating the green out. If you want to see for yourself try Atfarm, use NDVI later in growing season to get a field view, then switch to N-Sensor view and see the difference.