We have been using digestate for our N1 applications across all crops but this means we end up applying less So3 compared to using a prilled or liquid N and S product for N1 like we would use for N2 and N3. Is there a pure liquid Sulphur available at all? We don't want to use Gypsum as we can't spread it ourselves where as we do have a sprayer and fert spreader. Even if we could put all the So3 on in one go and then swap to straight N for N2 and N3 would be better.
Sulphur
- Thread starter D14
- Start date
- Location
- Ashbourne, Derbyshire
No both very high in our soil. We’ve not applied either for 10 years at a guess since we started precision soil sampling.
Clays mainly and digestate gives about 10kg/ha of so3. Ideally a straight sulphur liquid of around 30% would be good as we feel liquids seem to be more available than anything prilled.
Elemental sulphur would be slow release and your clay would retain S better than lighter soils. 10kg SO3 isn't enough. You should be up at 50-80 kg/ha total SO3 depending on the crop and yield. Plenty of good N+S compounds on the market to top up instead of straight N.
Sorry I was not clear. We do normally apply 70-80kg of so3 because we tend to use a 22n and 10so3 liquid topping out at around 250kg of N. However by putting n1 on as digestate we are loosing most of the so3 we’d get from the 22n 10so3 stuff hence why thinking straight N and separate so3 would be better.
Loosing because we are not using 22n 10so3 for n1. Instead it’s the digestate with much less so3 in it.
If we try to makeup for it on n2 and n3 then the overal nitrogen amount is much higher than we need.
No point putting sulphur on a crop in August is there!
We’ve always put it on over 3 doses starting February and then every 5 weeks or so.
- Location
- Northumberland
That chart does look at bit odd. Peak demand at harvest and still requiring after? The x-axis says days after planting, then scaled with months - suspect a cock-up in conversion.I give up.
Edit: or is that cumulative? Then it suggests that there is very little off take.
It's cumulative. The K line is certainly accurate - the wheat plant needs a lot and the peak is during grain fill. As the plant ripens off it does put a lot back. I agree about the August lines but it assumes that the seed is growing from the moment it leaves the ear. The N curve looks right too. Don't forget that N fertiliser is only 60% efficient at best so the quantities match on a well fed crop.
The reason I posted the graph was to show that you don't need all the sulphur so early in the spring, as long as it is in the topsoil and available to the plant later on. Sulphur is also even more prone to leaching than nitrogen so an excess ought to be applied to be safe.
Here's a demand graph for oilseed rape;
I give up.
I afraid the chart you posted was not clear so what do you expect.
Sounds about right. Who supplies it and any idea on the cost?