Peter Waltham, Agronomist
Somerset, Wiltshire, Dorset
We have three situations in the field with our winter wheat crops this season.
We have some sensible-looking crops that went in quite well on relatively well-drained soil during the dry period in late October/early November, despite awkward conditions. These grew away before they got wet feet and have pretty good potential. However, they are very much the minority.
Many other crops are a mixed bag and a wall-to-wall crop in a field is a rarity. These have less potential due to wet patches and, in many cases, lost headlands. It is highly likely these crops will need some extra help in terms of nutrition as they are fairly backwards and lack vigour.
Then we have very late-drilled crops which have only just come through – some were drilled as late as mid-February.
We are looking at three different management situations when it comes to nutrition. The first set of crops will be managed pretty much as normal.
With the more backward ones, we are going to have to feel our way through. Firstly, we need to improve the health of these crops, so they can pick up nitrogen and other nutrients more effectively, which will translate through to yield and hopefully provide a reasonable gross margin come harvest.
Early nitrogen will be key to encourage tillering, where fields will travel. There will be little if any residual N in the soil at the moment, given this is the second wet winter in a row.
Phosphorus is a key element when it comes to early growth, so we need to ensure plants are in the best shape to make the most of it.
Calfite Extra and Luxor from Agrovista’s Innovation Range are going to be important on more backward crops and where soil indices are low, to pre-empt any deficiency rather than waiting for it to manifest fully.
I invariably use the two together. The phosphite element of Calfite Extra helps stimulate rooting and nutritional scavenging. The Luxor component delivers increased phosphate delivery and the fulvic and humic acid components support microbial activity in the soil.
With that in mind, I will probably apply some L-CBF Boost early on as well on soils that have taken a hammering. This product is a food source for soil microbes and fungi, increasing their numbers which, in turn, improves the availability of key nutrients for the crop.
We have to pick and choose what we're going to do. Everything will be more case-by-case this season than it's ever been.
My overall approach is to try to maximise the genetic potential of the crop. I use sap testing in the field to measure available nutrition in the plant as close to real time as possible, which is key to optimising the expression of those genes in the field.
We will be doing sap tests about a week or so ahead of T0, and the same ahead of T1 and T2.
Some of the very late crops are only on their way through, so we need to keep an eye on them. At least they will have missed the worst of the blackgrass!
They will need to be managed a bit differently again. Once they begin tillering we may well look at Calfite Extra/Luxor, because they are going to need an extra kick. We can then consider what other bioscience products we might need to apply to keep these crops moving at a good pace.
* Whilst this article is about nutrition, when it comes to plant protection products it is worth noting that late-drilled crops (sown after 31 January) are considered spring crops. Pesticide labels can differ considerably between winter and spring wheat.