ForOurGrowers Literature Vegetable Amenity
Talking Agronomy: Chris Martin, Early nitrogen looks set to pay divends

News

Talking Agronomy: Chris Martin, Early nitrogen looks set to pay divends

31/05/2017

Article taken from Arable Farming, June 2017.

 

I think a 'mixed bag' is the best phrase to describe crops across the region. Forward, thick crops where nitrogen was applied in good time are looking incredibly well and still have great potential if diseases can be kept under control.

The other extreme is later-drilled crops on lighter land which have suffered from the unusually dry spring and are worryingly thin, not having really responded to nitrogen applications. It's certainly a year where early nitrogen applications to cereals look like they will pay dividends. And also a year where, on many farms, following the unusually dry spring, the advantage of using ammonium nitrate over urea will be dramatic, making that deal on urea not as cheap as it looked.

The weather has also meant, despite good application practices, late April and early May liquid nitrogen applications have scorched crops badly, even on to final leaf 3.

Cereal diseases are also very variable, with septoria on fire in the bottom of early-sown wheat crops on one extreme and barely to be seen on some of the later-sown thinner crops. In early-sown forward crops, despite the dry conditions, which would normally be associated with lower septoria pressure, due to the more drought-stressed, erect growth habit of many crops, emerging leaves have been coming out rubbing directly against old leaves plastered with septoria lesions following the mild winter, so have been instantly exposed to a ready source of infection.

The good news is the dry weather allowed T0 and Tl timings to be pretty much perfect so, even with the high pressure in the bottom, the top three leaves,which normally contribute more than 90% of yield, have a good chance of remaining clean if suitable chemistry has been used and flag leaf timing is good. 

Yellow rust control has been pretty good as timings were not compromised. But a quick trip around untreated variety trials certainly highlights the value of a ell-timed fungicide programme and this disease cannot be ignored in all but a minority of varieties now.

At the time of writing in early May there is still no significant rain forecast across the region in the near future, although if I had been given a pound for every time someone said, 'once it starts raining, it won't stop' I'd have retired to a ski chalet in Val D'Isereby now. You can't help thinking Mother Nature normally has a way of evening things out, so I guess we are due a wet spell at some point. 

However, even the grass cutters which came out for first cut silage in early May, could not break the early season drought. Perhaps it is waiting for hay-time or more typically harvest for the heavens to open.

The dry, cool weather has meant a lower sclerotinia risk in oilseed rape, particularly in early to mid flower. We should, however, learn lessons from last year where sclerotinia came in extremely late in parts of the region. While it wasn't devastating to yields, as it mainly affected secondary branches rather than main stems, there was still a yield penalty. It is therefore important as an insurance policy that sclerotinia protection fungicides should cover the whole flowering period which has been incredibly long in some fields this year.

On a positive note, the dry weather has prevented canopies getting too big in many rape crops which, aided by the cool and relatively bright period from mid flower onwards, has allowed the best chance of maximising seed numbers.

When the rain comes there should still be fertiliser left to prolong green area duration and hence improve seed fill. If, and I appreciate it is a big if, the weather in June and July plays ball, all the ducks are in a row for a big rape crop this season.

 

Agronomist Facts

Chris Martin is a technical manager for Agrovista, based in the north east of England. His role is to provide technical advice to growers over an area extending from Lincolnshire to Scotland. Prior to this, he was an agronomist with the company for 15 years and continues to provide agronomy advice to a number of growers producing combinable crops in the Scotch Corner area.