Ground conditions: Well storm Denis did not disappoint. Between himself and Ciara every tillage area in the country is already above their 30-year average for February, some are average plus a half and others are almost double their average monthly level. So any further winter wheat planting looks highly unlikely and we must hope that which was planted gets up okay.

Now that we are in the second half of February it would normally be time for fertiliser, especially nitrogen, on winter rape and barley. But with so much rain about it would still be unsafe to put on a big quantity of fertiliser for fear of loss. Most crops still show no sign of urgent need for nitrogen, partly due to the smaller canopies that are conducting less photosynthesis and partly due to the low air temperatures that are holding back growth.

Fertiliser: While opportunities are not there yet, this will likely be the first job on many farms as land may be ready for spreading before it is ready for planting. As always, rape and barley are the main priorities. Nitrogen is the most obvious requirement but P & K are also very important, as is sulphur.

Barley needs N shortly to ensure that it does not go yellow and lose existing foliage as this can equate to lost yield potential. Apply around 60-70kg N/ha when it seems safe to do so. You also need to target around 20kg S/ha in the first or across all N splits.

Winter rape: Rape is more complex because of the need to control canopy size and to target a green area index of 3.5 at the start of stem extension. This requires a balance between planting date, seed rate, variety and autumn growth. The more canopy or green area index (GAI) that is already present the less N you need to apply to generate the required canopy.

Working out the GAI of the crop is easiest done using an app on your phone called Oilseed Rape Green Area Index. Put that on your smart phone then upload photos of your crop as you walk through it. Be sure to take representative photos of your crop.

Higher plant populations and more-forward bulky crops have a higher GAI and so need less early N. But they still need some N based on the green area index, at least 60 to 90kg N/ha, but there is less rush to get that on. More backward and thin crops, which are more common this year, are more likely to be between GAI 0.5 and 1.0 (or lower) and the weaker of these could push as high as 150kg N/ha shortly.

The target optimum GAI is 3.5. The general rule is 50kg N/ha in the plant to generate a GAI of 1. So if you start with GAI 1 you need to add 2.5 GAI points. This would be 125kgN in the plant tissue but to get that much into the plant would require the whole 225kgN now as N use efficiency is likely to be 60% or less. But there will be some in the soil and some in the plant and root tissues so we tend to top out at around 150kg N/ha. That still leaves 75kg to help grain fill to be applied close to the start of flowering.