Just as many people were about to begin planting, rain has halted progress. Rainfall amounts have been very variable in recent weeks, with over 80mm for the month in many southern counties and less than half that in many other areas. There was an amount of planting done in January and hopefully this will not now suffer the consequences of excess wet.

Be ready with fertiliser:

We are now in February so it’s fertiliser time again as growth is likely in the coming weeks. This means nutrients will be needed to fuel this growth.

Application is very much a matter of judging timing against signs of visible growth and weather prospects. Urgency is influenced by where you are, crop condition, ability to travel and the likelihood of growth or heavy rain.

Lime or soil pH remains the most important factor to get right. If pH is low for your crop then apply granular lime shortly. Nitrogen, P, K and sulphur are the other main nutrients to be applied now. Rates depend on the crop being grown, the soil index levels and previous yield levels. A 9t/ha crop of winter barley on an index two soil where straw is removed should receive 44kgP/ha plus 103kgK/ha to meet crop needs and build fertility.

Sulphur is an important nutrient for worn ground, especially on lighter soils. This could be applied using a high S first nitrogen such as ASN (24%N + 14%S) or sulphate of ammonia (21%N+24%S), or applied throughout the season in low-S fertilisers such as compounds, SulCAN, urea+S etc.

The amount of S depends on the crop, soil type and previous management. Some S should be applied with the first nitrogen. Rape needs 40-50 kgS/ha, while cereals need 20-25 kgS/ha – official recommendations are somewhat lower.

Winter rape and barley:

Winter rape is the most urgent crop for N, followed by winter barley. Rape needs early nitrogen to drive canopy growth but the amount depends on the level of canopy already present. Canopy could vary from very little following pigeon grazing up to a GAI of 2.5 where a crop was sown very early.

The presence of more canopy means less N is needed to produce the target GAI of 3.5. This needs to be calculated for each crop. Roughly 120-140kgN/ha is required to get from GAI 2 to 3.5 or 170kgN/ha to get from 1.5 GAI.

Winter barley crops also need to develop canopy but the primary yield driver is ear number and this means tiller retention. Early nitrogen is important to help prevent leaf and tiller loss as the crop begins to grow. This has already been happening in January due to the mild conditions.

Growth in the absence of fertiliser means that plants will scavenge on themselves to feed new growth – this is what causes crops to go yellow. So, many crops might now benefit from a small application of nitrogen to keep them ticking over. This should be as little as 5-10kgN/ha for the moment with more later as growth rates increase. The main nitrogen split would still be two to three weeks away if and when the weather settles down.

Read more

Watch: In the fields – oil seed rape

Watch: In the fields – winter barley

'Very difficult' to achieve a reduction in fertiliser prices - Creed