Agronomy Advice
February 08, 2023

Spring Nutrition Isn’t Just About Nitrogen

By: Natalie Wood
two farmers in a field reviewing the soil
two farmers in a field reviewing the soil

However, it’s not all about N, sulphur (S) and phosphate (P) in spring are also important. Sulphur is a key nutrient in plant growth and has a close relationship with nitrogen, increasing the uptake and utilisation efficiency of N – therefore it is a simple way of increasing your nitrogen use efficiency (NUE). The form of sulphur is important however, sulphate is immediately available to the crop and is therefore the most efficient way of supplying the crop in the spring. Nitrogen and sulphur should be applied together for maximum NUE, therefore a compound NS or NPKS fertiliser is an ideal choice.

Thinking now of phosphate, research of how P behaves in the soil shows it doesn’t become significantly plant-available until soils reach a temperature of 8°C and above. If we think of soils at the end of February, they’re not likely to have reached this temperature, therefore we are feeding the crops with nitrogen and encouraging growth without them being able to access P from the soil. Couple this with a potentially poor root system and the crop can soon begin to struggle.

The way to combat this is to apply some fresh P in the spring, even if it is a small amount such as 35kg/ha, to give the crop an available source of P whilst it’s waiting for soils to warm up, where it will then be able to access soil-P.

For a simple and effective approach, using a compound NPKS such as YaraMila 52S at the first nitrogen timing in the spring will give the crop the 4 key nutrients it requires at the start of its regrowth and set it up for increasing its biomass successfully.

Another way to get phosphate into the crop is to use foliar-P. Foliar applications of P are very efficient, but you can only put on small quantities compared to the overall crop requirement therefore it has to be included alongside the main fertiliser. If using foliar-P, it should be applied at T0 and should be no later than 7-10 days after the main fertiliser is applied, this way the two work together to get the crop growing and ensuring energy transfer is working optimally within the crop as it goes towards the rapid phase of growth in the spring. YaraVita Crop Boost contains P, K, Zn, Mg and is an ideal product for the T0 timing to kickstart growth in spring.

Therefore, a simple strategy is use of an NPKS fertiliser followed closely by a foliar-P application to get the most out of cereal crops this spring.