The importance of nutrition in establishing a robust OSR crop is well-understood, but it is especially important in a year when areas are significantly down going into the season. With current prices at £329/t (August 2020) and a limited choice of other break crops to choose from, a large amount of OSR will still be sown in the UK this year. Natalie Wood, Country Arable Agronomist at Yara, offers some key advice on how to get establishment off to a positive start.
”Starting with the right seed treatment gets your crop off to the best possible start,” says Natalie. “There are a couple of nutrients worth focusing on that are particularly helpful to a newly germinated seed.”
The first nutrient that Ms Wood identifies is Phosphorus (P). “P is necessary for protein synthesis, root and shoot development, and energy transfer within the plant,” however, P has very poor mobility within the soil. Using a seed treatment that contains P puts it in the correct place – near the seed – so that the newly developing roots can access it quickly and efficiently during the crucial stage of growth.”
Another nutrient that she recommends incorporating into your seed treatment is manganese (Mn), a major contributor to various biological systems in plants, including chlorophyll production and processes during photosynthesis. “Mn has a metabolic role in nitrate-reducing enzyme activity,” says Ms Wood. “Activation of enzymes plays a role in carbohydrate metabolism. A deficiency in manganese will result in decreased efficiency during photosynthesis. Using a seed treatment that contains manganese will ensure the seedling has sufficient supply to kick-start growth.”
To illustrate the difference, Ms Wood presents a trial which observed the effect of a seed treatment containing both P and Mn. The results show doubling of plant numbers and root weights over 4.5 times higher in treated plots compared to those without. What does this indicate? “The plants with more roots are better able to access resources,” says Natalie. “Therefore, as we see in this trial, they are established far better than the plants without a seed treatment containing those nutrients.”
In addition to using an effective seed treatment, placing an NPKS fertiliser at drilling will also aid establishment. “OSR is allowed 30kgN/ha in the autumn if you’re in an NVZ,”says Natalie. “However, if you’re placing fertiliser, you can reduce this to 20- 25kgN/ha due to it being more precise.” As P is unable to travel far in the soil (less than 1mm), placing fertiliser at drilling will ensure the nutrients are kept close to the seed for quick access during germination.
Creating a decent supply of biomass before entering into winter is also vital. “Once the crop is up and has reached the 2-4 leaf stage, we need to maximise its growth pre-Christmas. This can be helped with micronutrient applications. The easiest way to apply all of OSR’s key nutrients required in the autumn is to use a multi-nutrient, crop-specific product.
“There are many ways that nutrition can help improve establishment of OSR this autumn. Make sure you take the right steps to get the crop off to the best possible start and keep its momentum on an upward trajectory as we head into winter.”