Nitrogen supply for organic winter oilseed rape

DiverIMPACTS Practice Abstract

Resource explained

In cool, moist and dry soils, nitrogen (N) mineralisation can be inhibited, which leads to an insufficient N supply and yield losses. Modern varieties of winter oilseed rape require a lot of N in early spring. Fast-releasing fertiliser application in autumn and spring can complement fertilisation via crop rotation and manure before sowing, and prevent a lack of N in spring. Optimal fertilisation ensures that current oilseed rape varieties reach their full yield potential. This Abstract, created as part of the DiverIMPACTS (Diversification through Rotation, Inter-cropping, Multiple Cropping, Promoted with Actors and value-Chains towards Sustainability) project, provides practical guidance of how to maximise on N in a sustainable, efficient way.

 

Findings & recommendations

  • To maximise on N, it is recommended that the ideal time for cultivating oilseed rape (OSR) is after grass-clover or legumes.
  • After growing grains, apply about 30 tonnes of manure or manure compost per hectare before cultivating OSR.
  • In dry conditions in spring, an early single application of N is preferable to two smaller applications.
  • In the case of slurry with a low N content, two applications are often required because a maximum of 40 m3 of slurry can be applied at once. Regularly analyse the N content of your slurry (or commercial fertiliser or liquid digestate if using) so you can be sure to apply the correct amount.
  • It is recommended that you initially carry out tests under your farm conditions. This Abstract provides practical guidance on how to do this, along with guidance on how to visually examine plants, how to carry out an exact evaluation using plant samples, and how to evaluate yield per plot during harvest.

The overall goal of the DiverIMPACTS project is to achieve the full potential of diversification of cropping systems for improved productivity, delivery of ecosystem services and resource-efficient and sustainable value chains. View the project website and other practice abstracts here.

Summary provided by:

Janie Caldbeck

Related articles

Establishing summer cover crops before winter cereals in low tillage systems on sandy soils

Abstract created as part of the DiverIMPACTS project outlining some of the benefits that can be attained from establishing summer cover crops on sandy soils...

Farming Oilseed Rape without Neonicotinoids

With pesticides increasingly linked to harm to bees this report examines current ways of growing oilseed rape without neonicotinoids.

The End is Nigh, The End of Nitrogen

Footage of a discussion held at Groundswell 2022, organised by Agricology, about the impacts of reduced nitrogen use and ways in which farmers are moving...

Companion cropping

Jake Freestone talks about his experiences of growing oilseed rape with buckwheat and vetch and highlights benefits he has observed.

Julian Gold

Julian Gold is farm manager of 800 hectares of Hendred Estate in Oxfordshire on the edge of the Berkshire Downs. He talks about how he...

Dan Bussey

"We are working towards a regenerative agriculture model, restoring soil that was becoming less and less fertile and having symptoms of poor health such as...
To top