Both maize and clover grass are important roughage crops on cattle farms. A larger proportion of maize in the feed for dairy cattle can reduce their emission of the greenhouse gas methane. But feed production also has a climate footprint, which is important to understand and limit. As part of a webinar in connection with the Plantekongres 2022, Professor Søren O. Petersen will focus on the conversion of grasslands, which is an important source of emissions of nitrous oxide.

Risk of nitrous oxide emissions during the conversion period

"If the proportion of maize in the crop rotation increases, there will be less space for grass, and this will increase the relative importance of the conversion phase with the risk of nitrous oxide emissions compared with the growth phase, where carbon is built into the soil," explains Søren O. Petersen.

Plant residues decompose after the conversion under conditions which are determined by the conversion method, soil type and climate. Interactions between these factors mean that the emission of nitrous oxide can vary dramatically each year. Søren O. Petersen will illustrate this in his webinar using results from several experimental years.

The webinar will be held on Thursday 13 January 2022 at 15.15 - 16.00.

Nitrification inhibitors

Ammonium supplied via fertilizer can be converted into nitrate in the soil through a microbial process called nitrification. If the formation of nitrate is greater than the plant uptake, or if it occurs during a period without plants in the field, it poses a risk of nitrate leaching. Inhibition of nitrification can therefore contribute to better nitrogen utilization, and for this purpose so-called nitrification inhibitors have been developed. It is a group of chemical substances, all of which have the property of inhibiting the first step of nitrification, whereby the nitrogen remains in the plant-available ammonium form.

Therefore, nitrification inhibitors are now recommended for fertilizing maize on sandy soils, where the risk of nitrogen loss in the spring period is particularly high. New Danish figures confirm that both leaching risk and nitrous oxide emissions can be reduced when using these nitrification inhibitors. However, the risk of nitrous oxide emissions from plant residues when changing grass may also be limited. Søren O. Petersen will shed light on this on the basis of experimental results.

Hear much more at the webinar "Climate-friendly roughage production" on Thursday 13 January 2022 at 15.15 - 16.00.

Virtual Plant Congress

This webinar is part of the Plant Congress 2022. Again this year, the Plant Congress is being held virtually due to the Covid-19 pandemic. But the content is still the same, now you can just follow the many exciting presentations at home from the living room when they are held as webinars. In addition to this webinar, you can hear about:

• Changes in carbon content in Danish agricultural soil - The latest figures for Danish agricultural soil's carbon content are presented. 
   
• Reaching the target with zero emissions - Production of fertilizer and nitrous oxide emissions from the field are heavy items in the climate footprint of cereal crops. Hear about a new strategic effort to reduce greenhouse gas emissions from plant production and how you can reduce emissions in the field using new cultivation strategies.
   
• Diseases in cereal crops - Get the latest experimental results and strategies for controlling fungal diseases in cereals presented. Also hear how the new fungicide Balaya fared against Septoria in winter wheat in 2021, and get an idea of ​​the future use in winter wheat. In addition, there is a focus on fungal control in other cereal crops.

Read more about the Plantekongres 2022 here www.plantekongres.dk (in Danish)