Exploring the short-term in-field performance of Recovered Nitrogen from Manure (RENURE) materials to substitute synthetic nitrogen fertilisers

Possible amendments to the European Commission's Nitrates Directive, such as the proposal of ‘RENURE’ criteria for the use of mineral nitrogen (N) bio-based fertilisers (BBFs) as a substitute to the Haber-Bosch derived chemical N fertilisers, is expected to open novel avenues for BBF use in the near future. Short and long-term testing of the RENURE materials in field trials will provide comprehensive insights into their crop response and environmental impacts. In this study, three potential RENURE materials (ammonium nitrate (AN) from stripping/scrubbing, ammonium sulphate (AS) from air scrubbing of pig stables, and pig urine (PU) from separated manure system) were tested in an NVZ to evaluate their short-term N effects. Although the trial experienced some weather-related effects, the selected RENURE materials performed comparably to the chemical N fertiliser with respect to agronomic yield (fresh yield_{RENURE materials}= 28 – 32 tonne ha⁻¹; fresh yield_{Synthetic NPK}= 32 tonne ha⁻¹) and post-harvest residual nitrate in soil. The soil biota response analyses demonstrated that, microbial communities responded well to the application of RENURE materials, whereas nematode communities were more structured after AS application in comparison to the chemical N fertiliser. Overall, this short-term trial exhibited comparable performance of tested RENURE materials to the Haber-Bosch-derived N fertiliser, and long term trials are recommended for further result validation.