Impact of cattle slurry application methods on ammonia losses and grassland nitrogen use efficiency

John Kormla Nyameasem; Mareike Zutz; Christof Kluß; Martin Ten Huf; Christoph Essich; Caroline Buchen-Tschiskale; Reiner Ruser; Heinz Flessa; Hans-Werner Olfs; Friedhelm Taube; Thorsten Reinsch

doi:10.1016/j.envpol.2022.120302

Impact of cattle slurry application methods on ammonia losses and grassland nitrogen use efficiency

Environ Pollut. 2022 Dec 15:315:120302. doi: 10.1016/j.envpol.2022.120302. Epub 2022 Oct 3.

Affiliations

¹ Institute of Crop Science and Plant Breeding, Grass and Forage Science/Organic Agriculture, Christian-Albrechts- University Kiel, 24118, Kiel, Germany. Electronic address: jnyameasem@gfo.uni-kiel.de.
² Institute of Crop Science and Plant Breeding, Grass and Forage Science/Organic Agriculture, Christian-Albrechts- University Kiel, 24118, Kiel, Germany.
³ Department of Plant Nutrition and Crop Production, University of Applied Sciences Osnabrück, 49090 Osnabrück, Germany.
⁴ Institute of Crop Science, Hohenheim University, 70599, Stuttgart, Germany.
⁵ Thünen Institute of Climate-Smart Agriculture, Federal Research Institute for Rural Areas, Forestry and Fisheries, 38116, Braunschweig, Germany.
⁶ Institute of Crop Science and Plant Breeding, Grass and Forage Science/Organic Agriculture, Christian-Albrechts- University Kiel, 24118, Kiel, Germany; Grass Based Dairy Systems, Animal Production Systems Group, Wageningen University (WUR), Wageningen, Netherlands.

PMID: 36202271
DOI: 10.1016/j.envpol.2022.120302

Abstract

Optimal manure management is required to ensure efficient nutrient supply to farmland and to avoid adverse environmental impacts. Accordingly, ammonia (NH₃) emissions associated with different slurry application techniques were investigated in grassland trials under different soil and weather conditions across Germany. Cattle slurry was applied in two dressings, early in spring and after the first silage cut, with a target amount of 170 kg N ha^-1. The application treatments comprised: trailing shoe (TS), acidified slurry applied with trailing shoe (TS + A), open slot injection (SI), and slurry treated with a nitrification inhibitor (NI) applied by slot injection (SI + NI). In addition, slurry application techniques were compared with a non-N-fertilized control and a mineral fertilizer treatment (calcium ammonium nitrate, CAN). NH₃ measurements followed each N application event. NH₃ losses were equivalent to 1-39% of total ammoniacal nitrogen (TAN) applied. The average NH₃ mitigation potential of the different slurry application techniques compared to TS was 45.7 ± 7, 21.2 ± 6.2 and 13.7 ± 8.2% for TS + A, SI and SI + NI, respectively. The use of nitrification inhibitor with slot injected slurry did not increase NH₃ losses relative to TS (p > 0.05). Mean apparent N use efficiency was two times higher for CAN (49%) than the slurry treatments (24%) but was comparable between SI + NI and CAN in five out of the eight cases. Our results indicate that mean TAN related NH₃ emissions of tested treatments (3.3, 22.6, 12.2, 17.8 and 19.3% for CAN, TS, TS + A, SI and SI + NI, respectively) were generally lower than described in previous studies. Moreover, the results suggested possible increases in NH₃ mitigation and N use efficiency when cattle slurry is applied with acidification or injection techniques. We found no evidence that NI addition to slot injected slurry, a treatment discussed as a measure to reduce N₂O emission and nitrate leaching, changed NH₃ emission.

Keywords: Apparent nitrogen use efficiency; Nitrification inhibitor; Open slot injection; Slurry acidification; Trailing shoe.

MeSH terms

Ammonia* / analysis
Animals
Cattle
Fertilizers
Grassland
Manure
Nitrogen*
Nitrous Oxide / analysis
Soil

Substances

Ammonia
Fertilizers
Manure
Nitrogen
Nitrous Oxide
Soil