Seventy-five years of insight – the impact of the Ukulinga very long-term grassland experiments

Abstract

Two of the world’s oldest grassland experiments began in 1950/51 in Pietermaritzburg, South Africa. The Burning and Mowing Trial (BMT) tests how summer mowing and dormant-season burning or mowing regimes affect mesic grassland. The Veld Fertiliser Trial (VFT) examines how nitrogen, phosphorus fertilisers and lime influence grassland productivity, composition and diversity. Seventy-five years later, their impact was assessed through research output and value for education and networking. All published papers and their citations were identified, with key themes, leading authors and citation patterns of the top 10 papers from each trial analysed. A total of 26 and 24 peer-reviewed papers, cited 1 652 times, have been published from the BMT and VFT, respectively, with publication rates rising since 2000. Studies addressed treatment effects on soil, plants, invertebrates, microbes, regional comparisons and remote sensing. South Africans led authorship, with strong USA participation, and the top-10 papers reached a wide multinational audience. The Ukulinga LTEs demonstrated the vital role of regular burning or mowing, revealed how fertilisers can negatively impact grassland, and highlighted the importance of treatment interactions in shaping ecosystem dynamics. As key sites for research collaboration and education, they should be maintained long-term to advance understanding and address new questions.