Abstract
Globally, food production systems need to undergo significant changes to become more resilient and effectively balance high yields, soil functions, and biological diversity. Regenerative agriculture is promoted as a system of best management practices aimed at strengthening nutrient cycling mechanisms which increase soil organic carbon (SOC). However, there is a lack of research in New Zealand regarding the effects of regenerative management on SOC and other aspects of soil health.
The objectives of this study were to determine how SOC is affected by: 1) regenerative and conventional management treatments, 2) pasture diversity and community composition, and 3) soil health indicators.
Soil samples were collected from five pasture and cropping treatments and SOC was determined through loss on ignition and/or CN elemental analysis. Generalised linear models were used to determine effects of treatment and depth. Pasture diversity was surveyed and community composition was analysed using principle components analysis. Soil health indicators including visual soil assessments (VSA), aggregate stability, pH, water holding capacity (WHC), and bulk density were also measured.
Key findings revealed that SOC stocks were significantly higher in the top 10 cm in regenerative pastures (60.33 t C/ha) compared to conventional pastures (53.12 t C/ha). SOC stocks were not significantly different among regenerative cropping, improved pasture, and unimproved pasture treatments. Species richness and functionally diverse assemblages strongly and positively correlated with SOC stocks in the top 10 cm. VSA scores and aggregate stability did not meaningfully correlate with SOC stocks. WHC positively correlated with SOC, however, bulk density was a stronger predictor.
These findings highlight the importance of conducting long-term investigations on regenerative agriculture practices and SOC stocks. Further research is necessary to deepen our understanding of how management treatments influence SOC dynamics. This research provides valuable insights for farmers of the potential effects of management practices on soil health.