Summary
This two-year field experiment evaluated how sequential herbicide mixtures commonly used in soybean production affect nitrogen cycle-related soil functions and crop performance. Whilst all herbicide treatments maintained effective weed control and did not reduce soybean yield compared to weed-free controls, potential nitrification was significantly suppressed following the third herbicide application in the first year, irrespective of dose, suggesting that cumulative herbicide exposure may disrupt soil nitrification processes without detectably impairing plant growth or yield outcomes.
UK applicability
The findings have limited direct applicability to UK agriculture, as soybean cultivation is negligible in the UK and the herbicide regimes tested (glyphosate pre-emergence through to post-emergence applications) reflect South American production systems. However, the methodology and concern regarding cumulative herbicide effects on soil nitrogen cycling functions are relevant to UK arable systems using similar broad-spectrum herbicide strategies.
Key measures
Nodulation at vegetative and reproductive stages; plant biomass; potential nitrification; ammonia oxidizer abundance; soybean yield at harvest; weed-free status; treatment combinations of glyphosate, dicamba, clethodim, S-metolachlor, flumioxazin, and fomesafen
Outcomes reported
The study measured effects of sequential herbicide applications on nodulation, plant biomass, nitrification potential, and ammonia oxidizer abundance in soybean crops over two growing seasons. Soybean yield and weed control efficacy were also assessed across all herbicide treatment combinations.
Topic tags
Dig deeper with Pulse AI.
Pulse AI has read the whole catalogue. Ask about this record, its theme, or how the findings apply to UK farming and policy — every answer cites the underlying studies.