The secret to a good clover crop isn’t luck, it’s timing

What shapes a clover? Isabelle Nölke and colleagues at the University of Göttingen investigated what affects the productivity of clover. Their study examined the effects of genes, neighbours and seasons. Their results could help improve forage production for sheep.

The team grew eight white clover populations in pure stands and mixed stands with contrasting mixture partners to find out what drives clover architecture and biomass. The experiment ran over four consecutive periods. Repetition meant the team could also measure the importance of seasons for growth, as well as examining a mix of neighbours and varieties.

“While genetic and environmental drivers of white clover architecture and productivity have been widely studied, their relative importance remains unclear, and the relationship between white clover architecture and productivity is still not fully understood,” write Nölke and colleagues. “In our one-year study, the genetic background (white clover population) and the environmental determinants neighbourhood (stand type) and season (regrowth period) explained a large percentage of variation in architecture and yield, confirming that we investigated key drivers, though they were not equally important.”

The botanists found that the variety and the neighbourhood did affect how the clover grew. However, the season appeared to have the greatest effect.

“In our experiment, the seasonal differences in the size of those architectural traits that we assigned to neighbour-specific strategies to improve resource capture, i.e. leaf area, petiole length, internode length and specific leaf area, appeared to be primarily driven by changes in light regime and temperature,” write Nölke and colleagues.

“Like light intensity and temperature, these architectural traits initially increased in size and peaked in the second regrowth followed by declines until the last regrowth. By contrast, the seasonal differences in specific petiole length and specific internode length were more likely the consequence of the losses of photosynthetic surface and of resources in the previous harvest.”

This paper is one of few that examines the effect of season on clover architecture under cutting. As a result, the study could impact improving forage for animals in real-world conditions.