The numbers stack up for NZ bred proprietary clover

Agricom is dedicated to developing forage solutions that deliver real value on farm.

A recent trial conducted near Lincoln, Canterbury assessed the performance and ability of Agricom’s modern white clover proprieties to increase annual production compared to a commodity clover (Huia), under synthetic nitrogen limitations in a standard ryegrass mix.

Once established and stabilised, the trial clearly demonstrated the genetic advantage of proprietary white clovers, with the varieties Brace and Attribute delivering an average of 3 tonnes more dry matter per hectare than Huia in a 12-month period (refer to Figure 1).

Agricom’s white clover advantage trial was established in spring 2021 to compare five white clover cultivars – Huia, Nomad, Tribute, Brace, and Attribute – sown with Three60 perennial ryegrass.

A consistent ryegrass cultivar and sowing rate were used across all four replicate plots, allowing for a fair comparison of pasture quantity and quality across the different clover types.

Fertiliser was applied to the trial at 190 kg N per ha per year, using a complex blend to ensure phosphorus (P), potassium (K), and sulfur (S) were non-limiting factors.

Under the full cut and carry system used in the trial, nitrogen was intentionally limited to encourage nitrogen fixation by the clovers.

This restricted nitrogen return was important to prevent full white clover dominance and the potential loss of the grass from the trial.

Yield was measured approximately 10 times per year using a forage harvester set to a cutting height of 4–6 cm.

Fresh weights were recorded for each plot, and subsamples were taken for drying to calculate dry matter percentage.

These measurements were then used to calculate total dry matter production for each treatment.

Figure 1 presents dry matter production over a 12-month period, with each bar broken down into contributions from soil-available nitrogen, applied nitrogen, and the growth attributed to these sources.

These components were calculated based on the assumption that harvested pasture contained, on average, 3 per cent nitrogen per kg of dry matter.

The remaining dry matter shown in each bar reflects the competitiveness of the clover cultivars—specifically, their ability to either contribute additional clover growth or enhance nitrogen cycling within the system.

Clover performance and nitrogen fixation are closely linked – the more productive the clover is in a mix, the more nitrogen is fixed.

This makes clover competitiveness with modern ryegrass a critical factor in long-term success.

The large-leaved white clover Brace performed exceptionally well in the cut and carry system, thriving in the productive grass mix used in the trial. Its outstanding result highlighted its suitability for these conditions.

Both Brace and Attribute, being modern white clovers, have been specifically bred to perform in dense, modern ryegrass pastures, with strong autumn and winter vigour to avoid being overshadowed during these periods of grass dominance.

While all white clovers grow vigorously in late spring and summer, it’s their ability to compete in autumn and winter that ultimately determines their long-term contribution to a pasture system.

While these results highlight the competitive advantage of Brace and Attribute in terms of dry matter and total pasture production in a rotational cutting system, both cultivars also perform exceptionally well under grazing—the system they were bred and selected for.

Brace is particularly well suited to dairy, finishing, and hybrid ryegrass pastures, while Attribute fits across most pasture systems, showing strong performance under more intensive grazing systems.

Incorporating modern white clover cultivars like Brace and Attribute into pasture mixes offers farmers genuine genetic gain. These cultivars contribute to improved pasture quality, better pasture management, and valuable nitrogen cycling—all of which support greater productivity on farm.

When considering where to invest in genetic gain in a farming system, a plant that fixes free nitrogen based on how competitive and productive it is, is a good bet.

Figure 1: Lincoln white clover trial breakdown, June 2023-June 2024 (12 months)