Forage for Knowledge

Discussions with fellow consultants Bess and Sean, along with what they are seeing on the ground, have highlighted this as we head out of drought conditions. Across much of the country, pastures are greener, and grass, herbs and clovers are coming back to life.

However, comments from around the country and farm data show clear differences between farms. Those that allowed average farm cover to fall very low during the drought, in some cases down to 1,500 kg DM/ha, are recovering much more slowly. With little cover remaining, grass plants are only producing their first and second leaves, and growth rates remain low.

By contrast, farms that maintained an average farm cover of 1,900 to 2,000 kg DM/ha have recovered more quickly and are getting higher growth rates.

What the data shows

Last week’s Forage for Knowledge data supported these observations.

Farms with an average farm cover of 2,050 kg DM/ha or less (ranging from 1,700 to 2,050 kg DM/ha) recorded growth rates of 0 to 20 kg DM/ha/day. In comparison, farms with average farm covers above 2,050 kg DM/ha recorded growth rates between 39 and 72 kg DM/ha/day, with only one exception.

These results were not simply explained by some areas getting more rain than others.

The latest data continues to show growth rates increasing, but farms with average farm covers above 2,050 kg DM/ha generally continue to outperform those with lower covers.

There are some exceptions. On some farms, average cover is above 2,000 kg DM/ha but growth rates remain low. This is often because there has been only limited rainfall. For example, on a farm I visited today, paddocks had greened up following rain and average cover had reached 2,150 kg DM/ha, with paddocks at the three-leaf stage. However, little rain had fallen after the first rain, meaning soil moisture was still limiting growth.

Why average farm cover matters in dry conditions

Maintaining average farm cover ahead of dry conditions requires action. This usually means slowing the round and supplementing early.

Extending the round allows plants to reach the three-leaf stage, maximising their growth potential and that of the grazing platform.

As dry conditions continue, the three-leaf stage may only correspond to a cover of around 2,200 kg DM/ha. However, this grass can still be grazed. At this point, the plant has achieved its maximum yield and quality potential, while also allowing roots and plants to recover fully from the previous grazing.

This recovery is important because it puts the plant in the best possible position to respond when rain returns.

The difference between well-managed and poorly managed average farm cover can mean a delay of two to three weeks in returning to full grazing after a drought.

Reflecting on the summer

It may be worth taking some time to think about how you managed the dry summer.

Think not only about forage growth and resilience, but also about:

• The impact of high temperatures on cows
• Milk production
• Fertility
• Body condition
• Farm profitability
• How you and your team coped

Consider what went well and why, what didn’t go so well and why, and what will you do in the future to reduce the impact of hot, dry weather.

With climate extremes becoming more common, the conditions of 2026 could be the norm.

Nitrogen use this autumn

If your farm is within a Nitrate Vulnerable Zone (NVZ), obey the rules.

For farms outside NVZs, the decision to apply nitrogen depends on your grazing and feed requirements.

If cows will be housed during October and growth rates are already good, there may be little benefit from additional nitrogen. However, if you intend to graze into early December, there may be a case for applying nitrogen after the first post-drought grazing rotation.

Nitrogen needs to be used responsibly, both environmentally and financially.

Although days are getting shorter and it’s cooling down, soils are warm, and there’s still potential to grow dry matter.

As a guide:

• Growth rates of 10 kg DM/ha/day will give 5 kg DM per 1 kg of nitrogen applied, with full response taking 10 to14 weeks
• Growth rates of 20 to 40 kg DM/ha/day will give 10 kg DM per 1 kg of nitrogen applied, with full response taking 6 to 8 weeks
• Growth rates of 50 to 70 kg DM/ha/day will give 15 kg DM per 1 kg of nitrogen applied, with full response taking 5 to 6 weeks

These figures are based on good quality ryegrass swards. Responses are likely to be lower in older pastures with significant weed grass content. At this stage of the season, growth rates of  50 to 70 kg DM/ha/day are becoming less likely (DairyNZ Managing Nitrogen Fertiliser Use).

Ultimately, nitrogen can still provide a return in some situations. The key questions are: what feed do you need, and how does your farm generally perform at this time of year?

A final thank you

This will be my last Forage for Knowledge commentary as I move on to pastures new.

Having been involved with Forage for Knowledge since it began in 2009, I would like to thank all farms that have contributed. Without your contribution, this quality national data would not be possible.

Thank you also to everyone at AHDB who has supported and funded the programme, and to all the people who have been involved over the years. From Helen, who came up with the name Forage for Knowledge, to Emily, who wrote for the newsletter in the early years, and Debbie and Emily, who have since managed and expanded the programme.

Finally, thanks to you all for reading.

Looking ahead

Forage for Knowledge will be back in two weeks, with comments from my fellow Pasture to Profit Consultant Bess Neil.

If you don’t know Bess, she has been consulting on grass and forage-based systems for a long time and very successfully. Over to you, Bess, and thank you.