Dr Gordon Rajendram: War, Crisis and Why Clover Matters More Than Ever

New Zealand Soil Scientist

Global conflict is once again exposing just how vulnerable New Zealand farming systems are to international supply chains. Rising fuel prices, disrupted shipping routes, and instability in key fertiliser-producing regions are driving up the cost of transport and nitrogen fertilisers such as urea. These are costs farmers cannot control, yet they directly impact farm profitability.

We have been here before. The difference now is that we have better knowledge and proven systems that show we do not need to rely so heavily on imported nitrogen.

A Canterbury case study I was involved in clearly demonstrated this. A large-scale dairy operation reduced nitrogen inputs from 290–300 kg N/ha/year down to under 190 kg N/ha/year, while also cutting phosphate use from 45 kg/ha to 15 kg/ha annually. At the same time, pasture production still reached up to 19 tonnes of dry matter per hectare and milk production wasn’t compromised.

The key was not applying more fertiliser, but improving soil pH and soil biology, nutrient balance, and clover performance.

Clover is central to this discussion. It is not just another pasture species, it is a natural nitrogen factory. Research has shown white clover can fix anywhere from 20 kg to as much as 400 kg N/ha/year in grazed systems, but under ideal conditions, 250-350 kg consistently is possible and even higher. That nitrogen is effectively free, produced in the paddock, and available to drive pasture growth without the cost of urea.

At the same time, clover is one of the highest-quality feeds available. With protein levels of around 34 percent compared to approximately 19 percent in ryegrass, it delivers significantly more nutritional value to livestock. Higher energy, higher protein, and better mineral content, including calcium, all contribute to improved animal performance.

“One of the first things I look at is what the pasture looks like and how much white clover is in it.”

This translates directly into production. Research consistently shows higher liveweight gain and increased milk yield from cows grazing clover-rich pastures due to higher intake and better feed efficiency. Simply put, more clover means more milk.

However, excessive nitrogen fertiliser works against this system. Once nitrogen applications exceed around 200 kg N/ha/year, clover fixation declines sharply, and at very high rates it can stop altogether. Farmers then become locked into a cycle of dependency on purchased fertiliser, exactly the risk we are seeing play out today with global price volatility.

As I often say, “The more nitrogen you grow biologically through clover, the less you need to buy, and the more resilient your farming system becomes.”

The message is clear. In a world of rising costs and uncertainty, clover offers a proven pathway to reduce input costs, improve pasture quality, and lift milk production. It fixes the nitrogen problem naturally, efficiently, and economically.

Global events may be out of our control, but how we manage our soils and pastures is not.

“Any fool can grow rye glass but it takes a real farmer to grow clover.” – Emeritus Professor Walker

For more information, contact:
Dr Gordon Rajendram
� 021 466077
✉️ rajendram@xtra.co.nz
� www.gordonrajendramsoilscientist.co.nz

Media Enquiries:
Media PA – Phillip
� 027 458 7724
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