Better soils with Brett Petersen Kiwi Fertiliser & Golden Bay Dolomite

The government is calling for a reduction of the national dairy herd to reduce nitrogen and phosphate pollution of our water tables and waterways.

At the same time, they are denying carbon credits to farmers.

They should be consistent and financially recognise carbon increases in the soil. They do that for pine tree owners, but not farmers. That is a disgraceful and indefensible policy.

Artificial nitrogen applications decrease soil carbon. Reduction of N inputs must be rewarded with incentives, not punished by demonising farmers.

After all, they have been following government policies backed by so-called scientific findings for decades.

However, farmers can be rewarded by joining up with a New Zealand company called Verdi, www.verdi.nz. They will measure your carbon to 700mm deep and keep measurement data over a minimum of 10-years.

Some alteration to management may be required to maximise sequestration.

1. Minimising conventional soil disturbance practices. For example, ploughing, discing or mechanical tilling implements that may invert the soil strata are permitted only when necessary.

2. Limiting the application of synthetic fertilisers, especially nitrogen. Whenever possible apply synthetic N at levels that minimally impact soil health negatively – fewer than 12.5 units/ha/application. When practical, apply with a carbon source and apply as a foliar spray.

3. Avoid overgrazing and utilise adaptive grazing management practices that have shown to minimise losses of soil carbon stocks.

4. Increase pasture diversity. When establishing new pastures or reinvigorating old pastures, consider adding a multitude of different plant species from different plant families. This will increase crop resilience in adverse conditions, limiting carbon loss.

Using a 230ha dairy farm as an example, it has sequestered 435 tonnes of carbon per hectare over 10 years. After 10 years the owners may choose to sell some of those carbon credits for the current rate at date of sale. At $30/t, the total value of the carbon for that farm is $3 million.

Part of the credits are retained to allow for price and sequestration fluctuations. Sure, there are the annual costs of testing to account for, with the cost for the example farm being just over $5,000. A property of 600ha will cost twice as much to measure annually.

Irrespective of whether you are interested in carbon credits or not, the government is requiring N usage to be curtailed.

Many farmers may be wary of reducing N inputs on their farm. Kiwi Fertiliser www.kiwifertiliser.co.nz is involved with doing just that by employing the Total Replacement Therapy Program. See www.totalreplacementtherapy.com for more details.

There are eight steps to follow. The first one involves the financials. “Set up a production and financial comparative monitoring plan. Compare previous production and profitability to projected outcomes.”

Starting 14 years ago, the writer took dairy farms off N inputs, while increasing their profits - without carbon credits. Others in Kiwi Fertiliser have achieved similar results.

The lowest N input the writer managed was 3kg/ha of N, being nine units of N over one-third of the 500ha dairy unit. This was applied as a liquid where close to 100 per cent of the applied N is taken up by the plant with the assistance of humic acid - a carbon source.

These days, we fertilise properties where no nitrogen is applied. They are increasing their profitability, not decreasing it.