Monday, February 26, 2024

Looking for the high ground in NZ soil carbon survey 

Avatar photo
Rural Land Co keen to learn its numbers as first round of national carbon sampling nears completion.
As a requirement of the act, LINZ staff are making more regular inspections of pastoral lessees. File photo
Reading Time: 2 minutes

NZX-listed New Zealand Rural Land Company’s co-founder is hoping the results of a nationwide carbon survey his company is participating in will open the door to greater debate on carbon’s value in storing agri-greenhouse gases.

The company has two dairy farms in its 12,000 hectare pastoral portfolio included in the national carbon survey being conducted by Manaaki Whenua – Landcare Research, which is close to completing its first round of carbon sampling from Cape Reinga to Bluff.

Typically, NZ’s younger, less-cultivated soils have been regarded as being relatively high in carbon levels, with research showing increasing those levels can be achieved incrementally at best.

NZ Rural Land co-founder Richard Milsom said the company is keen to view results from the survey as soon as possible to get a handle on where its farms’ particular carbon levels lie. 

“It has proven an opportunity for us to be an active rather than passive participant in the survey. It starts with sampling,  and we are aiming to implement some of the results in our enduring land for life programme, on the bleeding edge rather than being a slow follower.”
The soil carbon survey is measuring soil carbon on 500 pastoral sites across NZ and is concluding its first sampling round. The first sites were sampled almost six years ago and are about to be re-sampled. 

Early results have revealed few surprises for scientists, with the anticipated levels of lower carbon tending to show up in crop land, rather than on perennial pasture country.

Landcare scientists are hopeful the survey will provide some indicators on movements in carbon amounts across the different pastoral sectors nationally.

Milsom said NZ’s understanding about the ability to sequester carbon below ground in the soil rather than above ground in trees is still in the relatively early stages. The survey will do much to improve that understanding.

“It is a case of having soil versus dirt. In United States where there is heavy mono-cultural cropping there has been a heavy loss of carbon and loss of soil structure. Here, with largely pasture-based and low re-grassing rates, we have soils mineralised for longer.”

The two NZ Rural Land properties are dairy units totalling almost 1000ha. One is Toi Puke in Otago and the other Browns in Southland.

Milsom said he hopes the good management of the two properties will reflect in their carbon levels, with minimal pugging and careful cropping management helping keep levels up.

Regenerative agricultural practices have been hailed as a means of lifting soil carbon levels, but Milsom shied away from a wholesale adoption of the phrase in NZ Rural Land’s operations.

“What is sometimes called normal practice for us here in NZ may be seen as revolutionary in some other countries. There are a number of hypotheses about regen that are up to interpretation, but we are keen to be data- and science-driven with our decision making.”
As NZ again revisits its Emissions Trading Scheme policies, Milsom said anything learnt from the survey results could be useful in getting recognition of soil’s ability to sequester carbon.

“Part of our farm environment plans are to sequester greenhouse gases, and anywhere you can sequester it should be identified.”

He said he hopes NZ Rural Land will be leading from the front in setting an example of how to better understand, manage and improve soil carbon levels for other landowners.

People are also reading