Family affair

Long family history with lime

You could say lime runs deep in Greer Manderson’s bones.

His grandfather Jim started the Avoca lime business in Whangarei just after World War II and his father Bryce still runs it. Manderson, 22, has had a few seasons with Avoca and his younger brother Hamish also works there.

However, his attention has now turned to the science of lime. After graduating with a BSc (Biological and Environmental Sciences) at the University of Canterbury with Honors in Lincoln, she feels lime has become overlooked as a soil conditioner and nutrient.

Manderson did part of his study on the contribution of lime in controlling soil acidity, its impact on legumes (with specific reference to white clover or alfalfa) and the role that liming should play in the context of New Zealand soils.

She wants to examine the effects and benefits of liming, especially as its use appears to be declining in New Zealand. After finishing her final term of college, Manderson is now looking to pursue a career as a soil ecologist.

Her interest may have started being part of a lime mining family, but it all sparked in early 2020 after her dad Bryce flew out to take her to a presentation by Dr Christine Jones. . This internationally renowned and highly respected land cover and soil ecologist has spent much of her life working with innovative landowners, implementing regenerative land management practices that improve soil health and subsequent functioning of ecosystems, eg biodiversity, productivity, water quality.

The fact that lime is a natural product and can contribute to regenerative practices lit the fuse for her.

“My big interest is supporting regenerative agriculture,” she says.

Manderson explains how the main purpose of lime applied in New Zealand is to reduce soil acidity – and in the process – to add calcium to the soil, an essential nutrient for plants.

“I was raised knowing its importance. Now I am passionate about spreading the message that lime is a natural substance, extracted from the ground,” she adds. “It all starts in the ground.”

Manderson begins working this year with Canterbury-based regenerative agriculture advocate and consultant Jono Frew.

You can bet the lime benefits will show up from time to time. It’s in his bones.

New Association

Bryce Manderson worked with the Aggregate and Quarrying Association to start a New Zealand Limestone Producers Association to help promote the use of limestone and provide information on the benefits of its use.

Limestone producers across the country have formed a new national organization to represent their interests and refocus farmers on the critical need for lime in New Zealand pastures.

Shaun Cleverley is the first president of the NZ Limestone Producers Association, which will operate as a division of the Aggregate and Quarrying Association, AQA.

He says it makes sense for the lime industry to pool resources and work together.

“The driving force is that approximately 70-80% of our ad spend is dedicated to promoting the use of aglime, rather than our particular product over a competitor’s.

“The opportunity for our industry is to now have a body to produce and coordinate much of the content and science, which many users have done alone, often simultaneously.”

Limestone quarries produce around 10% of all material mined in New Zealand. Cleverley says production and sales have been reasonably constant in recent years, but farming has intensified, requiring more inputs, including aglime.

He says there is a direct correlation between the growth of grass or crops and the need for agricultural lime.

“Each farm will have a pH correction component required, relative to their production.”

Part of the discourse of the new organization is that lime is a natural product, coming from the earth.