Posts Tagged ‘Bala Tikkisetty’

Precious soil being lost to the ocean – but should we focus more on fish than farmers?

Andy Loader, co-chairman of the Primary Land Users Group, has challenged information in an article, by Bala Tikkisetty, Sustainable agriculture co-ordinator for the Waikato Regional Council, published in the New Zealand Herald in mid-December.

The article (HERE) said more must be done to stop the slide of soil into waterways and, ultimately, the ocean.

“It makes economic sense to do so and also helps better protect our waterways and aquatic life from the effects of sedimentation.

“The scale of this loss of a farmer’s most precious resource is huge in this country.

“We lose it to the ocean about 10 times faster than the rest of the world, with between 200 million and 300 million tonnes sliding into the sea every year.”

New Zealand’s total land area is just less than 268,000 square kilometres. The top estimate implies we will lose the total land area of New Zealand to a depth of 1 metre over the next hundred years – roughly – from this soil erosion.

Mr Loader (see HERE) notes the article does not mention the effects of pest fishes on the scale of the erosion problem, particularly in the Waikato and Waipa River catchments.

According to Mr Loader’s estimates, there are approximately 500,000 tonnes of Koi Carp alone in this area. These produce about 14 times their own bodyweight of sediment per year (seven million tonnes), by their feeding method.

Where do the regional council figures come from, he asks, because “they seem excessive to me?”

The article by Bala Tikkisetty also states:

Waikato Regional Council staff can advise on best practice at individual sites. The council also has funding (up to 70 per cent of costs) available to help farmers in priority susceptible west coast and Waipa catchments to carry out erosion control and other land management activities.

Funding covers:

– tree planting, including pole planting and native plant species

– fencing off marginal land or bush from active use

– riparian management (fencing, planting and stock water reticulation)

– farm plans to identify soils, land use capability and environmental projects.

Mr Loader says it is great to see the council doing something practical to improve the water quality in the catchments, but

“… the fact of the matter is that the majority of the waterways around farms are already fenced and further fencing will not have a huge effect on improving water quality unlike other issues.”

He wants the council to provide funding to remove pest fishes from these catchments.

“Surely with the pest fishes creating so much sediment in the waterways as well as the other environmental damage that they do, their removal would achieve huge improvements very rapidly.”

Many people are unaware of the damage done to our waterways by pest fish, Mr Loader contends. But introduced fish have spread into the wild, become pests and are threatening New Zealand’s freshwater species and environments by:

• Stirring up sediment and making the water murky

• Increasing nutrient levels and algal concentrations

• Contributing to erosion

• Feeding on and removing aquatic plants

• Preying on invertebrates, native fish and their eggs

• Competing with native species

Mr Loader agrees with much of what the article says, but questions why it seems to single out farming as a main contributor to the effects of erosion when there are other causes such as natural water courses, urban development and vegetation removal outside of farming.

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Good soils are at the heart of agricultural enterprise in the Waikato

Waikato Regional Council’s soil quality monitoring programme measures soil properties such as soil compaction, nutrient status, biological activity, soil carbon and organic matter at 152 sites, with about 30 sites sampled annually. The sites cover a range of soils supporting various land uses.

The main soil quality issues identified are compaction, excessive phosphorous and nitrogen (N) on dairy and cropping land, and declining carbon, mainly on cropping land, says Bala Tikkisetty, a sustainable agriculture advisor at the council.

The good news is that some of the emerging data trends suggest there is an improvement in some soil quality indicators, most likely the result of good land management practices undertaken by our farming community, he says.

But some measures in various areas are still causing concern, with improvements needed.

That’s because minimising human-induced soil erosion and maintaining good soil quality are essential for maintaining so-called soil “ecosystem services”, such as nutrient and water buffering, productive capacity, assimilating waste, and minimising impacts of sediment and other contaminants on water bodies.

The transformation of so-called “natural capital” – namely soil, plants and animals, air and water into resources that people value and use – is at the heart of what’s meant when we refer to ecosystem services.

The concept is gaining more attention nationally as we see environmental pressure increasingly applied to resources, such as soil health, that we once took for granted.

Tikkisetty says the several practices which help support and improve soils and provide clear benefits include:

• avoiding over grazing and heavy grazing in wet weather (leading to compaction)

• avoiding under or over-fertilisation

• appropriate use of pesticides and other agrochemicals

• managing pasture to maintain complete soil cover

• careful application of farm dairy effluent to optimise organic matter and avoid saturation .

There is also benefit in protecting on-farm wetlands, which deliver a wide range of ecosystem services, such as improving water quality, flood regulation, coastal protection, and providing recreational opportunities and fish habitat.

A suite of tools called functional land management seeks to optimise the agronomic and environmental returns from land and relies on the multi-functionality of soils. It focuses on soil functions that are specifically related to agricultural land use, Tikkisetty says  They are:

• primary production

• water purification and regulation

• carbon cycling and storage

• functional and intrinsic biodiversity

• nutrient cycling

New research is focussed on nutrient cycling in soil, such as the ability of soils to recycle N, carbon and phosphorus and how this can best be managed.

To reduce N leaching from soils, Tikkisetty says, the research is seeking to understand mechanisms for N retention in soil and how to manipulate soil processes to enhance de-nitrification. As soil microbes are the key agents for nutrient cycling, scientists are focussing on determining the impacts of soil management on soil microbial activity.

He says the Waikato Regional Council is strongly committed to working with the wider farming community to increase the understanding of soil ecosystems services and ways in which farmers can manage them both to benefit their business, and to protect or enhance the natural capital on which it is based.

This work has already resulted in production of the menus of practices to improve water quality. They identify farming solutions and provide assessments of their effectiveness in managing various contaminants from farm land. The online version of the menus can be found atwww.farmmenus.org.nz.

The council will be keeping a close eye on the new research and providing advice to the farming community when we know more.

Bala Tikkisetty can be contacted on 0800 800 401 or bala.tikkisetty@waikatoregion.govt.nz.