Archive for the ‘Environment’ Category

World-leading sensors to guide action against contamination of waterways

AgResearch reports it has developed world-leading sensors to better understand how nitrogen is being excreted by cows, and therefore how best to tackle the impacts on the environment.

The urine sensors, which have been a work in progress since 2010, are attached to grazing dairy cows and take detailed measurements every time the cow urinates, including volume and frequency – and crucially the concentration of nitrogen in the urine that can potentially leach into soil and waterways, and can cause damage such as algal blooms.

A recent Colmar Brunton poll found pollution of lakes and rivers to be one of the top two concerns for New Zealanders, but there is now promising research underway to address the challenges for water quality such as nitrogen leaching.

AgResearch senior scientist Dr Brendon Welten says the benefit of the urine sensors is a much greater understanding of the behaviour of the cows, which can help develop techniques to mitigate the nitrogen leaching from farms.

“Other sensors exist around the world to provide data from livestock, but these sensors we’ve developed are unique in their ability to record nitrogen concentrations each time the cow urinates during grazing,” Dr Welten says.

“We can learn, for example, how different species of pasture affect the amount of nitrogen excreted in urine.”

The sensors weigh about 1.5 kg, and attach to the cow by a harness connected to a lightweight cow cover. They record the data through the use of multiple instruments (temperature, pressure and refractive index), with data stored in a data logger that can be remotely accessed via a wireless network system.

The sensors have already been used in both the United Kingdom and Australia.

“The operation of the sensors is complex, and at this stage we are working towards offering the sensors to other researchers around the world to allow them to use the technology to make similar gains,” Dr Welten says.

“AgResearch will have the expertise to support those researchers to use the technology and maximise the benefits from it.”

The sensors have played a part in important progress made in the Forages for Reduced Nitrate Leaching (FRNL) programme* – involving DairyNZ, AgResearch, Plant & Food Research, Lincoln University, the Foundation for Arable Research and Manaaki Whenua (Landcare Research).

DairyNZ senior scientist Ina Pinxterhuis says the FRNL results clearly confirm the variability in urinary nitrogen excretion over the day, making it necessary to have many repeated measures. The sensors make this possible.

He says “it is great to see that the options we examine to reduce nitrate leaching do result in lower daily urinary nitrogen excretion and lower nitrogen concentration – if not during the whole 24 hours of the day, at least for some parts’.

The information provides new options for management too.


Phosphorus pollution is found to be dangerously high in global freshwater

Uh, oh. Something else for environmental policy-makers to address and farmers to  remedy. Phosphorous pollution.

But good science will be needed to ensure the right decisions are made.

According to a media release from the American Geophysical Union, a new study has found man-made phosphorus pollution is reaching dangerously high levels in freshwater basins around the world.

The study published in Water Resources Research, a journal of the American Geophysical Union, estimated the global amount of phosphorus from human activities that entered Earth’s freshwater bodies from 2002 to 2010.

Phosphorus is a common component of mineral and manure fertilizers because it boosts crop yields but a large portion of the phosphorus applied as fertilizer is not taken up by plants. It either builds up in the soil or washes into rivers, lakes and coastal seas, according to the study’s authors.

The results of the new study show global human activity emitted 1.47 teragrams (1.62 million US tons) of phosphorus per year into the world’s major freshwater basins, four times greater than the weight of the Empire State Building.

The study also assessed whether human activity had surpassed the Earth’s ability to dilute and assimilate excess levels of phosphorus in fresh water bodies. The authors found phosphorus load exceeded the assimilation capacity of freshwater bodies in 38 percent of Earth’s land surface, an area housing 90 percent of the global human population.

“In many areas of the world either there’s not enough water to assimilate the phosphorus or the pollution load is so huge that the water system can’t assimilate everything,” said Mesfin Mekonnen, a post-doctoral research associate at the University of Nebraska in Lincoln and co-author of the new study.

The study’s results indicate freshwater bodies in areas with high water pollution levels are likely to suffer from eutrophication, or an excess level of nutrients, due to high phosphorus levels, said Joep Schyns, a researcher in the field of water management at the University of Twente in Enschede, the Netherlands, who was not connected to the new study.

“Eutrophication due to phosphorus pollution causes algal blooms, which can lead to the mortality of fish and plants due to lack of oxygen and light,” Schyns said. “It also reduces the use of the water for human purposes such as consumption and swimming.”

The authors of the new study examined agricultural activity to calculate the total amount of man-made phosphorus entering Earth’s surface water from 2002 to 2010. They gathered data on how much fertilizer is applied per crop in each country, and estimated domestic and industrial phosphorus production by looking at protein consumption per capita per country.

“Other studies have calculated global phosphorus loads, but we went farther because we broke down the phosphorus load by various categories such as different crops, countries, and economic sectors, which no one has done,” Mekonnen said.

The new results show China contributed 30 percent of the freshwater phosphorus load, followed by India at 8 percent and the USA at 7 percent.

The largest contribution to the global Phosphorus load came from domestic sewage at 54 percent, followed by agriculture at 38 percent and industry at 8 percent.

The authors found the phosphorus load from agriculture grew by 27 percent over the study period, from 525 gigagrams (579,000 US tons) in 2002 to 666 gigagrams (734,000 US tons) in 2010.

The study also estimated the water pollution level (WPL) of Earth’s major river basins by comparing the amount of fresh water needed to dilute the excess phosphorus to an allowable concentration compared to the basin’s actual river runoff. If a freshwater basin has a WPL above one, water quality standards are being violated and the basin is receiving more phosphorus pollution than it can assimilate, Mekonnen said.

The results show freshwater basins with a WPL above one cover 38 percent of Earth’s land surface, excluding Antarctica. These basins often pertain to densely populated areas or regions with intensive agriculture, according to the authors.

The most severely polluted freshwater areas include Aral drainage basin, the Huang-He (Yellow) river in China, the Indus and Ganges rivers in India and the Danube river in Europe.

Less-populated regions such as Australia and northern Africa also suffer from high water pollution levels, according to the study. These regions have smaller phosphorus loads compared to areas like China and Europe, but they have much less water available to accommodate their excess phosphorus.

New nitrate detection technology could save waterways

Technology being developed at the University of Canterbury (UC) could revolutionise nitrate monitoring in waterways, the university has announced in a press release (HERE).

The novel electrochemical sensing system offers the advantages of selectivity and high sensitivity, and when fully developed will also have long life and durability.

Once the system is fully developed, furthermore, it will be able to send information wirelessly, doing away with manual field sampling and lengthy and expensive laboratory testing.

The electrode is geared to work in waterways such as streams, groundwater, aquifers and estuaries.

Nitrate levels could be measured and electronically sent to regional councils –
for example – providing real-time information on waterways across catchment areas.

Or a manager at a mussel farm could be alerted when nitrate concentrations are too high, so workers could adjust or ameliorate the environment before harm is done to the product.

Associate Professor Vladimir Golovko and Associate Professor Aaron Marshall have collaborated on projects at UC for about eight years. Associate Professor Golovko, a chemist, provides expertise in catalytic metal particles (nanomaterials which can be synthesised using chemical techniques) while Associate Professor Marshall, an engineer, orks on the electro-chemistry side.

The research team identified nitrates as a significant issue for New Zealand, looked at existing technology, and identified a gap in the market for a low-cost and reliable sensor.

This research has earned them one of five prizes in UC’s annual Tech Jumpstart competition, which awards $20,000 over six months to take innovative research towards commercial reality.

Associate Professor Marshall says many countries have similar problems with run-off from farms or over-fertilisation.

“This has huge potential for New Zealand and worldwide,” he says.

“The prize allows us access to market analysis and look at where we might get further funding. These things are critical in moving the project from its early stage to the next level where we can operate outside lab conditions and take environmental samples in the field.”

The next step would be to make the hardware prototypes and an app that will deliver the readings.

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.

Gauging what must be done to make US beef production environmentally sustainable

Americans would have to halve the amount of beef they eat each week to make the American beef industry environmentally sustainable, according to a team of researchers.

The authors have designed a model for sustainable production where cattle are raised only on grass, hay and food industry by-products. This would free up 32 million hectares of cropland currently used to grow food for cows that could be used to grow crops for humans.

They say their model would reduce the amount of fertiliser and water needed, as well as reducing greenhouse emissions. However, their model produces just under half of the beef the US currently does.

A media release from Springer Nature says a model for the more sustainable supply of up to 45% of current US beef consumption is presented in a paper published online in Nature Ecology & Evolution. (see HERE).

The US beef industry is often cited as a major greenhouse gas contributor, not only from the cattle themselves, but also from the fodder grown to feed them.

Gidon Eshel, Ron Milo and colleagues have defined sustainable beef production as cattle that are raised on grassland (pasture and small amounts of locally baled hay) and food industry by-products, such as distillers’ grains or sugar-beet pulp.

The authors’ model finds that, using this definition of sustainable beef production, an estimated 32 million hectares of cropland currently used to grow fodder could be reallocated for plant-based food production.

The authors suggest  this reallocation would also dramatically reduce nitrogen fertilizer and irrigation water use while substantially reducing greenhouse gas emissions. They find combining the change in land use with pasturing could lead to 45% of current beef production being sustainable.

In addition, they find that halving the size of existing pastureland used (to about 135 million ha), by abandoning less productive grasslands, can still sustainably deliver 43% of current production.

Finally, they show that a reduction in beef consumption from the current level of about 460 g per person per week to about 200 g per person per week could make the entire US beef industry environmentally sustainable (by the narrow definition of the paper).

The authors emphasise that this is just one possible model and definition of sustainability, and caution that any model must maintain protein needs.

Due to the very low feed-to-food protein conversion efficiency of beef, however, reallocating feed land to all considered plant alternatives at least maintains protein supply, and reallocation to such protein-rich plants as soybean, for example, increases protein production from the land five-fold.

EPA report says NZ has its share of science deniers

The global phenomenon of science denial and scepticism about the role of experts is alive and well in New Zealand, the Environmental Protection Authority says in its 2016/17 annual report.

Opposition to bureaucracy and scepticism about scientific endeavour and the role of experts are highlighted in the report as key pressures facing environmental regulators around the world.

“New Zealand has its share of science deniers whose opinions are reinforced and nurtured in the unmoderated milieu of the internet,” says the report.

“Protecting the environment does not mean building a wall around it or immunising it from change.

“Environments are dynamic, always evolving, and the threats to them are ever-changing. We must find a balance among competing pressures in the search for a better New Zealand.

“Our decisions matter. Though they do not always meet with universal favour, our role is to work within the law and make decisions based on facts, data and science, using the expertise of our high-skilled scientific and technical staff.”

The report covers a range of activities, including:

– The reclassification of 200 hazardous substances as part of an ongoing review of New Zealand’s chemical landscape to ensure risks to people and the environment are adequately managed

– Helping kiwi families stay safe around household chemical products through a public information campaign and Facebook page that had 93,000 hits in its first year

– Working alongside Australian regulators to promote coherent regulatory practice and policy, and prioritising the formulation of consistent regulation across both countries

– Development of a Red Alert system to raise public awareness about the dangers of certain chemicals

– A nationwide series of territorial authority workshops addressing system-wide approaches to managing hazardous substances to protect local environments and communities

– Strengthening scientific leadership through the appointment of a chief scientist

– Supporting New Zealand’s obligations under international treaties and agreements, for example the UN Framework Convention on Climate Change

– Providing logistical support to the decision-making process for Trans-Tasman Resources marine consent and marine discharge applications and two Proposals of National Significance – Auckland’s Northern Corridor and East West Link.

EPA chief executive Allan Freeth said 2016/2017 had been a year of executing the agency’s vision to be a proactive regulator, to anticipate and lead change.

New programme promotes profitability and sustainability

Improving environmental, economic and social outcomes are at the heart of an expansive new sustainability science programme from Plant & Food Research.

The Sustainable Agro-Ecosystems programme (SAE) is an initiative that prioritises scientific research specifically aimed at enhancing the productivity and resilience of the primary industries while also reducing environmental footprint.

The projects within the programme sit under three key research themes: Land Use Suitability, Plants for the Environment, and Future Farming.

The overarching objective is to deliver scientific knowledge, tools and technologies that simultaneously improve the quality of our environment, increase profitability, grow export earnings, and improve market access, says Plant & Food Research Team Leader Steve Thomas.

“Achieving this means the smart and sustainable use of resources, such as soil, nutrients and water; and taking into account the ever growing complexity of the economic, social and cultural environment that farmers and growers now operate in.

“The impact of farming on our environment is under increasing scrutiny, yet the pressure to produce high-value products and be profitable is as great as ever. There is also the need to consider and adapt to the implications of a changing climate and to reduce greenhouse gas emissions.”

The programme is aimed at enabling New Zealand farmers and growers to sustainably produce high-value crops with the smallest environmental footprint possible.

It is envisaged that this research will support the establishment of enhanced, environmentally considered crop management systems that will ultimately deliver greater value and performance.