Feed aggregator

Tasmania's grand plans to spend $3 billion on pumped hydro and new links to become the "renewable battery" of Australia may be undone by the plunging cost of battery storage.

The world just passed another round-numbered climate milestone. Scientists predicted it would happen this year and lo and behold, it has.

Tesla mobile app update allows Powerwall owners to monitor and manage their solar and battery storage “power flow”.

New paper looks at the barriers to deploying multiple terawatts of solar PV and what can be done to overcome them.

Farmers are turning to natural bacteria to improve crops like cane – but they might be getting rubbish. Gavin Fordham/Flickr

Australian farmers are at risk of missing out on a global boom in “crop probiotics”, because lax regulations make it less likely the supplements they buy to boost their crops will actually work.

Similar to the probiotics that offer health benefits for humans, certain natural bacteria can make crops healthier, hardier and more productive, by increasing their resilience to pests, pathogens and environmental stresses and improving access to soil nutrients.

But our research has found that the quality of products sold as “biostimulants” in Australia (which includes crop probiotics) varies wildly, with many available that do not deliver the promised benefits.

This potentially deprives our farmers of genuine products developed and tested with scientific principles. It muddies the waters, as companies selling effective products compete with those peddling “snake oil”. It also raises concerns about biosafety: importers can simply tick a few boxes and claim there aren’t pathogens in the bottle, without hard proof.

How do crop probiotics work?

Bacterial biostimulants naturally form a mutually beneficial bond with plants. One of the better known examples involves legumes, like clover and soybeans, which have rhizobia bacteria living in their roots. Rhizobia absorb nitrogen from air and deliver it as a natural fertiliser to their plant host in a symbiotic exchange.

As well as helping the plants thrive, farmers can use legumes to replenish nitrogen in soil, reducing the use of man-made nitrogen fertiliser. This symbiosis has been researched for over a century, and is well understood.

While we know less about other crop-beneficial bacteria, our understanding is growing. Microbes have been found that make crops more resistant to heat, waterlogging, drought and certain diseases.

But although the effects have been studied extensively in laboratories, it’s a big step to translate fundamental science to farm-relevant application.

Many factors, including the particular crop, soil and climate, influence the effectiveness of crop probiotics. The bacteria must survive transport and storage, and have to associate effectively with crops in the presence of many potentially competing microbes.

The communication between beneficial bacteria and crops is finicky as both partners have to produce mutually understandable chemical signals. We listened in on the conversation between beneficial Burkholderia bacteria and sugarcane, confirming that both undergo complex change to accommodate the partnership.

Finding the right microbes and making them work with crops in field settings remains difficult. Each group of useful microbes has many species and subtypes, and only few generally convey benefits, and often only in certain situations. Scientists are working to address these constraints.

Bold claims, inconsistent results

While crop probiotics offer an ecologically friendly option for farmers looking to improve and protect their harvests, the Australian market is far from reliable.

Our research group was asked to evaluate commercial crop probiotics. Over a year of experimentation on a sugarcane farm, we tracked the supposedly beneficial bacteria and fungi of two Australian probiotics products from soil to crop.

DNA analysis didn’t detect changes in root-associated bacteria, but the composition of root-associated fungi changed. Whether these changes are meaningful is unclear, as the manufacturers didn’t specify how the products work and which changes are to be expected. Clearly, studies over multiple years and sites are needed to confirm if and when products are beneficial.

The problem isn’t that biostimulants don’t work in principle. Many laboratory experiments have shown bacteria can help plants grow faster, stronger and bigger. But the real world is messy, with plenty of variables. Manufacturers who aren’t pushed by legislation can take shortcuts, and nebulous marketing is common.

Soybean root nodules, containing billions of nitrogen-fixing rhizobia. via Wikimedia commons

Our second investigation involved a commercial seedling nursery. The international manufacturer of the probiotic didn’t provide instructions for dosage, leaving us to guess at the correct application rate. In the first round of experimentation, the seedlings died. Feedback from the manufacturer was quick: we had used the wrong dose.

The next round of research used a lower dosage, per the manufacturer’s advice, that did not improve seedling growth. In its absurdity, this example highlights the need for tighter market regulation.

Since the benefits of currently available biostimulants are imprecise, many people are divided on their use. Better regulations would promote certainty, and prevent farmers wasting money on unreliable products.

The future of crop probiotics

Currently Australian regulations emphasise flexibility, offering multiple options for manufacturers to prove their crop probiotics work. But this leaves the door open for ineffective products.

Crop probiotics are currently regulated under the umbrella of pesticides (although they’re often marketed as providing other benefits). The Australian Pesticides and Veterinary Medicines Authority guidelines say “up to 10 field trials may be required depending on the crop’s economic importance”, making it difficult to tell how many trials are expected. One industry partner we spoke to said that, while he has chosen to do field trials, he didn’t have to supply that data to the APVMA to get his product registered.

Companies have to prove their products are “effective as per the label claims”. But as we found in our research, this doesn’t help when manufacturers exclude crucial information from their labels.

Manufacturers can sell probiotics that have been tested overseas, although studies “should be done under conditions that are typical of Australian climatic conditions”. However, because they’re not automatically required to retest in Australia, different soils, climates and crop types can render them essentially useless.

Consequently, many products exist on the Australian market which don’t have clear label instructions for effective use, claim to work on an outlandish number of crops and don’t even touch on the topic of which soils they work effectively in.

Australia contrasts with the European Union, which demands multi-step scientific testing of products. For a product to be permitted for use in agriculture, EU legislation requires 10 or more field trials, conducted over two growing seasons in different climates and soil types. Delivery methods and dosage must be evaluated and effects confirmed. Crop trials have to ensure statistical validity. The EU has created an online database of detailed reports and standards that can be easily searched by the public.

These regulations have an impact on which biostimulants reach the market. European products often contain only one type of active microbe, as it’s otherwise difficult to meet the strict criteria. On the other hand, many biostimulants sold in Australia contain multiple microbes that are not clearly classified on labels.

This makes it more difficult to tell what’s actually in a product, how useful it will be under different conditions, or if it contains bacteria that are beneficial for certain crops but harmful for others.

We recommend that Australia adopts the EU model of a regulated biostimulant market to encourage investment. Scientifically rigorous, multi-year studies are also needed, to test and develop effective products.

There is much research expertise in Australia, but currently farmers must rely on marketing rather than science.

Susanne Schmidt receives funding from industry and government including Sugar Research Australia and Queensland Department of Agriculture and Fisheries.

Shelby Berg receives funding from Sugar Research Australia.

Paul G. Dennis and Richard Brackin do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.

The engineer who proposed circular runways answers critics in defence of his radical design for airports.

Killer whale Takara was already pregnant when the end of the breeding programme was announced.

Just days after the death of 17 year old Laeticia Brouwer, a senate hearing in Perth has debated the merits of shark culling.

The government has secured green ‘commitments’ after the £2.3bn sale. In reality it has secured only ‘good intentions’

The charge that Macquarie is a ruthless asset-stripper that, given half a chance, would dismember the Green Investment Bank clearly stung. As the government unveiled the inevitable sale, for £2.3bn, to a consortium led by the Australian finance house, all sides were anxious to emphasise the buyer’s long-term enthusiasm for its new purchase.

GIB will survive as a discrete entity in Edinburgh. Macquarie will throw a few of its own assets – a couple of windfarms and a waste and biomass plant – into the mix for it to manage. It will report on progress in honouring GIB’s green investment principles. It will aim to invest £1bn a year in green energy projects, more than the £700m-ish that GIB was achieving via taxpayer funding. “We look forward to seeing these commitments from Macquarie delivered, in full, in the months and years ahead,” said Lord Smith of Kelvin, GIB’s chair.

Continue reading...

What's made this river in Canada disappear? Geoscientist Daniel Shugar explains.

Chris Packham has released the video that shows his encounter with a Maltese hunter and police on the island of Gozo, after being cleared of charges of assault by a Maltese judge on Thursday. The video shows Packham filming with his crew before being accosted by the hunter and police, leading to the incident. The judge threw out the case and criticised the police for the charge. Packham has said he will not press charges

• Chris Packham cleared of assault in Malta after confronting bird hunters
  

Continue reading...

Greenpeace says £2.3bn sale to controversial Australian bank Maquarie risks climate targets while Lib Dems says bank was sold too fast and too cheap

The UK government’s decision to sell the Green Investment Bank to Australian bank Macquarie for £2.3bn has been attacked by critics including the Liberal Democrats and Greenpeace as “politically dubious” and a “disaster”.

A consortium led by Macquarie, which also includes the bank’s European Infrastructure Fund 5 and the Universities Superannuation Scheme, a UK pension scheme for university professors, agreed to buy the GIB, established in 2012 by the coalition government to fund green infrastructure projects.

Continue reading...

Russia scales back staff on the ISS until a long-delayed space lab is sent to the outpost in 2018.

The latest study on the health benefits of cycling suggests it can cut the risk of cancer and heart disease. It’s also the most fun you can have on your daily commute

It may not be a surprise to see another study suggesting that cycling to work can drastically reduce your chances of getting cancer and heart disease – those who ride bikes for transport already know how good it makes them feel. However, it’s perhaps yet another motivation for those who don’t, to dust off their bikes – and remember some other reasons cycling to work is so great.

In a five-year study of 263,450 UK commuters, published in the BMJ, researchers at Glasgow University found regular cycling cut the risk of death from any cause by 41%, and the incidence of cancer and heart disease by 45% and 46% respectively.

Continue reading...

The Aral Sea was once the world's fourth largest inland body of water, it covered 62,000 square kilometres and a yearly commercial fishing catch of 42,000 tonnes.

Raised coastline could end the threat of sea erosion for the time being.

Think of Texas and it’s most likely you imagine rocky, red desert. But each spring the hill country of central Texas is awash with a riot of colour, as millions of wildflowers bloom

Continue reading...

Boris Behncke lives near Mount Etna and monitors the volcano.

The footprint made by a reptile that lived almost 250 million years ago has been found in the Pyrenees.

Scientists call for "amphibian arks" to protect wild salamanders in Europe from a deadly infection.