Our round-up of the latest research from institutions and universities across the globe looks at how Australian scientists are using sound to repair degraded soils. Elsewhere, Brazilian researchers have unveiled a new biodegradable sensor to detect pesticides on fruit or vegetables. Scroll through the gallery for more…
Image: Getty/PM Images
Our round-up of the latest research from institutions and universities across the globe looks at how Australian scientists are using sound to repair degraded soils. Elsewhere, Brazilian researchers have unveiled a new biodegradable sensor to detect pesticides on fruit or vegetables. Scroll through the gallery for more…
Image: Getty/PM Images
It is estimated that around 75% of soils around the world are degraded. Scientists in Australia hope to repair them with sound. Researchers at Finders University in Adelaide investigated the effects of acoustic stimulation on fungal biomass and organic matter decomposition – both crucial components of ecosystem functioning. They also assessed the effect of acoustic stimulation on the growth rate and sporulation of the plant growth-promoting fungus Trichoderma harzianum.
The team played 70 dB and 90 dB soundscape treatments (at 8 kHz) to teabags in compost in for eight hours per day for 14 days to test whether acoustic stimulation affected fungal biomass and organic matter decomposition.
They also played a monotone soundscape (80 dB @ 8 kHz) over five days to Trichoderma harzianum to assess whether this stimulation affected the growth rate and sporulation of this fungus (control samples received only ambient sound stimulation <30 dB).
The results revealed that acoustic stimulation treatments resulted in increased fungal biomass, greater decomposition, and enhanced T. harzianum conidia (spore) activity.
“These results indicate that acoustic stimulation influences soil fungal growth and potentially facilitates their functioning,” wrote Jake Robinson, a restoration ecologist who specialises in ecoacoustics at Finders University in Adelaide, who led the study. “Our study highlights the potential of acoustic stimulation to alter important functional soil components, which could, with further development, be harnessed to aid ecosystem restoration.
Image: Getty/Andreas Häuslbetz
A five-year study conducted at 106 sites in eight European countries revealed that the use of approved pesticides in European agricultural landscapes still negatively affects non-target organisms, such as bees. This significantly reduces the colony performance of bumble bees: a key wild and commercial pollinator. The study, published in the journal Nature, said sustainability goals are needed to reduce pesticide use and risk.
Professor Mark Brown from Royal Holloway said: “The scale of this work provides a step-change in our understanding of the impact of agrochemicals on pollinator health, but we need to act now. A strong, and governmentally supported move towards integrated pest management in agricultural systems across the globe, resulting in a reduction in pesticide use, would dramatically improve the health of wild pollinators, and broader biodiversity.”
Image: Getty/Nigel Harris
Researchers at the University of São Paulo and the Federal University of Viçosa in Brazil have developed a sensor that can be placed directly on the surface of a vegetable or fruit to detect the presence of pesticides.
Known for this reason as “plant-wearable”, it is made of cellulose acetate, a material derived from wood pulp.
The device has the potential to help assure food safety in a world that increasingly suffers from a shortage of food and the environmental and health problems caused by excessive use of agrochemicals.
An article describing the results of the study is published in the journal Biomaterials Advances.
Pesticides are widely used to raise crop yields and are typically applied by spraying, but only 50% reach their target. The rest ends up in soil, groundwater, surface water, raw drinking water, wastewater and food products. Monitoring of pesticide levels in water, soil and food is therefore essential to prevent contact between these toxic substances and the public via the skin, lungs or digestive system.
The analytical tools most often used for this purpose are chromatographic techniques, which are effective but have drawbacks such as the need for pretreatment of samples, expensive equipment and qualified laboratory specialists, as well as the long-time taken to complete the analysis and lack of portability. The unsafe residues produced by organic solvents are also a significant problem under present-day conditions.
“As an alternative, electrochemical sensors can combine affordability, rapid detection, miniaturization, large-scale production, convenience, ease of use, high selectivity and in situ pesticide detection. Our invention has all these features. The analysis is performed directly on the surface of fruit, vegetables or leaves. Hence the term plant-wearable,” said Paulo Augusto Raymundo-Pereira, author of the article and a researcher at the São Carlos Physics Institute in Sao Paulo.
“However, instead of the usual materials, which are environmentally unsustainable and take a long time to degrade, such as ceramics or plastic polymers derived from petroleum, we used cellulose acetate, a material derived from plants that has little impact on the environment and disintegrates completely in 340 days or less depending on local conditions. Of course, it has to have appropriate characteristics for any sensor, including low cost, portability and flexibility.”
The study also investigated whether washing and immersing vegetables in a litre of water for two hours was effective to remove pesticide residues. The results showed removal of 40% of the carbendazim and 60% of the paraquat from lettuce, and 64% of both from tomatoes.
“Washing and immersion were clearly insufficient to remove residues of the pesticides. At least 10% remained in the leaves or peel,” Raymundo-Pereira said.
The technology can be useful for sanitary surveillance agencies worldwide, he added, as well as sellers of organic produce to certify absence of pesticides. Farmers generally can use it to monitor levels of pesticides in the field and be sure of applying only the requisite dose to each crop or part of a plantation. Pesticide use could decrease as a result, while yields will still rise, leading to lower consumer prices.
Image: Electrochemical sensors can combine affordability, rapid detection, miniaturization, convenience, ease of use, high selectivity and in situ pesticide detection. Credit: Paulo Augusto Raymundo Pereira
In warm and humid regions, the fungus "Magnaporthe oryzae", or rice blast fungus, has become a serious threat to wheat production since it was first observed in 1985. It initially spread from Brazil to neighbouring countries. The first cases outside of South America occurred in Bangladesh in 2016 and in Zambia in 2018. Researchers from Germany, Mexico, Bangladesh, the USA and Brazil have now modelled for the first time how wheat blast will spread in the future.
According to the research, South America, southern Africa and Asia will be the regions most affected by the future spread of the disease. Up to 75% of the area under wheat cultivation in Africa and South America could be at risk in the future. According to the predictions, wheat blast will also continue to spread in countries that were previously only slightly impacted, including Argentina, Zambia and Bangladesh. The fungus is also penetrating countries that were previously untouched. These include Uruguay, Central America, the south-eastern USA, East Africa, India and eastern Australia. According to the model, the risk is low in Europe and East Asia - with the exception of Italy, southern France, Spain and the warm and humid regions of south-east China. Conversely, where climate change leads to drier conditions with more frequent periods of heat above 35 °C, the risk of wheat blast may also decrease. However, in these cases, heat stress decreases the yield potential.
Image: Getty/HS3RUS
A new computational framework provides a detailed assessment of ammonia emissions from global croplands and identifies practices that could curb release of the gas.
Croplands are the largest single source of atmospheric ammonia, emitted from fields treated with nitrogen fertiliser. Ammonia can harm human health, acidify soil and waterways and contribute to biodiversity loss, food insecurity and climate change. However, the international study as detailed in Nature, found that emissions could be cut by 38% without altering total fertiliser inputs.
Jiafu Mao, a scientist at the Oak Ridge National Laboratory in Tennessee, helped devise a machine learning approach to improve ammonia emission estimates from wheat, corn and rice fields. The model enabled the identification of local best practices that could mitigate emissions, even in a warming climate.
“This valuable model, backed by artificial intelligence tools, can also fine-tune biogeochemical cycling and greenhouse gas emissions in the Department of Energy’s Earth system model,” Mao said.
Image: Getty/Sjo
Scientists are aiming to unlock the potential of clover and other legumes to reduce the use of fertiliser and emissions from livestock agriculture, thanks to a £3.3 million UK government grant.
To achieve the government net zero targets by 2050, greenhouse gas emissions from livestock farming need to fall by 78% by 2035. At the same time, the world’s population is forecast to reach 10 billion people by 2050, with demand for food predicted to rise by 70%.
UK sheep and cattle production relies predominately on grass-based pastures which use chemical nitrogen fertiliser to grow the grass used as feed for these livestock. Currently the process of manufacturing one tonne of chemical nitrogen fertiliser can release up to eight tonnes of carbon dioxide.
Clovers and other legumes can ‘fix’ their own nitrogen from the atmosphere and can share this with grasses growing in the same field.
As part of a new UK government funded project in partnership with industry, scientists at IBERS, a research institute at Aberystwyth University, will look at the ability of red and white clover and another legume, Birdsfoot Trefoil, to improve the productivity of livestock whilst reducing reliance on chemical nitrogen fertiliser.
New legume varieties have been developed by Germinal and Aberystwyth University that are more resilient to grazing by cattle and sheep and extreme weather, due to climate change. Birdsfoot trefoil contains compounds called tannins, which can reduce methane emissions by cattle and sheep.
Researchers will be working with commercial farmers in the ‘NUE-Leg’ project to maximise its benefits. The project will look at how to best take advantage of the natural ability of legumes to fix nitrogen, reducing reliance on chemical nitrogen fertilisers.
The research will include on-farm trials to identify how to support farmers to reach net zero targets.
Dr Christina Marley from IBERS at Aberystwyth University said:
“This project could really help cut the use of fertilisers and agricultural emissions. The aim is to make the most of the ability of clovers and other legumes to increase nitrogen levels naturally in UK grasslands. We are really looking forward to working together with livestock farmers to understand how best to use these new legumes within real farming systems. There is so much potential in these adaptations to some of our native plants, as we, as a society, undertake a wider collective effort to tackle climate change”.
A new study shows that plants use their circadian clocks to regulate responses to changes in water and salinity, offering a new avenue for creating drought-resistant crops.
Researchers at California’s Keck School of Medicine of USC found that plants use their circadian clocks to respond to changes in external water and salt levels throughout the day. That same circuitry—an elegant feedback loop controlled by a protein known as ABF3—also helps plants adapt to extreme conditions such as drought.
“The bottom line is plants are stuck in place. They can’t run around and grab a drink of water. They can’t move into the shade when they want to or away from soil that has excess salt. Because of that, they’ve evolved to use their circadian clocks to exquisitely measure and adapt to their environment,” said the study’s senior author, Steve A. Kay.
The findings point to two new approaches that may help boost crop resilience. For one, agricultural breeders can search and select for naturally occurring genetic diversity in the circadian ABF3 circuit that gives plants a slight edge in responding to water and salinity stress. Even a small increase in resilience could substantially improve crop yield on a large scale.
Kay and his colleagues also plan to explore a genetic modification approach, using CRISPR to engineer genes that promote ABF3 in order to design highly drought-resistant plants.
“This could be a significant breakthrough in thinking about how to modulate crop plants to be more drought resistant,” Kay said.
Image: Getty/wildpixel
