Herbicide runoff reduced to Great Barrier Reef

Oct 16, 2013
Spraying raised beds only – shielded sprayer is covering the furrows.

(Phys.org) —An innovative new approach to sugarcane plantation weed management trialled in select Great Barrier Reef (GBR) catchments has shown a 90 per cent reduction in runoff of highly soluble herbicides into waterways.

In the lower Burdekin region of northern Australia, scientists from CSIRO's Water for a Healthy Country Flagship trialled a new technique for applying herbicides to raised beds of furrow irrigated sugar cane by using a specially adapted shielded sprayer. The technique minimises the likelihood of herbicides such as diuron, atrazine, ametryn and hexazinone coming into contact with .

Many of the herbicides used in the region are PSII herbicides that are known to negatively impact reef ecosystems. These waters discharge into the internationally recognised Great Barrier Reef World Heritage Area and subsequently into the Great Barrier Reef Marine Park. Improved farming techniques such as the shielded sprayer help keep herbicides on-farm have potential to have a significant and positive impact on in the GBR.

"The conventional application of herbicides in furrow-irrigated sugarcane production is to broadcast spray across the whole field using boom sprayers, which applies herbicides to both beds and furrows. Irrigation water then carries the herbicides with the tail water into the drainage channels, into nearby creeks and rivers and potentially into the GBR lagoon," CSIRO research leader, Dr Rai Kookana said.

"Given the importance of improving GBR water quality additional testing and demonstration of these technologies across different soil types, farming systems - and possibly with different combinations of chemicals - would provide valuable additional testing of the approach from an industry perspective."

"These trial results are extremely encouraging, and clearly demonstrate that the use of precision herbicide application technologies by the industry, including using shielded sprayers for furrow-irrigated sugarcane cultivation, can be highly effective in reducing herbicide run-off."

CSIRO scientist Danni Oliver said the geography of the region meant that almost the entire flow from the Burdekin River Irrigation Area in the (from July to January) was made up exclusively of irrigation water from sugarcane and other cropping.

"The trials show that while there will certainly be some loss following the first irrigation or rainfall event, the marked decreases in losses documented in this study – a reduction of to 90 per cent - could lead to significant improvements in off-site water quality, particularly during the dry season," Ms Oliver said.

According to Jon Brodie of James Cook University the amount of some herbicides in creek and estuarine waters during this period regularly exceeds Australian water quality guidelines and could potentially affect, for example, coastal seagrass.

The results of the study have been published in the international journal Science of the Total Environment.

Explore further: US delays decision on Keystone pipeline project

More information: Oliver, D. et al. 2013. Banded applications are highly effective in minimising herbicide migration from furrow-irrigated sugar cane, Science of the Total Environment, 466–467 (2014) 841–848. www.sciencedirect.com/science/article/pii/S0048969713009017

add to favorites email to friend print save as pdf

Related Stories

Herbicide-tolerant crops can improve water quality

Apr 22, 2008

The residual herbicides commonly used in the production of corn and soybean are frequently detected in rivers, streams, and reservoirs at concentrations that exceed drinking water standards in areas where these crops are ...

Researchers study pesticide pathways into the atmosphere

Jul 12, 2011

When soil moisture levels increase, pesticide losses to the atmosphere through volatilization also rise. In one long-term field study, U.S. Department of Agriculture (USDA) scientists found that herbicide volatilization ...

How grass buffers keep agricultural herbicides at bay

Apr 26, 2010

Grass buffer strips are commonly used in crop production to reduce herbicide runoff. These practices are encouraged through incentives, regulations or laws, and are effective at lowering herbicide concentration ...

'Superweeds' linked to rising herbicide use in GM crops

Oct 02, 2012

A study published this week by Washington State University research professor Charles Benbrook finds that the use of herbicides in the production of three genetically modified herbicide-tolerant crops—cotton, soybeans and ...

Recommended for you

US delays decision on Keystone pipeline project

Apr 18, 2014

The United States announced Friday a fresh delay on a final decision regarding a controversial Canada to US oil pipeline, saying more time was needed to carry out a review.

New research on Earth's carbon budget

Apr 18, 2014

(Phys.org) —Results from a research project involving scientists from the Desert Research Institute have generated new findings surrounding some of the unknowns of changes in climate and the degree to which ...

User comments : 0

More news stories

China says massive area of its soil polluted

A huge area of China's soil covering more than twice the size of Spain is estimated to be polluted, the government said Thursday, announcing findings of a survey previously kept secret.

UN weather agency warns of 'El Nino' this year

The UN weather agency Tuesday warned there was a good chance of an "El Nino" climate phenomenon in the Pacific Ocean this year, bringing droughts and heavy rainfall to the rest of the world.