Fertiliser reduction becomes a real option for wheat growers research findings indicate

Termed as the High NUFER method it has been proven across seven years of research to produce high grain yield and protein content for wheat

Calling for extended local research are Dr Mark Sweetingham, farmer Daniel Birch, UWA Professor Wallace Cowling, farmer Rod Birch and Hackett Professor Kadambot Siddique – Image: UWA

A method that determines the ideal fertiliser application for wheat crops – without sacrificing yield or protein content – has been proven to reduce fertiliser input requirement, decrease greenhouse gas emissions and increase net income for grain growers.

The Director of The University of Western Australia’s Institute of Agriculture Hackett Professor Kadambot Siddique confirmed the results from a seven-year research project he contributed to, that was led by scientists from Northwest A&F University in China.

The study had the aim to produce high grain yield and protein content for wheat production in China using a High Nutrient-Use Efficiency Based Fertiliser Recommendation (High NUFER) method.

According to the Bankwest Curtin Economics Centre, Western Australian farmers increased their use of fertiliser fourfold between 1990 and 2018.

Fertiliser was also the main source of WA farm costs at approximately 18%.

Similarly in China, fertiliser use increased by 511% from 1978 to 2019, with grain production increasing by only 118% in the same period. Levels of fertiliser use that cannot be sustained.

Hackett Professor Kadambot Siddique says there is an immediate to reduce fertiliser and return the balanced – Image: UWA

China is the world’s largest producer and user of fertilisers, with numerous reports of fertiliser overuse.

Although chemical fertiliser application is key to ensuring high and stable crop production, Professor Siddique said excessive fertilisation reduced fertiliser efficiency and farm economic benefits and caused various environmental problems.

“Over-applied fertilisation has been shown to cause excessive nitrate-N in water, eutrophication and greenhouse gas emissions that threaten drinking water quality and environmental safety,” he said.

“This study provides scientific guidance for saving costs, increasing farm income and improving sustainable agricultural development in China and other countries in similar situations, such as Australia.”

For the study, the research team conducted farm surveys covering 1,575 paddocks in 17 of China’s major wheat production provinces from 2015 to 2019.

The on-farm information included wheat planting area, varieties, paddock management, soil nutrient status and fertilisation status. Wheat plant and soil samples were also collected from farmers’ paddocks for measurement and analysis.

From 2020 to 2021, the researchers verified the High NUFER method in 46 sites across seven major wheat production provinces.

Producing high grain yield and protein content wheat crops is still possible to achieve with lower levels of fertiliser by using the High NUFER method – Image: UWA

Professor Siddique said the validation experiments in the final year of the study proved that fertilisers were over-applied and often imbalanced.

“It revealed that the recommended fertiliser application based on High NUFER reduced nitrogen and phosphorus fertiliser use without affecting grain yield and protein content, relative to the farmer’s previous fertilisation application,” he said.

“The reduced fertiliser improved the partial productivity of nitrogen and phosphorous fertiliser and alleviated soil available potassium depletion.

“With the High NUFER method, grain growers can reduce their fertiliser input, thereby increasing economic benefits and decreasing greenhouse gas emissions. Similar studies are urgently needed in Australia and other wheat-growing countries, with the involvement of relevant farmer groups.”

All with the obvious aim to reduce fertiliser input levels, but still maintain high grain yield and protein content for wheat production using the High NUFER method.