Ammoniated straw incorporation improves wheat production and soil fertility

An international team of researchers, including from The University of Western Australia’s Institute of Agriculture, have determined that ammoniated straw incorporation (ASI) treatment significantly improves wheat crop production and soil fertility.

ASI is a process by which ammonia is added to stubbles/straw, which degrades the lignin and enhances nutrients for it to be more easily broken down by soil microbes.

The research, published in the journal Field Crops Research and led by Northwest A&F University in China, investigated the responses of soil properties, wheat yield and yield stability of wheat to ammoniated and conventional straw incorporation in the China’s Loess Plateau.

The three treatments applied in the study were straw (the control), conventional straw incorporation (CSI), and ASI.

Averaged across the three years, the ASI treatment had significantly higher soil water storage, grain yield and yield stability compared to the CSI and control treatments.

Image: Standing and slashed wheat stubble in the field. Credit - Getty Images

The ASI treatment increased wheat yield by 10.1 per cent and yield stability by 19.5 per cent compared to the CSI treatment.

Changes in wheat yield and yield stability were positively related to ASI-induced increases in soil water storage in the dryland environment of Loess Plateau.

When compared to the CSI treatment, the ASI treatment increased soil organic carbon (SOC) content by 14.2 per cent and total nitrogen (TN) content by 18.3 per cent in 0–10 cm depth, and increased SOC content by 12.4 per cent and TN content by 19.4 per cent in 10–20 cm depth.

The UWA Institute of Agriculture Director Hackett Professor Kadambot Siddique, who is a co-author of the paper, said ASI treatment was a very promising option for targeting sustainable agriculture in the dryland cropping regions of Australia.

Professor Siddique said the results provided clear and strong evidence that ASI could achieve higher grain yield and yield stability while increasing organic carbon and total nitrogen content in the soil.

However, he noted that the underlying mechanisms – particularly the microbial mechanisms— were largely unclear at the study site.

“This opens the door for future research opportunities,” he said.

“Investigating the environmental effects, such as greenhouse gases emissions and nitrogen leaching, are required before applying this knowledge to large areas.”