Balancing soil health, productivity, and fertiliser on farms

Nutrient management is critical to promote crop health and productivity. Synthetic fertilisers have been heavily used to sustain sugarcane yields but applying too much can have big impacts on the environment. Over the last decade, more growers have explored alternative methods to improve soil health while reducing standard fertiliser application amounts.

Using rotational cropping, such as legumes, can help replace the soil nutrients while reducing the reliance on synthetic fertilisers. Multispecies cropping can enhance soil health and structure, prevent erosion and surface runoff, and manage nutrient leaching through cover crops with diverse root systems.

Limited research has been done on the benefits of multispecies cropping for commercial sugarcane farming in Australia. Field trials are needed in our region to assess how this approach can improve soil health, biodiversity, and greenhouse gas emissions while maintaining sugarcane yields.

Trialling the benefits of multispecies cropping

We are running trials of multispecies cover cropping at eight sugarcane farms across northern Queensland and New South Wales to measure the effects on crop productivity, soil health, and biodiversity. We will test different rates of nitrogen fertiliser application across the trials.

We are:

• Measuring crop productivity throughout crop cycles, using biomass and yield assessments.

• Tracking vegetation growth and nutrient uptake, using remote sensing and field surveys.

• Comparing nitrous oxide and methane emissions, using gas collection chambers.

• Assessing pollinator and soil microbial biodiversity, using environmental DNA (eDNA).

• Measuring bird biodiversity, using acoustic recording.

• Measuring overall resource consumption, using lifecycle impact assessment.

These measures will give a comprehensive assessment of how multispecies cover cropping in sugarcane could affect nitrogen retention, greenhouse gas emissions, and biodiversity.

Supporting scalable, sustainable nutrient management

This project is supporting growers seeking sustainable approaches to nutrient management by providing robust, real-world data on the benefits of multispecies cropping across major Australian sugarcane regions.

The project also aligns with programs such as the Queensland Government Reef Credit Scheme, evaluating potential economic benefits for growers adopting regenerative practices.

Participating growers and industry networks will share experiences from the cropping trials through workshops and factsheets, providing practical guidance for growers and supporting broader adoption across the sugarcane sector.

Project details

This project is led by Queensland Cane Agriculture & Renewables (QCAR), Lawrence DiBella from Tropical Agricultural Services, and independent grower and advisor Robert Quirk, with Dr Adam Canning from JCU TropWATER leading the scientific design and assessments. The project is funded by the Bonsucro Impact Fund.