Nutritional strategies for dry and variable climates

Chris Dowling, Technical and Services Delivery Manager, Nutrient Management Systems

GRDC code
NMS00002 "Adoption of improved nutrient management by the Australian grains industry

“Australia's climate presents a challenge to agriculture as it seeks to become more profitable, competitive and sustainable. In an environment where 80% of farm profit may be made in 30% of years, and where inflexible management can lead to land degradation, hardship and poverty, the uncertainty of a variable climate presents both risk and opportunity.” (LWA 2008)

In thinking about this challenge, for the most part, recent approaches have been to try to manage crop nutrition based on better weather and climate forecasting. Clearly there have been significant advances in this technology recently with climate tools such as SOI and MJO, and crop management tools such as Whopper Cropper and Yield Prophet but for many focusing on weather and climate falls well short of what is desired.

An alternate approach could be to continue to use the climate tools but to also work on the soil “plastic” capacity. More than ever we need to have soils in condition that allows them to respond automatically to short-term change in production potential rather always needing quick management intervention.

As part of the broadly acknowledged “rundown” in soil fertility of the northern cropping belt, there has been a loss of nutrient supply plasticity, nutrient supply plasticity being the soils inherent capacity to automatically respond to changes in production potential. In a nutritional sense plasticity is mostly based in the organic matter for the majority of nutrients but for some it means maintaining the soil nutrient concentration close to a point where responses to fertiliser application are rarely seen.

In the northern cropping belt there are fewer nutrient management options than in other areas due to variability and low probability of rainfall at during some nutritionally important crop development windows. It is therefore more important to have the soil in a state where it is able to adjust where management option are limited.

How capable is your soil in responding to short term change; how do you know whether your soils will be able to help you?

The following steps are a guide to an emerging process for managing the soil resource including nutrients:

1. Conduct Soil Function Assessment
a. Identify management responsive and unresponsive soil properties, processes.
b. Audit current soil practices.
2. Reassess realistic production goals based on ability to manage limitations and/or manipulate properties and processes.
3. Develop and implement a mid to long-term nutrient management strategy (3- 5 year) aligned to manageable soil properties and processes.
4. Develop and implement SMART seasonal nutrient management tactics.

Contact details
Chris Dowling
Mb: 0407 692 251
Ph: 07 3821 3544
Email: cdowling@nutrientms.com.au