Theme 1: Integrated Soil Systems

The Integrated Soil Systems research program has a focus on soils as living systems that form the basis of both agricultural and environmental systems. 

The program uses fundamental investigation to interpret and assist full system level function, meaning that research conducted as the sub-micro scale is made relevant to landscape catchment function and management. Working with the other Centre for Sustainable Agricultural System research program teams, the Integrated Soil Systems RPT delivers management solutions limiting risk, and with a focus on optimising the full system, rather than system components. Considering soil as one of Australia’s greatest natural assets, the aim of the research program is to deliver outputs that provide both production and ecosystem outcomes from the same parcel of land, leading to sustainable and profitable outcomes. Within the Integrated Soil Systems research program there are a number core sub-programs, including:

  • Soil security for Australia
  • Soil structure and solute interactions
  • Conservation agriculture
  • Strategic soil constraint management
  • Land management and rehabilitation

Projects

Project Leader: John Bennett

Research Partner: Verterra |The Australian Coal Industry Research Program (ACARP)

ACARP Project C24033 developed a framework to support practical, cost-effective management of dispersive spoil through a package of costed, risk-based decision support tools and associated Best Management Practices (BMPs). In the process, the project developed an underlying model that is sufficiently robust to have application across all aspects of mine rehabilitation. Outcomes of Project C24033 have been compiled into a web-tool to provide easy access to the package of decision support tools and facilitate practical application of project results. However, to ensure widespread adoption across the mining sector, feedback has indicated value in providing extension of the model to industry practitioners. This would provide opportunity for further refinement of the model interface, functionality and underlying parameterisation through user driven feedback, continued evaluation of field trials and testing against validation sites. It will also assist transition of the model into common usage. This proposal extends ACARP Project C24033 from application to dispersive spoil, to widespread application across all mine rehabilitation situations, with the aim of simultaneous technology transfer and model refinement.

The objective of the project is to facilitate transfer of ACARP Project C24033 dispersive mine spoil rehabilitation outputs into practice and to refine the package of decision support tools through a combination of user-driven training and incorporation of results from operational rehabilitation to achieve improved rehabilitation outcomes. The project will also extend the application of the decision support tools to all mined land rehabilitation.

Project Leader: John Bennett

Research Partner: Soil CRC | Federation University

Data is key to sustainable soil health and profitable agriculture. Following on from the scoping study. A review of indicators of soil health and function: farmers’ needs and data management, this project addresses the issue of large amounts of underutilised agricultural data.

The aim of the project is to provide Australasian farmers, agronomy practitioners, agricultural researchers and agribusinesses with relevant place-based information on demand. It will improve soil data availability and encourage the generation of new research ideas, collaborations and investment, both locally and globally.

Project Leader: Afshin Ghahramani

Research Partner: Soil CRC, Southern Cross UniversityNSW Department of Primary Industries | Farmer groups across northern and southern region

Recently, cover crops are shown to be an effective to improve ground cover, increase water availability, and the yields of subsequent crops. Cover crop residues can enhance activities of soil microbial communities, respiration, and N mineralization. Hence, it is very important to investigate how managing cover crops can influence the soil biology in terms of soil biota and function, soil biological processes and their impacts on soil water holding capacity and the farm production. The significant advances that could be achievable in this research topic are to identify sub-soil profile characteristics during the fallow phase under cover crops and weeds management with respect to weather, biomass production and impact on soil moisture profiles in association with soil textural characteristics. This research will use experimental results of cover crop projects and will conduct field trials, modelling, and implication of artificial intelligence that will develop methodologies to predict sub-soil moisture across profile. 

Project Leader: John Bennett

Research Partner: TPC Ltd | New Hope Group | Santos Ltd

Data is key to sustainable soil health and profitable agriculture. Following on from the scoping study. A review of indicators of soil health and function: farmers’ needs and data management, this project addresses the issue of large amounts of underutilised agricultural data.

The aim of the project is to provide Australasian farmers, agronomy practitioners, agricultural researchers and agribusinesses with relevant place-based information on demand. It will improve soil data availability and encourage the generation of new research ideas, collaborations and investment, both locally and globally.

Project Leader: John Bennett

Research Partners: GRDC | University of New England | Queensland Government | Soil Management

This project seeks to facilitate growers with the confidence to employ amelioration approaches for soil constraints that will work within the farm operational and economic framework. The projects primary aim is to determine the “do nothing” management threshold for soil constraints; the point where investment in an amelioration approach does not make sense. This is a function of both the mechanistic and the economics. The major constraints of interest to this project (economic effect within the Northern Grains Region; GRDC 2017) are:

  1. Soil sodicity – affecting 8.1 million ha and costing growers $433 million / year;
  2. Soil compaction (one form of physical soil structural decline) – affecting 0.8 million ha and costing growers $37 million/yr;
  3. Soil acidity - affecting 1.5 million ha and costing growers $61 million/yr; and,
  4. Soil salinity - affecting 2.6 million ha and costing growers $47 million/yr.
Importantly, these constraints very rarely occur in isolation, rather, simultaneously. This means ameliorative action plans must consider the interacting nature of constraints, which encompasses the approach of this work for Australian grain growers.

Project Leader: John Bennett

Research Partners: Soil CRC | The University of Newcastle | NSW Department of Primary Industries

This project will harness recent advances in chemical engineering techniques and development of innovative organic based amendments to more effectively address subsoil constraints that affect many Australian agricultural soils. It will improve our understanding of the interactions of these novel products with different soil types and crops. The project will also address zone specific placement of amendments by using advanced formulations and application machinery. This project aims to develop a new generation of submicron organic-based amendments with the ultimate aim of correcting subsoil constraints and thereby increasing crop production.

Project Leader: Afshin Ghahramani

Research Partner: CSIRO, NQ Dry Tropics, Great Barrier Reef Foundation

The main objective of this study is to collect measured data that will support the anecdotal evidence that regenerative grazing practices lead to improved landscape function, runoff and water quality. Demonstrated benefits, established via sound scientific methods, will be beneficial to the land-owners, investors (LRF and Reef Credits) and the Banking sector. [Note that the specific metrics to be collected will be finalised after the initial literature review, however, the likely candidates are variables such as soil type and stability, carbon and organic matter content, litter, pasture cover and biomass, bulk density, soil nutrients such as N, P and C etc and well as runoff and water quality, TSS, TN where possible].

Project Leader: Afshin Ghahramani

Research Partner: GRDC | The University of Sydney | CSIRO | Australian National University| BoM

This project will deliver a scientific framework that can be used by digital agriculture companies and commercial third parties to nowcast plant available water (PAW) at any point in time, within and across paddocks and at multiple depths in the soil profile to aid growers with on-farm decision making. The approach will be agnostic to the type of soil water data streams and will be able to digest these to extract the best features of all in terms of accuracy and spatial and temporal resolution to provide improved predictions of PAW using scale-able, modular modelling frameworks that can be easily operationalised into new analytics products by commercial third-parties. The agnostic nature of the approach means that it will be future proof in terms of being able to accommodate the next generation of sensors, remote sensing platforms and water balance modelling approaches using a foundation of data layers that are freely available third-party IP but also being flexible enough to incorporate additive value generated from sources of commercial TIP. The project will test, develop and refine data-driven, data assimilation, hybrid soil water balance model and ensemble-based approaches (i.e. different analytical frameworks) to predicting PAW using the combined expertise of five different research organisations and strong collaborations with grower networks and industry, including the Society for Precision Agriculture in Australia.

 

Project Leader: John Bennett

Project Partners: CRDC | CSIRO | Soil Management

Australian crops are harvested with heavier machinery, increasing soil load and compaction risk throughout the rooting depth, with compaction known to cost >$30M to the Australian Cotton industry annually.  Soil type, tillage history, prior soil structural condition, and soil-moisture content at harvest all influence soil compaction. Soil compaction results in restricted crop growth, reduced nutrition and water use efficiency, increased waterlogging and reduced yield.

No simple technique exists that allows farmers to assess the impact of compaction, or to guide and inform the choice of appropriate remediation techniques. This project therefore seeks to quantify the merit of current techniques used to remediate compaction, and assess advantages/disadvantages of techniques used. There is a lag-time associated with soil compaction remediation and crop response, so the project will further focus on monitoring strategies used to manage and/or ameliorate compaction.

Sub-soil sodicity decreases rooting depth and increased irrigation frequency, with an annual cost to Australian agriculture of >$1.3B, due to decline in soil structure and water infiltration. As the cotton industry expands across new regions with diverse soils, the likelihood of sodicity occurrence may increase. Amelioration of sodicity is through application of calcium, which is costly to address sub-soil constraints. This work will consider sodicity and compaction independently and in interaction, identifying where amelioration is viable and where adaptive management is more economically feasible.

The project will utilise an applied field-methodology to quantify management approaches in terms of soil health and economics, as well as inform economic and numerical decision management tools, allowing for long-term compaction and sodicity management option assessment.