Management systems for enhanced nutrient availability
Theme 2: Nutrient management
Research projects under this theme are focused on addressing one or more of the following questions/issues:
• Can molecular tools provide the transformational knowledge required to identify the major and minor biological players in critical nutrient transfer processes?
• How can the plant-soil system be managed to enhance N immobilisation when plant demand is low and enhance N mineralisation when plant demand is high?
• How can soil biology be manipulated to either reduce P fixation or to enhance release from the soil matrix?
• Can nutrient capture and release processes that occur at the plant root soil interface be upscaled to the agro-ecological zone?
Theme 2 projects include:
• Harnessing the nitrogen cycle through novel solutions (GRDC project code UWA0013)
• Managing soil biology to improve nitrogen supply in grain production systems (DAV00106)
• Manipulating biological processes that improve nitrogen supply to cereal crops: Free-living nitrogen-fixing bacteria (CSP00138)
• Assessing management options for enhanced soil phosphorus availability using rotations (UA00119)
Bacteria could supply nitrogen for free(Ground Cover Issue 96 Supplement)
Free-living and endophytic nitrogen-fixing bacteria can provide crops with free nitrogen, without the need to form symbiotic relationships. However, the lack of ability to quantify the value of these non-symbiotic bacteria has meant that their nitrogen contribution is not considered when calculating nitrogen requirements.
Novel solutions to harness nitrogen (Ground Cover Issue 96 Supplement)
Nitrogen is a primary nutrient regulator of plant productivity. There have been many studies on the availability of nitrogen from the soil, crop residues and fertilisers. Yet as recently as 2007, carbon availability was established as the key to processes that cause nitrogen to be lost from the system.
Biological release of P from the soil bank (Ground Cover Issue 96 Supplement)
Phosphorus is typically applied at seeding to ensure adequate crop production. Of the phosphorus fertiliser applied, less than 30 per cent is taken up by the current crop. In economic terms, this is equivalent to Australian grain growers each year burying $5-$10 billion dollars in their paddocks.
Nitrogen transformation in agricultural systems (Ground Cover Issue 96 Supplement)
Nitrogen is vital for grain yield and quality, yet the efficiency of nitrogen fertiliser use by the current year’s crop is often less than 50 per cent. The key to improving nitrogen use efficiency is to better synchronise nitrogen supply, from both fertiliser and soil sources, with crop demand. To achieve this, better understanding is required of the soil biological and chemical factors governing nitrogen transformations in agricultural systems.
Monitoring soil quality for better decision making
Suppressive soils - traits and transferability