Soil C stocks in grains and sugar farming systems

Quantify soil C stocks in grains and sugarcane cropping systems of Queensland, including impacts of management practices.

Innovative management of herbicide resistant weeds - seed banks and soil biology

The project will evaluate seed bank depletion of key northern herbicide resistant weeds under different environments, cropping systems, crop agronomies and non-chemical control tactics. The project will also evaluate soil biology and seed bank relationships to explain differences in seed bank persistence.

Crop sequences to manage soil pathogens and increase northern grain production

This is part of a GRDC funded project led by Dr Jeremy Whish of CSIRO Ecosystem Sciences. The project aims to build a root-lesion nematode module into the crop growth simulation program APSIM (Agricultural Production Systems Simulator). This will utilise existing nematode and crop data from field, glasshouse and laboratory research led by Dr John Thompson. New data will be collected to validate and extend the model.

National soil health consortium

Work with Land and Water Australia to coordinate soil health work across Queensland and Australia.

Declining soil phosphorus reserves on sustainable agricultural production systems

PhD scholarship investigating the relative sensitivity of nitrogen fixation in adapted grain and ley legume species to low soil phosphorus.

DAQ00049 Farming Systems for Central Queensalnd Soil Research and Monitoring

Sustainable Farming Systems for Central Queensland.

QPI64 Sustainable Soil Health Management Workshop Northern Broadacre Cropping Industries

Workshops to increase participants understanding and knowledge by farm businesses and healthy catchments farmers about the role of soil health in supporting sustainable through variable circumstances, farm businesses and healthy catchments.

Influence of soil organic amendments on suppression of the burrowing nematode, Radopholus similis, on the growth of bananas.

Radopholus similis is a major constraint to banana production in Australia and growers have relied on nematicides to manage production losses. The use of organic amendments is one method that may reduce the need for nematicides, but there is limited knowledge of the influence of organic amendments on endo-migratory nematodes, such as R. similis. Nine different amendments, namely, mill mud, mill ash, biosolids, municipal waste compost, banana residue, grass hay, legume hay, molasses and calcium silicate were applied to the three major soil types of the wet tropics region used for banana production. The nutrient content of the amendments was also determined. Banana plants were inoculated with R. similis and grown in the soil-amendment mix for 12-weeks in a glasshouse experiment. Assessments of plant growth, plant-parasitic nematodes and soil nematode community characteristics were made at the termination of the experiment. Significant suppression of plant-parasitic nematodes occurred in soils amended with legume hay, grass hay, banana residue and mill mud relative to untreated soil. These amendments were found to have the highest N and C content. The application of banana residue and mill mud significantly increased shoot dry weight at the termination of the experiment relative to untreated soil. Furthermore, the applications of banana residue, grass hay, mill mud and municipal waste compost increased the potential for suppression of plant-parasitic nematodes through antagonistic activity. The application of amendments that are high in C and N appeared to be able to induce suppression of plant-parasitic nematodes in bananas, by developing a more favourable environment for antagonistic organisms.

Organic inputs, tillage and rotation practices influence soil health and suppressiveness to soilborne pests and pathogens of ginger.

A field experiment was established in which an amendment of poultry manure and sawdust (200 t/ha) was incorporated into some plots but not others and then a permanent pasture or a sequence of biomass-producing crops was grown with and without tillage, with all biomass being returned to the soil. After 4 years, soil C levels were highest in amended plots, particularly those that had been cropped using minimum tillage, and lowest in non-amended and fallowed plots, regardless of how they had been tilled. When ginger was planted, symphylans caused severe damage to all treatments, indicating that cropping, tillage and organic matter management practices commonly used to improve soil health are not necessarily effective for all crops or soils. During the rotational phase of the experiment, the development of suppressiveness to three key pathogens of ginger was monitored using bioassays. Results for root-knot nematode (Meloidogyne javanica) indicated that for the first 2 years, amended soil was more suppressive than non-amended soil from the same cropping and tillage treatment, whereas under pasture, the amendment only enhanced suppressiveness in the first year. Suppressiveness was generally associated with higher C levels and enhanced biological activity (as measured by the rate of fluorescein diacetate (FDA) hydrolysis and numbers of free-living nematodes). Reduced tillage also enhanced suppressiveness, as gall ratings and egg counts in the second and third years were usually significantly lower in cropped soils under minimum rather than conventional tillage. Additionally, soil that was not disturbed during the process of setting up bioassays was more suppressive than soil which had been gently mixed by hand. Results of bioassays with Fusarium oxysporum f. sp. zingiberi were too inconsistent to draw firm conclusions, but the severity of fusarium yellows was generally higher in fumigated fallow soil than in other treatments, with soil management practices having little impact on disease severity. With regard to Pythium myriotylum, biological factors capable of reducing rhizome rot were present, but were not effective enough to suppress the disease under environmental conditions that were ideal for disease development.

Ultrafast Raman loss spectroscopy: a new approach to vibrational structure determination

The rapid data acquisition, natural fluorescence rejection and experimental ease are the advantages of the ultra-fast Raman loss scattering (URLS) which makes it a unique and valuable molecular structure-determining technique. URLS is an analogue of stimulated Raman scattering (SRS) but far more sensitive than SRS. It involves the interaction of two laser sources, viz. a picosecond (ps) pulse and white light, with the sample leading to the generation of loss signal on the higher energy (blue) side with respect to the wavelength of the ps pulse, unlike the gain signal observed on the red side in SRS. These loss signals are at least 1.5 times more intense than the SRS signals. Also, the very prerequisite of the experimental protocol for signal detection to be on the higher energy side by design eliminates the interference from fluorescence, which always appears on the red side. Unlike coherent anti-Stokes Raman scattering, URLS signals are not precluded by non-resonant background under resonance condition and also being a self-phase matched process, it is experimentally easier.

Protein A: nature's universal anti-antibody

Staphylococcal protein A specifically interacts with immunogobulins. This fact is being used in various disciplines of biology and some of the unique properties of protein A and their applications are summarized in this review.

Banana root and soil health user’s manual: FR02023 Soil and root health for sustainable banana production.

This manual identifies simple, practical tests to measure soil health and outlines the use of an on-farm testing kit to perform these tests. This testing is designed so that banana producers or agricultural consultants can asses or monitor the health of the soil inexpensively and without the need for a laboratory.

Soil carbon stock in the tropical rangelands of Australia: Effects of soil type and grazing pressure, and determination of sampling requirement.

On-going, high-profile public debate about climate change has focussed attention on how to monitor the soil organic carbon stock (C(s)) of rangelands (savannas). Unfortunately, optimal sampling of the rangelands for baseline C(s) - the critical first step towards efficient monitoring - has received relatively little attention to date. Moreover, in the rangelands of tropical Australia relatively little is known about how C(s) is influenced by the practice of cattle grazing. To address these issues we used linear mixed models to: (i) unravel how grazing pressure (over a 12-year period) and soil type have affected C(s) and the stable carbon isotope ratio of soil organic carbon (delta(13)C) (a measure of the relative contributions of C(3) and C(4) vegetation to C(s)); (ii) examine the spatial covariation of C(s) and delta(13)C; and, (iii) explore the amount of soil sampling required to adequately determine baseline C(s). Modelling was done in the context of the material coordinate system for the soil profile, therefore the depths reported, while conventional, are only nominal. Linear mixed models revealed that soil type and grazing pressure interacted to influence C(s) to a depth of 0.3 m in the profile. At a depth of 0.5 m there was no effect of grazing on C(s), but the soil type effect on C(s) was significant. Soil type influenced delta(13)C to a soil depth of 0.5 m but there was no effect of grazing at any depth examined. The linear mixed model also revealed the strong negative correlation of C(s) with delta(13)C, particularly to a depth of 0.1 m in the soil profile. This suggested that increased C(s) at the study site was associated with increased input of C from C(3) trees and shrubs relative to the C(4) perennial grasses; as the latter form the bulk of the cattle diet, we contend that C sequestration may be negatively correlated with forage production. Our baseline C(s) sampling recommendation for cattle-grazing properties of the tropical rangelands of Australia is to: (i) divide the property into units of apparently uniform soil type and grazing management; (ii) use stratified simple random sampling to spread at least 25 soil sampling locations about each unit, with at least two samples collected per stratum. This will be adequate to accurately estimate baseline mean C(s) to within 20% of the true mean, to a nominal depth of 0.3 m in the profile.

Multinomial solutions of the beach equation

Exact multinomial solutions of the beach equation for shallow water waves on a uniformly sloping beach are found and related to solution of the same equation found earlier by other investigators, using integral transform techniques. The use of these solutions for a general initialvalue problem for the equation under investigation is briefly discussed.