Summary

Land application of manure and spent litter can improve crop performance, carbon storage and soil quality but could also increase the risk of stable-fly (Stomoxys calcitrans) outbreaks, odour and greenhouse gas emissions (GHG). However, the true extent of their benefits and risks has not been fully evaluated or quantified. Moreover, stable fly outbreaks are becoming an increasing economic problem for the beef cattle and horse industries and rural communities of Western Australia (WA) through loss of land for grazing, recreational activities and tourism.
The aim of this project is to develop best management practices (e.g. application rate, spreading method and timing) for the land application of spent litter and to evaluate the effectiveness of a new biological control agent at reducing stable fly breeding. A series of laboratory and field experiments will be undertaken using adult fly emergence cages to identify and quantify fly development after the application of spent litter to a range of non-irrigated and broadacre farming systems. Additionally, the agronomic and economic benefits of the spent litter, in terms, of soil quality and crop productivity will be assessed.
The research outcome is the development of best management practices for land application of spent litter that decrease the risk of stable fly breeding whilst improving soil quality, crop productivity and profitability. This will enable the chicken meat industry to overcome environmental issues associated with litter disposal, gain community and planning support, develop new markets and revenue and increase production to meet expected growth in demand.

Program

Chicken Meat

Research Organisation

University of Western Australia

Objective Summary

The expected outcomes of the project are:
1.Better management options for spent litter treatment and disposal in areas of WA where stable fly breeding is an issue. Ensure that new methods align with developing litter management methodologies that mitigate GHG in soils
2.Better understanding of the benefits of amending soils with spent litter in terms of improvements to soil quality and crop productivity and quantification of their agronomic and economic value
3.Provide scientific evidence to help obtain both community and planning support and to develop new markets and opportunities for spent litter whilst protecting existing ones.

These outcomes will be achieved by the following objectives:
1.Determine the optimal spreading rate of spent litter to avoid stable-fly outbreaks
2.Evaluate the effectiveness of a new entomopathogenic fungi as a biological control agent for reducing stable fly breeding
3.Characterise the spent litter in terms of nutrient supply
4.Assess whether soil quality has been enhanced, sustained or reduced under different management options by measuring both microbial (microbial community profiling, quantitative PCR assays of beneficial microbes) and conventional (soil pH, water holding capacity, C:N ratio) indicators of soil quality
5.Use data obtained from objectives 3 and 4 to calculate the economic and agronomic value of spent litter. Prepare guidelines and factsheets on environmental sustainable use of spent litter as a soil improver for producers and growers. Provide technical reports, factsheets and environmental and planning tools for government and policy makers