Biological amendments for the Australian grains industry: summary review and framework

[摘要] There is growing interest in the use of biological soil amendments to help support soil condition and plant productivity in Australian cropping systems. Many biological amendments can change nutrient availability, soil physical, chemical and/or biological condition, and plant growth. However, yield benefits from their use are uncertain and difficult to predict, and current guidance on how to navigate the growing product range is lacking.Research into biological amendments continues to have a dominant focus on high value horticultural crops compared to broad acre cropping. Few broad-acre studies demonstrate a systematic approach to targeting the use of amendments to a well-defined production constraint. In broad acre agriculture there is a strong systematic and peer-review RD approach in place for rhizobia, but it is less well developed for the wider amendments industry. There are however changes within the wider industry, with growing emphasis on research-based products, biologically based practices, and industry standards/regulation. It is important that growers interested in trialling biological amendments can be guided by a systematic approach to product selection and on-farm trialling.Although useful to broadly categorise biological amendments into inocula, biostimulants, and organic amendments, variation within each of these groups is large. There is an inability to compare the composition of the wide range of amendments, and to clearly identify how different amendment types work. This limits the development of a targeted systematic approach to selection and testing. Biological amendments have important differences in the way in which they influence plant growth - their so-called “mode of action”. The mode of action can have a direct effect on the plant, or it may work indirectly through improving soil condition. For many amendment types the mode of action can be unclear, or amendments may have more than one mode of action. Identifying the main constraints to plant growth provides a focus for selection of an amendment. It will also help guide what to monitor and how to evaluate its effect. This report summarises the potential role of biological amendments in Australian broad-acre agriculture through these mode of action pathways. It draws the literature evidence in a framework to highlight which types of amendments have the potential to change plant growth through plant physiological responses and/or changes to soil condition. In conclusion the report highlights research gaps and proposes a pathways forward to support broader field based evaluation of biological amendments in Australian broad acre systems. Comparison of guidance on fertiliser use (the 4Rs of nutrition: right source; right rate; right time; right place), highlights some of the research gaps in the use of biological amendments. In particular, how the timing, placement, and frequency of application of biological amendments might influence plant growth responses. Additionally, a wider systems approach is often lacking from research trials, and an understanding of the compatibility of biological amendments with conventional inputs (fertilisers, pesticides/herbicides) is lacking. The short-term nature of research trials has limited the opportunity to assess cumulative benefits, optimise the use of products, and understand the impact over a range of seasonal conditions. To address these gap there is a need for greater collaborative field-scale research between the amendments industry, researchers, and farmers. The development of tools to allow comparison of amendments, and support informed decision making would be valuable in supporting greater local on-farm testing.

[发布日期] 2018-07-17 [发布机构] CSIRO

[效力级别] Crop and Pasture Production not elsewhere classified [学科分类] 地球科学(综合)