 |
|
|
|
|
RIRDC Completed Projects in 2005-2006 & Research in Progress as at June 2006
To Organic Systems Research in Progress
Organic Systems - Completed Projects PROJECT No PROJECT TITLE RESEARCHER PHONE ORGANISATION 1.1 Organic production systems: system design and environmental sustainability
DAQ-284A World class production systems for new Australian apple varieties Dr Simon Middleton (07) 4681 1255 Department of Primary Industries and Fisheries (Qld) 2 Conversion processes
DAW-112A Organic conversion demonstration at Kununurra Mr. Steven McCoy (08) 9368 3960 Department of Agriculture (WA) 5 Communication and facilitation
MCK-3A Understanding the export potential for organics – opportunities and barriers Dr David McKinna (03) 9696 1966 David McKinna et al Pty Ltd 1.2 Organic production systems: Pests and diseases
DAQ-327A Integrating pyrethrum against fruitspotting bugs into organic tropical fruit production Dr Harry Fay (07) 4048 4663 Department of Primary Industries and Fisheries (Qld)
1.4 Organic production systems: soils
DAN-246A Fertiliser for sustainable increase in available soil phosphorous for organic farming systems (extension to DAN-195A) Dr Jeffrey Evans (02) 6938 1889 NSW Department of Primary Industries UWA-81A Adding value to organic pasture - microbes and minerals A/Prof Lynnette Abbott (08) 6488 2499 University of Western Australia
ORGANIC SYSTEMS - COMPLETED PROJECTS
1.1 Organic production systems: system design and environmental sustainability
Project Title World class production systems for new Australian apple varieties RIRDC Project No.: DAQ – 284A Researcher: Dr Simon Middleton Organisation: Department of Primary Industries & Fisheries, Queensland (DPI&F)
PO Box 501
Stanthorpe Q 4380Phone: 07 4681 6100 Fax: 07 4681 1769 Email: simon.middleton@dpi.qld.gov.au Objectives
·1 To develop organic production systems and tree management packages for ‘RS103-130’ and other new scab-resistant Australian apple selections, and to demonstrate that ‘RS103-130’ can be successfully grown organically under the high disease, pest, weed and environmental pressures of southern Queensland. Background
Apple scab is a major disease that has restricted the ability of Australian apple growers to adopt organic production systems. The DPI&F apple breeding program has developed several scab-resistant apple selections that have the potential to be grown organically. Research
A one hectare block of organically grown scab-resistant apple trees was established on the property of a major apple grower in the Stanthorpe district of Queensland. Six high density planting system trials for a range of rootstocks and tree densities were planted at Applethorpe Research Station to develop tree management packages for the scab-resistant apple selections, and to provide fruit for consumer evaluation. Outcomes
Semi-commercial quantities of Australia’s first crop of organically grown, Australian-bred scab-resistant apples were harvested in March 2006, and sold through an organic wholesaler. Field trials have identified appropriate strategies for organic production of scab-resistant apples, and these are included in an organic apple manual. Implications
The project has shown that the new apple ‘RS103-130’, can be grown organically without infection of leaves or fruit with apple scab, whereas ‘Galaxy’ in the same organic orchard had up to 5% scab infection of fruit. ‘RS103-130’ will be a viable addition to the varietal mix for organic apple producers, and give consumers a high quality eating experience whilst also providing a healthy snack product. Publications McWaters, A.D., Horlock, C.M., Nimmo, P.R., Zeppa, A.G. & Middleton, S.G. (2006). Organic Apple Production in Australia - A Practical Guide. Department of Primary Industries & Fisheries, Queensland. (in preparation). McWaters, A., Zeppa, A. & Middleton, S. (2006). Producing apples free of black spot. Australian Organic Journal 66: 46-47.
McWaters, A., Zeppa, A. & Middleton, S. (2006). Organic production of black spot-resistant apples. Australian Organic Journal 65: 46-47.
McWaters, A., Zeppa, A. & Middleton, S. (2005). Organic production of new black spot resistant apples. Tree Fruit. November 2005. pp. 4-6.
McWaters, A., Zeppa, A., Middleton, S., Rickard, D., Nimmo, P., Cameron, D. et al. (2004). Developing systems for low input and organic apple production based on new black spot resistant selections. Apple & Pear Australia Ltd 2nd National Conference, Adelaide.
Middleton, S., Nimmo, P. & Zeppa, A. (2003). Systems for organic production. Tree Fruit. September 2003. pp. 20-21.
Project Title: Organic Conversion Demonstration at Kununurra RIRDC Project No.: DAW-112A Researcher: Steven McCoy Organisation: Department of Agriculture Western Australia Phone: 08 9368 3960 Fax: 08 9368 3355 Email: smccoy@agric.wa.gov.au Objectives · To establish on farm demonstration sites displaying organic conversion for mangoes to assist Kununurra growers develop organic production systems for mangoes and other crops. Background A strategic assessment of the potential for organic horticulture in WA identified mangoes, citrus and cucurbits as prospective crops for conversion to organic production in the Ord River Irrigation Area at Kununurra in the far north east of Western Australia. A major impediment to conversion is the limited knowledge and experience in commercial organic production systems in the region. Research An organic conversion demonstration site was established on an existing commercial mango orchard and provided a practical and realistic example for other growers in the region to scrutinise and consider. The technical feasibility and commercial viability of certified organic mango production was investigated and reported. Outcomes The transition to organic production was assisted by a prior shift in management from chemical intensive approach towards a more biological approach with reduced synthetic chemical inputs. A relatively small area of the operation was converted to organic initially in order to gain knowledge, experience and confidence without significant commercial risk. Choosing a relatively isolated site reduced the risk of contamination from adjacent land use and minimised the area needed for buffer zones between the two systems. Older trees were considered more suitable than younger trees because of more extensive root system, less weed pressure, ability to cope with mild pest or disease pressure and possibly reduce biennial bearing tendency. Results overall indicated no major deterioration in soil conditions or tree health. Management of nitrogen release from compost and mulch together with irrigation frequency is considered important to avoid fruit quality problems.
Yield results for 2004 were similar to conventional production. For organic mangoes, production costs were slightly higher and gross margin returns were higher due to an average price premium of $2.00 per tray for the organic mangoes. However the current WA market for organic mangoes is relatively small, although expanding rapidly. Market development effort is required to lift demand volumes. Close management of supply volumes is important to maintain orderly market development
Implications The demonstration site is now seen as a model example of organic mango production. Interested growers can view the site and speak with the owners of the property regarding organic management techniques and conversion issues. The region has a number of growers who are developing a biological approach to their farm management and three growers have progressed to formal organic certification. One grower has entered organic certification for grapefruit and cucurbit (pumpkin) production. A common pack-house is being used for washing, grading and packing the organic fruit and this offers the prospect for collaboration among these organic producers in developing new (export) markets as well as ensuring orderly supply on domestic markets. Publications Organic mangoes: a production guide. Department of Agriculture Western Australia, Bulletin.
5. Communication and facilitation
Project Title: Understanding the export potential for organics – opportunities and barriers RIRDC Project No.: MCK-3A Researcher: Dr David McKinna Organisation: David McKinna et al Pty Ltd
Rear 131 Victoria Avenue
ALBERT PARK VIC 3206Phone: 03 9696 1966 Fax: 03 9696 1965 Email: david.mckinna@davidmckinna.com.au Objectives The central aim of this project is to identify opportunities for organic exports and to investigate impediments to the Australian organic industry in accessing export markets. Background In recognition of the continued growth and market potential of the organic industry, RIRDC has administered a dedicated organic research and development program since 1996, in order to foster the industry’s development. As a component of that broader body of research work, this report focuses on identifying global market opportunities for Australian organic products. Research This report has been based largely on desk research and analysis. The limitation with the desk research has been the poor availability of literature and the questionable validity of data in this emerging export industry. Therefore, the analysis is also reliant on the experience of the lead consultant on the study, Dr David McKinna. David McKinna et al Pty Ltd draws on over 20 years experience in researching Australia’s food and wine export markets. Markets covered are the US, the UK, Continental Europe, Japan, Singapore, Hong Kong, China, Taiwan, Malaysia and New Zealand. Outcomes The report concludes that for nearly all organic products, in virtually all the developed economies, demand outstrips supply. The report concludes that the higher prospect markets for Australian organic exports are Japan, Continental Europe, the United Kingdom (UK), the US and South East Asia. In the longer term, China, Taiwan and South Korea will also emerge as growth markets. In terms of product categories, the best prospects for Australia are likely to be in beef and lamb, cereal based products, processed foods, juices, beverages, wine, jam, honey and condiments. Prospects for perishable products, such as fruit, vegetables and dairy products, are judged to be confined to closer markets, such as South East Asia. Implications Demand for organics is more likely to be stronger for products within the following parameters: ·5 Those which have heavy use of chemicals in their conventional production systems The market potential for Australian organic products is likely to be greater in markets where:·6 Products eaten with a minimum of preparation
·7 Products which have a distinct taste profile and are eaten for enjoyment
·8 Products for infants and growing children
·9 Products eaten primarily for their nutritional attributes.
·10 Australia is a globally competitive producer of the standard product category. ·11 Australia has a greater reputation regarding capability and integrity in the supply chain.
·12 Australia has seasonal products in a unique window of opportunity.
·13 Australia has unique or differentiated products.
·14 Australia has geographic proximity to the market (particularly in the case of perishable products.
Publications David McKinna et al Pty Ltd (2006). Export Potential for Organics – opportunities and barriers. RIRDC Publication No. 06/061, Union Offset Printing, Canberra, ACT.
Organic Systems - Research in progress PROJECT No PROJECT TITLE RESEARCHER PHONE ORGANISATION 1.1 Organic production systems: system design and environmental sustainability
DAQ-336A Growing organic prawns in inland saline systems Mr Steve Slattery 07 34068623 Queensland Department of Primary Industries and Fisheries DAV-222A Establishing perennial pastures – the foundation for sustainable organic farming systems Ms Vivianne Burnett (02) 6030 4500 Department of Primary Industries (Vic) UNE-95A Matching cultivars and inputs in organic vegetable production Dr Paul Kristiansen (02) 6773 2962 University of New England 1.1 Organic production systems: system design and environmental sustainability
Project Title Growing organic prawns in inland saline systems RIRDC Project No.: DAQ-336A Start Date: 1/11/2005 Finish Date: 31/10/2006 Researcher: Steve Slattery Organisation: Queensland Department of Primary Industries and Fisheries Phone: 07 34068623 Fax: 07 34068698 Email: Steve.Slattery@dpi.qld.gov.au Objectives (i) Objectives/aims of the proposed research ·1 Investigate the organic standards that relate to low and high density grow out ·2 Negotiate contract with industry partner for access to grow out sites and for production procedures
·3 Use banana prawn seed (post larvae) for stocking ponds and source juveniles from these ponds for tank trial
·4 Prepare ponds using organic procedures for introduction of seed
·5 Stock ponds at low density rates
·6 Manage water quality and monitor prawn growth rates during the growing season
·7 Concurrently conduct organic feed trials with juveniles as a contingency for poor growth rates in low density ponds
·8 If growth rate in low density ponds is too slow, apply limited supplemental feeding of the most effective organic feed identified from tank trial
·9 Conduct treatment and packaging trials using a range of organic methods to identify optimum treatment
·10 Drain harvest the ponds retaining water in separate reservoir for future use
Current Progress The organic standards for aquaculture from both domestic and overseas certifying bodies have been investigated. Both BFA and NAASA have aquaculture standards. If an Australian prawn farmer wishes to export then they may have to comply with either FDA or EU standards as well. The only organic standard that has been written specifically for prawns comes from the Natureland Company which actually has the most detailed requirements for producers. The industry partner provided three ponds which were prepared using organic procedures for the grow-out experiment. These were stocked predominately with banana prawns but after apparent poor survival rates black tiger prawns were also stocked into two of these ponds.
Pond water qualities and growth rates were monitored. An unexpected need to rely more heavily on a lower protein organic feed caused growth rates to slow by January. Supplemental feeding with non-certified commercial prawn feed was initiated. Due to the lack of supply by the certified-organic feed producing industry partner, and the limited growth achieved with alternative certified organic feeds in the associated feed trial at BIARC, farm staff decided to continue with the use of the uncertified prawn feed.
Juveniles removed from the ponds before this uncertified supplemental feeding were fed a range of organic wheat-based diets in replicated experiments at BIARC. While none of these certifiable diets resulted in growth rates as high as the uncertified commercial diet, survival rates were similar for most treatments. The information produced by the feed trial as well as another planned early next year will allow further development of an organic prawn feed that can be produced domestically.
Modified atmosphere packaging (MAP) trials were conducted at the farm on raw banana prawns, raw black tiger prawns and cooked black tiger prawns. Subsequent chilled storage spanned an 18-20 day period with good food quality maintained up until the last two days of storage. No blackspot developed at any time. These successful storage times are sufficient to make the export of retail-sized packs of organically produced prawns feasible in the chilled state. Chilled product would provide a premium over frozen product in the discerning markets that would most likely be targeted with organic product.
Pond production figures are still being compiled but for banana prawns are generally very low due to severe mortality events at the farm during excessively hot conditions in January. Only about 5 kg were reported to have been recently harvested from the most severely affected pond (B1), from which 1.25 kg had been harvested earlier for the MAP trial. The other two ponds (B2 and B3) containing mainly black tiger prawns had much better production, although again they had been grown for the final several months using non-certified feeds. A total of 100.94 kg was harvested from B2 – by comparison, 139.31 kg was harvested from the conventional pond beside it. Additionally, 3.5 kg of raw prawns and 4.2 kg of cooked prawns had been harvested earlier for the MAP trial. A total of 44.56 kg was harvested from B3. This lower production was reportedly due to mortalities related to the power failure of an aerator. However, these production figures provide little information regarding the true potential for certified organic prawn production. Further work regarding locally available and improved diets and better farm operating conditions will be necessary.
Project TitleEstablishing perennial pastures - the foundation for sustainable organic farming systems RIRDC Project No.: DAV-222A Start Date: 01-Jul-04 Finish Date: 30-Jul-07 Researcher: Ms Vivianne Burnett Organisation: Department of Primary Industries (Vic)
RMB 1145
Chiltern Valley Road
RUTHERGLEN VIC 3685Phone: (02) 6030 4500 Fax: (02) 6030 4600 Email: viv.burnett@nre.vic.gov.au Objectives · To determine sustainable methods of perennial pasture establishment for organic and in-conversion farming systems. Current Progress The project comprises three activities. Firstly, a survey of organic producers has been conducted to determine current methods of perennial pasture establishment. The survey conducted phone interviews with 160 certified organic primary producers in Victoria, New South Wales and South Australia and achieved a response rate of 85%. Preliminary data analysis has indicated that the majority of producers are actively establishing perennial pastures in their farming systems. Most success has been achieved with cultivated seed-beds and the greatest barriers to successful establishment and persistence have been identified as available moisture and weed management. Secondly, an experimental program to test perennial pasture establishment methods in organic dryland farming systems has been established with two sites (cultivated and direct drilled) sown in 2005. Germination and persistence of perennial species on the cultivated site has been excellent with plant densities equivalent to conventional systems achieved one year after sowing. The direct drilled site was not successful with all sown species not establishing due to red legged earthmite infestation. Thirdly, a producer study tour (Rutherglen and Tarrawingee) and workshop was conducted in March 2006 with over 65 producers attending. Evaluation from the tour has demonstrated that producers think that available moisture and the management of weeds are critical for success in pasture establishment. There was also a commonly held view that grazing management could be used to bring back perennial species, including native species, into farming systems. The majority of producers had observed native grass species on their farms and were actively promoting these species.
Project Title Matching cultivars and inputs in organic vegetable production RIRDC Project No.: UNE-95A Start Date: 01-Jul-2005 Finish Date: 30-Nov-2007 Researcher: Dr Paul Kristiansen Organisation: University of New England Phone: (02) 6773 2962 Fax: (02) 6773 3238 Email: paul.kristiansen@une.edu.au Objectives · The project will investigate relationships between crop cultivars, phosphorus (P) and soil in organic vegetable production by characterising the soil environment in organic vegetable farms, investigating P-accumulating cover crops quantifying the nutrient dynamics of organic-permitted sources of P and relating P uptake to the plant's root system. Current Progress Field survey
Soil sampled from organic and conventional vegetable farms at three sites in NSW and Queensland in February 2005 and 2006. Preliminary analyses indicate that soil nutrients levels were similar amongst farms and phosphorus was adequate on organic farms. Soil microbial activity was compared using cotton strips and respiration to develop a simple and efficient method for measuring biological activity. A journal paper reporting this work is almost finished and part of the literature review was presented at IFOAM2005.Glasshouse trials
Phosphorus response curves have been developed for corn (cash crop), field peas and faba beans (cover crops) to determine suitable rates for applying fertiliser inputs in subsequent trials. Soil solution analysis was carried out at different stages of corn growth to identify the cultivar differences in solubilising and taking up organic phosphorus (and nitrogen) sources. Pot trials to determine (a) the partitioning of phosphorus in cover crops and (b) the effect of different fertilisers on cover crop phosphorus accumulation in contrasting soil types are in progress.
1.2 Organic production systems: Pests and diseases
Project Title Integrating pyrethrum against fruitspotting bugs into organic tropical fruit production RIRDC Project No.: DAQ-327A Start Date: 01-Aug-04 Finish Date: 15-Oct-07 Researcher: Dr Harry Fay Organisation: Department of Primary Industries and Fisheries (Qld)
PO Box 1054
MAREEBA QLD 4880Phone: (07) 4048 4663 Fax: (07) 4092 3593 Email: harry.fay@dpi.qld.gov.au Objectives · To develop strategies for the effective integration of pyrethrum against fruitspotting bugs (Amblypelta spp.) into pest management systems for the organic production of tropical and subtropical tree fruit and nut crops, based on acceptable standards for organic production. Current Progress An extensive series of laboratory bioassays with pyrethrum and various botanical oils indicated that oil synergists should be applied 24 hours before the pyrethrum for it to be efficacious against Amblypelta. A rate of 1000 ppm pyrethrum and 5 ml of oil/L of water appeared to optimise efficacy. Tea tree oil was confirmed as the best synergist, potentially providing an additional opportunity for this product. Field trials were set up in avocado (pyrethrum and sesame or tea tree oil), cashew (pyrethrum and canola oil) and carambola (pyrethrum and tea tree oil) crops from September 2005. Individual trees were sprayed (fortnightly) based on bug presence or feeding damage above a threshold of 20% of fruit surveyed. In the avocados and cashews, none of the pyrethrum treatments provided significant control of bug activity. The damage threshold may have been set too high, or the spray coverage of the trees inadequate. A separate assessment confirmed that bugs should be killed by both air-borne droplets and leaf deposits of pyrethrum and oil. The carambola trial was inconclusive because of relatively low bug damage. Pyrethrum did not reduce the numbers of beneficial insects in any trial. Some prospective farm trial sites were lost during Cyclone Larry.
1.4 Organic production systems: soils
Project Title Fertiliser for sustainable increase in available soil phosphorous for organic farming systems (extension to DAN-195A) RIRDC Project No.: DAN-246A Start Date: 01-Jul-2005 Finish Date: 30-Nov-2007 Researcher: Dr Jeffrey Evans Organisation: NSW Department of Primary Industries Phone: (02) 6938 1889 Fax: (02) 6938 1822 Email: jeffrey.evans@agric.nsw.gov.au Objectives · To develop a fertiliser strategy for sustainable increase in plant available soil phosphate, for application in organic broad-acre farming. · It is proposed to carry out experiments to supplement those of a previous project (DAN195A) to lead to (i) the development of commercially viable reactive phosphate rock - sulphur fertiliser (RPR/S) blends effective in increasing plant available soil phosphate, and (ii) a better understanding of the conditions for effective use of RPR/S. A further objective is, (iii) to assess soil phosphate response to commercial chemical and microbial additives purporting to increase available phosphate.
Current Progress Reactive phosphate rock (RPR) enriched with elemental sulphur (S) is being investigated for its ability to improve available phosphorus in soils and to sustain any improvement. The purpose of the S is that its microbial oxidation in soil releases acidity, which is required for release of plant available P from RPR. Ground RPR+S incorporated with soil in 2002 continued to give significant increase in available P in 2006. Whilst the initial application rates would be considered high (500 kg/ha for both the phosphate rock and sulphur), nevertheless this study showed that the strategy was worth pursuing, particularly as the longevity of the available P response to RPR+S would dilute the up-front capital cost. Conditions for effective use of RPR+S are being investigated, including determining minimal effective rates. As the earlier studies used only a single high rate of RPR and S, four field trials were established to investigate the available P response to a range of rates of RPR (0, 100, 200, 300, 400, 500 kg/ha) crossed with rates of S (0, 50, 100, 200, 400 kg/ha): one in 2004 and three in 2005. The sites were mildly to strongly acidic, and mostly loams except for one acidic site with a light-textured sandy surface soil.
At the site established in 2004 [only one RPR level (500 kg/ha) was used with a range of S rates], maximal available P was achieved with RPR+S (500+300 kg/ha), though agronomically useful increases in available P were also achieved at lower rates of S. The strong natural acidity at this site has also resulted in useful increase in available P from the RPR treatment without S, at the third season since application of the fertiliser.
At the light-textured, acidic site established in 2005, useful increase in available P has been achieved with rates of RPR+S of 200+100 kg/ha, and larger increases at higher rates of the fertiliser. At the loamy, acidic site, significant increases in available P have also been achieved, though at relatively higher rates of RPR+S than in the light textured soil, because P buffering capacity was higher. At the loamy mildly acidic site, available P increases have been significant though smaller than at the more acidic sites. All increases in available P have thus far been sustained for two seasons.
These experiments are showing that, the effectiveness of RPR+S, in terms of the level and rate of improvement in available P, is influenced by the relative levels of RPR and S, the initial soil pH (despite the addition of S) and the soil texture. In addition the amounts of RPR+S to achieve optimal available P, depended on the initial soil level of available P. For example, superimposing rates of RPR+S(30%) on the acidic loamy soil, amended so as to change the initial level of available P (IP), showed that the available P response (Y) to RPR+S (PS) was defined simply as Y = IP + 0.009 x PS. However, the regression coefficient for the rate of change in Y in response to RPR+S was strongly dependent on initial soil pH, decreasing linearly with increase in initial soil pH, ie. [Y = IP + [(0.0302 – 0.0050 x pH) x PS]. In other words the higher the initial soil pH, the more difficult it was to change the level of available P using RPR+S.
The effect of RPR+S on available P in this soil was also compared with the response to soluble P fertiliser: a shift of 5ppm in available P required an input of soluble P equivalent to applying superphosphate at 250 kg/ha. The comparison showed that at the initial pH of this soil (4.4) the amount of RPR+S(30%) required to produce a similar change in available P as with superphosphate was 2.5x the latter. Therefore, it will be more expensive to improve or maintain soil P fertility with RPR+S than with superphosphate, unless the efficiency of the reaction of RPR with S can be increased.
The above field trials indicate that RPR+S is a strategy for sustainable improvement in P fertility on organic farms, more effective than RPR alone, however despite the addition of S, the strategy will be still be more effective when applied to acidic soil, ie. before a soil liming program. The cost (amount of P fertiliser) of recovering P fertility will depend on the initial level of impoverishment of soil P.
The project is now working with a small commercial manufacturer of fertiliser (Soil Solutions, Cowra) and this company has shown that a ground RPR product with a maximum of 30%S (P-Lift) can be manufactured safely. Agronomic evaluation of this product is required.
The field trial with 14 commercial products claimed to increase available P or plant uptake of P was established in winter of 2006. Drought has severely compromised evaluating these products and their assessment will be carried over to 2007.
Back to the top
Project Title Adding value to organic pasture - microbes and minerals RIRDC Project No.: UWA-81A Start Date: 01-Jan-2004 Finish Date: 31-Dec-2006 Researcher: Prof Lynette Abbott Organisation: University of Western Australia Phone: (08) 6488 2499 Fax: (08) 6488 1050 Email: labbott@cyllene.uwa.edu.au Objectives · To monitor and interpret changes in soil biological, physical and chemical characteristics in response to the use of soil amendments for organic pasture production and in adjacent conventional pasture systems. Current Progress 1. A three year field experiment compared conventional pasture production (soluble fertilisers) with organic pasture production during the ‘conversion’ phase (rock phosphate and silicate minerals). After two years, soil biological properties (microbial biomass C, cellulase activity and phosphatase activity) were not affected. Soil and plant material from regular samplings are being analysed for soil pH, Colwell P and K, pasture yield and plant nutrients. 2. A field experiment was conducted in spring 2006 to determine whether mica increased P availability from rock phosphate (plant P content, soil available P) and whether either mineral affected soil microorganisms (microbial respiration, microbial biomass C). Initial results show that neither addition affected microbial respiration.
3. In a glasshouse experiment finely ground rock phosphate, mica and basalt were added to pasture soil. The results showed that these minerals altered the structure of the soil microbial community and affected soil biological activity (microbial respiration, dehydrogenase activity) in ways that were not detectable in the field experiments.
4. The glasshouse experiment design was used again to determine whether microorganisms colonising the surfaces of the mineral fertilisers were different from those in bulk soil. Initial results indicate the microbial community structure on mineral grains is different from community structure in bulk soil.
Site map Contact us Feedback Links Disclaimer Privacy Statement
Last updated: Janaury 2007 Copyright © RIRDC 2006
http://www.rirdc.gov.au/comp06/org1.html
