NRM North. Compost and compost tea trial at Patterdale final report

Transcription

1 NRM North Compost and compost tea trial at Patterdale final report June 2013

2 Macquarie Franklin was formed in April 2011 by the merger of two Tasmanian based consulting firms - Agricultural Resource Management (ARM) and Davey & Maynard. Macquarie Franklin Head Office 112 Wright Street East Devonport Tasmania 7310 Phone: Fax: info@macfrank.com.au Web: Report author: Leanne Sherriff An appropriate citation for this report is: Macquarie Franklin, June 2013, Compost and compost tea trial at Patterdale final report, Prospect TAS Document status: FINAL Date Status /Issue number Reviewed by Authorised by Transmission method 19/6/13 DRAFT 1 L Peterson L Sherriff 27/6/13 DRAFT 2 C Westmore & D White L Sherriff This report has been prepared in accordance with the scope of services described in the contract or agreement between Macquarie Franklin and the Client. Any findings, conclusions or recommendations only apply to the aforementioned circumstances and no greater reliance should be assumed or drawn by the Client. Furthermore, the report has been prepared solely for use by the Client and Macquarie Franklin accepts no responsibility for its use by other parties. i

3 Contents 1 Background Methodology Trial design Treatment details Compost tea Trial assessment Year Year Results Trial assessments Results from physical assessment of trial Results from biological assessment of trial Results from chemical assessment of trial Compost tea analysis (2012 and 2013) Discussion Trial results Compost tea analysis (2011 and 2012) Recommendations Appendices Appendix A: Trial map Appendix B: Macquarie Oil compost analysis Appendix C: Analysis of compost tea and compost from which it was brewed (November 2011) Appendix D: Analysis of compost tea and compost from which it was brewed and Macquarie Oil compost (June 2012) Table index Table 1 Summary of number and size of plots in trial... 4 Table 2 Description of parameters assessed... 7 Table 3: Summary of microbiological testing of composts and compost tea ii

4 Figure index Figure 1: trial plots marked out and poppies sown September Figure 2: Average number of poppies per m 2, in compost and control treatment plots (from 11/11/11)... 8 Figure 3: Average height poppies in compost and control treatment plots (from 11/11/11)... 8 Figure 4: Ground cover by treatment and year... 9 Figure 5: Plant height by treatment and year... 9 Figure 6: Poppy height by treatment (measured 12/12/11) Figure 7: Number of poppies at different growth stages by treatment (measured 12/12/11) Figure 8: Root depth by treatment (no results for 2012) Figure 9: Count of earthworms by treatment and year Figure 10: Rating of fungal hyphae in soil by treatment and year Figure 11: Soil organoleptic assessment by treatment and year Figure 12: Soil structure rating by treatment and year Figure 13: Glomalin by treatment (2012 only) Figure 14: Total microbiology by treatment and year Figure 15: Total bacteria by treatment and year Figure 16: Total fungi by treatment and year Figure 17: Microbial diversity by treatment and year Figure 18: Mycorrhizal colonisation of pea roots by treatment (data not available for 2012) Figure 19: Phosphorous by treatment Figure 20: Potassium by treatment Figure 21: Calcium by treatment Figure 22: Zinc by treatment Figure 23: Boron by treatment Figure 24: Sulphur by treatment Figure 25: Sodium by treatment Figure 26: Exchangeable sodium percentage by treatment Figure 27: ph by treatment Figure 28: Total carbon by treatment Figure 29: carbon to nitrogen ratio by treatment Figure 30: CEC by treatment iii

5 Executive summary The aim of the trial is to determine the effects of compost and compost tea applications on soil health, structure and biology, and the response of key plant growth measures to the treatments. The overall objective is to understand the effect of these treatments in improving declining soil structure and soil health. The trial was designed to include 3 replicates of each treatment (control, compost and compost tea), and was run over two growing seasons in a poppy and then pea crop, with an annual grass cover crop in between. Variables assessed in the trial included: Glomalin Microbial diversity Microbial biomass AMF ( mycorrhizal associations) Complete nutrient analysis (including ph, EC, total carbon) Soil structure, smell Number of earthworms Plant growth (height, root development, plant growth stage). There were some effects of the compost treatment observed on soil biology during the course of the trial, however the significance of the results was reduced by the high standard error of the compost treatment. This may indicate that either the application of the compost is not as even as desirable across the plot/paddock, that there are issues with sampling technique, or analysis of soil biology or a combination of the three. The results from the nutrient testing indicated that a number of nutrients were higher in the compost treated soil than the control (potassium, zinc and sodium). The levels of nutrient applied in the compost does not account for these increases, they appear to be a result of transformations in the soil. Whilst the changes are statistically significant compared to each other, none of these increases or decreases significantly altered any elemental values outside of acceptable ranges and would have minimal impact on plant growth. The compost treatment significantly promoted mycorrhizal colonisation compared to both the control and compost tea treatments and the compost tea treatment had a higher mycorrhizal colonisation compared to the control. The control plots used in this trial design measured the background variation in the variables measured due to environmental factors. This highlighted a very large difference in the biomass of microorganisms between year 1 and year 2 of the trial. Consultation with the specialist soil biology laboratory confirmed that this variation would be extremely unlikely to be caused by analytical error. Factors which may have caused this observation (order of greatest effect to least effect) are: 1. Sampling micro-location. Samples must be taken in the rhizosphere. There can be approximately 10 to 100 times more microorganisms in rhizosphere soil than nonrhizosphere soil. 2. Herbicide/other agrochemical application. 1

6 3. Plant growth stage at sampling. Actively growing plants produce more exudates that stimulate soil microbiology. 4. Environmental conditions, such as temperature, moisture, nutrients, etc. leading up to the sampling time can make a large difference. It is also important to note that the composts used in the trial did vary in terms of their microbial composition and that the compost teas did not reflect the biological composition of the composts from which they were produced. Compost tea brewing is not straightforward and the tea should be checked for biology before being used. Key recommendations based on the results of the trial are: It is important to assess the microbial components of compost tea and not assume that it will reflect the constituents of the compost from which it is made. The compost tea brewing technique should be modified where necessary so that the appropriate balance of fungi to bacteria is achieved and that overall numbers of microorganisms are high and they are diverse enough. It would appear from the results of this trial that getting the compost tea brew right is not straightforward. It is also important to understand the actual composition of the microbiology in compost which is added it can be expensive to use, so being confident of the quality is critical. Results obtained from measuring glomalin do not justify the cost of the test. No clear effect of compost or compost tea was observed on microbial biomass or microbial diversity. However compost did appear to promote mycorrhizal colonisation. Compost treatment was found to result in elevated levels of some nutrients (potassium and zinc) and depressed levels of others (sulphur), and it did not significantly affect soil carbon. The results cast some doubt on the value of one off measurements of biological parameters. However, it is acknowledged that as the understanding of these parameters improves, the value of this testing will also improve. In the meantime replicated plots and multiple tests, which include control plots, are essential in order to be able to determine any meaningful trends or effects of treatments. However, the costs of the analysis may be prohibitive in including measures of biological parameters in replicated trials. Given the costs/effort of applying these treatments in a broad acre situation it is likely that it is more cost effective to encourage soil biology through management practices such as green manure crops, incorporation of stubbles, minimising use of chemical applications, etc and to manage soil nutrients through application of appropriate fertilisers. While compost tea is a cheaper alternative than compost (and therefore might be more readily used in a broad acre situation), it is a lot more difficult to get right. 2

7 1 Background The compost and compost tea trial project is a joint project between Macquarie Franklin and R&C Westmore, funded by NRM North (under Partnership Agreement 2061). The project is hosted at Patterdale (Nile) in Willow paddock which is an irrigated centre pivot circle on clay loam soil. The project began in September 2011 and was funded for 2 years (until 30 June 2013). The project involved application of compost and compost tea treatments in replicated plots, with control plots also included. The aim of the trial was to determine the effects of compost and compost tea applications on soil health, structure and biology, and the response of key plant growth measures to the treatments. The overall objective was to understand the effect of these treatments in improving declining soil structure and health. Figure 1: trial plots marked out and poppies sown September

8 2 Methodology 2.1 Trial design The trial was designed to include 3 replicates of each treatment. The Control treatment was the basal fertiliser regime for the entire crop, the two other treatments were Compost Tea and Compost applied in addition to the basal fertiliser regime. Once established the trial was georeferenced using dgps and mapped. Refer to Appendix A for the trial map. Table 1 Summary of number and size of plots in trial Treatment Number of plots Area of plots (ha) Compost 3 0.9, 0.6, 0.3 Compost tea 3 1, 0.7, 0.4 Control 3 0.8, 0.8, 0.9 Total trial area NA 6.4ha 2.2 Treatment details Compost was purchased from Macquarie Oil Pty Ltd. A copy of the typical compost analysis is provided in Appendix B. In year 1, compost was applied on 2 September 2011 at a rate of 6m 3 /ha. The paddock was multidisced prior to compost application (1/9/2011), and then poppies were sown on 3 September The standard fertiliser regime for poppies was used for all plots (base fertiliser 300kg/ha 3,15,13, with 30kg Boron per tonne), plus additional nitrogen in the form of 2 applications of urea 75 kg/ha. Compost tea applications were made on 11 November 2011 and 29 November 2011 at a rate of 100L/ha (details on compost tea production are presented in section 2.2.1). A sample of tea and the compost from which it was made were both sent for assessment of microbiology by the CIAAF laboratory (11/11/11). Results are presented in Appendix C, and discussed in 3.2. The poppies were harvested on 26 January 2012, and a cover crop of Tama rye grass sown on 2 March In year 2 of the trial, compost was applied June 2012 at a rate of 6m 3 /ha. The Tama grass cover crop was cultivated using a mould board plough in mid October The paddock was then multidisced, and then multidisced again prior to sowing peas on 27 November The standard fertiliser regime for peas was used for all plots (pre-sowing fertiliser 300kg/ha 0,6,17, and then at drilling 125kg/ha 6,5,13 plus molybdenum). Compost (6m 3 /ha) was applied on 17 December 2012 (the crop had emerged). Compost tea was applied on 6 June 2012 and 8 January 2013 at a rate of 100L/ha (details on compost tea production are presented in section 2.2.1). In June 2012 samples of the compost supplied by Macquarie Oil, the compost produced at Patterdale and the compost tea brewed from the Patterdale compost were all sent for assessment of microbiology by the CIAAF laboratory (6/6/12). Results are presented in Appendix D, and discussed in

9 2.2.1 Compost tea Compost tea was made from compost produced on-farm (composted for 6-9 months). Ingredients for compost were: Triticale straw Eucalypt woodchips Sheep manure Cow manure Lucerne hay Compost tea brew consisted of the following: 2L fish emulsion 3L kelp 0.5L humate 100ml molasses 1kg flour 5kg compost 950L water This was brewed for 24 hours in purposed-designed compost tea brewer, with air circulating through to aerate and mix the brew. Prior to application an additional 2.5L fish emulsion, 1.5L kelp and 0.5L humates was added and the tea was diluted in 950L water. Tea was applied at a rate of 100L/ha. 2.3 Trial assessment Year 1 On 11 November 2011, an assessment of poppy establishment and poppy height was made. This was done using 1 m 2 quadrats which were randomly located 5 times within each plot (ie giving 5 replicates per plot and 5 x 3 replicates per treatment). This was only done for control and compost treatments as compost tea had not yet been applied. The total number of poppies within each quadrat was counted and average height of poppies within the quadrat was measured. On 12 December 2011 soil sampling was done and further physical assessments of the trial were made (for all treatments) (refer to Table 2 for comprehensive details on assessments). 5

10 Soil sampling 15 cores from 0-10 cm depth were taken from each plot, mixed and sub-sampled. These were placed in labelled snap lock plastic bags, and kept in an insulated container until delivery to the lab that afternoon. Samples were sent to AgVita (Tasmanian agent for CIAAF biological laboratory) and analysed for: Glomalin Microbial diversity Microbial biomass AMF was not analysed, on advice from the laboratory, as poppies have been found to have negligible miccorhizal associations. Each plot was also assessed for a range of parameters. This was done by assessing three randomly located 0.5 m 2 quadrats per plot (giving 3 x 3 replicates per treatment) Year 2 On 10 January 2013 soil sampling was done and physical assessments of the trial were made (for all treatments) (refer to Table 2 for comprehensive details on assessments). These assessments were undertaken in the same way as in year 1. The soil samples were analysed for: Microbial diversity Microbial biomass Miccorhizal colonisation Complete nutrient analysis 6

11 Table 2 Description of parameters assessed Parameter How to measure Rating/scoring system used Plant height Poppy growth stage (year 1 only) Measure the overall (average) canopy height Count number of poppies within each growth stage in the 0.5 m 2 quadrat Ground cover Assess % ground cover within the 0.5 m 2 quadrat by eye Root depth (year 2 only)* Earthworms Moisture Dig plants and measure longest root length of a few plants and average Dig one shovel full of soil to 10 cm deep and put in on the bag/tarp. Gently break soil apart and count earthworms Squeeze and feel the soil between fingers to feel how moist it is Average (cm) for the quadrat Number of plants preflowering, hook and capsule and total number % ground cover for the quadrat (included both weeds and crop plants) Average (cm) for a few plants Number/shovel-full Dry (5), slightly moist (4), moist (3), very moist (2), wet (1) Texture Standard texture method Description of soil texture Soil structure Organoleptic Fungal hyphae Dig one shovel full of soil to 10cm deep and put in on the bag/tarp. Use Bill Cotching s scorecard system As you gently break the soil apart to do the structure scores, smell the aroma As you gently break the soil apart to do the structure scores, look for fungal hyphae 0 to 10 scoring system Fresh/earthy/wholesome (1) slight earthy (2) putrid/unpleasant (3) Common (3); Some (2); Few (1); None (0) * Poppy roots were checked for any damage/deformities etc, but an accurate measure of rooting depth was not able to be obtained, due to the size of plants and compaction of the soil making digging to depth not possible. 7

12 3 Results 3.1 Trial assessments Results from physical assessment of trial Figure 2: Average number of poppies per m 2, in compost and control treatment plots (from 11/11/11) Figure 3: Average height poppies in compost and control treatment plots (from 11/11/11) 8

13 The results from November 2011 poppy growth assessment indicated that compost had a positive effect on poppy height (Figure 3), and no effect on density (establishment) of poppies (Figure 2). Figure 4: Ground cover by treatment and year Figure 5: Plant height by treatment and year The results from plant assessments in January 2013 showed no effect of treatment on either plant height or ground cover (Figure 4 and Figure 5), in 2012 there was also no effect of treatment on ground cover. In 2012, on average, poppies in the compost treated plots were significantly taller than those in either the control or compost tea plots (Figure 7). 9

14 Figure 6: Poppy height by treatment (measured 12/12/11) Figure 7: Number of poppies at different growth stages by treatment (measured 12/12/11) Poppies in the compost treatment were more advanced in growth stage than in the other treatments (ie more plants were at the capsule/flower stage in the compost treatment and more were at hook (pre-flowering) stage in the other two treatments) (Figure 7). The taller compost treated poppies may be a function of the difference observed in growth stage (ie compost treated poppies matured more rapidly), rather than indicating that compost treated poppies were more vigorous (and by inference higher yielding). 10

15 There was no effect of treatments on rooting depth of peas in 2012 (Figure 8). Figure 8: Root depth by treatment (no results for 2012) Figure 9: Count of earthworms by treatment and year 11

16 Figure 10: Rating of fungal hyphae in soil by treatment and year In 2012 there appeared to be a positive effect of treatment on earthworm numbers, however this pattern was not repeated in 2013 (Figure 9). However, in 2012 only the difference between the compost and control was significant. In 2013 the earthworm numbers were much lower than Despite the soils being equally moist at the sampling time in both years it may be that the earthworms move lower down in the soil profile later in the season. In 2012, it appeared from the data collected that both compost and compost tea had higher hyphae ratings compared to control (Figure 10). The difference between compost tea and the control appeared to be significant. However, this pattern was not repeated in It is worth noting the very large standard errors for both earthworms and hyphae counts (Figure 9 and Figure 10) indicating the within paddock variability in counting earthworms and hyphae. In 2012 the pattern observed for earthworm numbers was similar to that observed for microbial biomass where there was an increasing trend from control to compost tea to compost (Figure 9 and Figure 14). 12

17 Figure 11: Soil organoleptic assessment by treatment and year In 2012 there was no difference in soil organoleptic rating between treatments, however in 2013 differences were observed with both treatments having a slightly better organoleptic assessment than the control, although this difference was not significant (Figure 11). Figure 12: Soil structure rating by treatment and year There was no effect of treatment or year observed for soil structure (Figure 12) Results from biological assessment of trial There was no difference observed in glomalin between treatments (Figure 13) in Glomalin was not tested for in 2013, based on recommendations given in the year 1 trial report, as it is an expensive test and in a range of other similar trials conducted in 2012 did not show any observable differences. 13

18 Figure 13: Glomalin by treatment (2012 only) In 2012, there was a slight upwards trend from control, to compost tea to compost in microbial biomass, although these differences were not significant (Figure 14). In 2013, there were again increased levels of microbial biomass (and bacteria and fungi) in the compost treatment compared to either of the other treatments (Figure 14, Figure 15 and Figure 16). However, this difference was not significant due to the very high standard errors recorded for the compost treatment. There were major differences observed in microbial biomass between years 1 and 2 (approximately 5 times higher in 2013 compared to 2012). Figure 14: Total microbiology by treatment and year 14

19 Figure 15: Total bacteria by treatment and year Figure 16: Total fungi by treatment and year In 2012, compost had slightly higher microbial diversity than either compost tea or control treatments (Figure 17), although this difference was not significant. In 2013 the compost tea treatment had higher microbial diversity than either the compost or control, although again this was not significant (Figure 17). Compared to the differences in microbial biomass between years, the microbial diversity was reasonably consistent. 15

20 Figure 17: Microbial diversity by treatment and year Mycorrhizal colonisation of plant roots was measured in 2013 (it was not measured in 2012 as poppies do not have mycorrhizal associations). There was a significant difference between all treatments with compost having higher mycorrhizal levels than compost tea which was higher than the control. Figure 18: Mycorrhizal colonisation of pea roots by treatment (data not available for 2012) 16

21 3.1.3 Results from chemical assessment of trial The potential amounts of nutrients applied in the compost, and the compost tea, are negligible in respect to the typical fertiliser regime applied for poppies and ryegrass at sowing. As an example, based on the analysis and rate of compost applied (6m 3 per hectare), the total applied Phosphorus in compost would be in the order of 0.75 kg per hectare compared to typical base fertiliser rates of kg per hectare. Of the macronutrients tested, there was no significant effect of the treatments on phosphorous levels (Figure 19) but all levels are at acceptable levels for cropping. Potassium levels in soil treated with compost were significantly higher than that of the control (Figure 20) but all levels are below optimum levels for cropping. Compost tea was mid-way between, and not significantly different from either of the other treatments. Typically a target range of mg/kg is considered optimal. Calcium also showed similar trends but differences were not significant (Figure 21) while in the case of zinc there was again a significant difference between the compost and control treatment (Figure 22) again with compost tea midway between the control and compost treatments. Figure 19: Phosphorous by treatment Figure 20: Potassium by treatment 17

22 Figure 21: Calcium by treatment Figure 22: Zinc by treatment Figure 23: Boron by treatment There were no significant effects of the compost or compost tea treatments on boron levels in the soil (Figure 23), although the results did indicate some elevation of boron in the treatments compared to the control. 18

23 The effect of the different treatments on sulphur levels was the reverse of the trends observed for other nutrients the control had higher levels than compost tea or compost (differences not significant) (Figure 24). Despite the variance all levels are within the optimal range for cropping (15 20 mg/kg). The extraction methodology analyses sulphate levels not total sulphur, much of which is combined with organic matter. The decrease in sulphur levels maybe due to increased adsorption to organic matter. Figure 24: Sulphur by treatment Sodium levels were also higher in the compost treatment compared to the control (Figure 25), while there were no differences in ph (Figure 27). Typically Sodium levels are observed to increase with increasing ph. The interaction of Sodium with other cations is important and a measure of this interaction is calculation of the Exchangeable Sodium percentage (ESP). The ESP indicated a similar result with the compost significantly higher ESP than the control but no difference between the compost tea and compost or the compost tea and control (Figure 26). Figure 25: Sodium by treatment 19

24 Figure 26: Exchangeable sodium percentage by treatment Total carbon was slightly higher in the compost and compost tea treatments compared to the control however this difference was not significant (Figure 28). There were no differences in carbon to nitrogen ratio or cation exchange capacity between treatments (Figure 29 and Figure 30, respectively). Figure 27: ph by treatment 20

25 Figure 28: Total carbon by treatment Figure 29: carbon to nitrogen ratio by treatment Figure 30: CEC by treatment 21

26 3.2 Compost tea analysis (2012 and 2013) The analysis of Patterdale compost and compost tea from which it was brewed in November 2011 (results presented in Appendix C) showed that the compost was high quality with very high numbers of microorganisms (fungi and bacteria) and a high microbial diversity. However, the compost tea was very different to the compost from which it was made, being bacterial dominated (1.1 g fungi/l, compared to a guide value of 25.3 and 51.1 in compost)) and very low in diversity (diversity indicator of tea 48.8, compared to 66.9 for compost). The analysis of Macquarie Oil compost, Patterdale compost and compost tea in June 2012 (results presented in Appendix D and Table 3) showed substantial differences between the 3 products. Table 3: Summary of microbiological testing of composts and compost tea Macquarie Oil compost Patterdale compost Patterdale compost tea Guide Total microorganisms (g/l) Total bacteria (g/l) Total fungi (g/l) Fungi : bacteria Microbial diversity indicator The Macquarie Oil compost was close to the guide values for all variables measured (except mycorrhizal fungi, see Appendix D). The Patterdale compost was much lower than the Macquarie Oil compost for all variables measured, including nutrients. As in the first year of the trial, the compost tea was again substantially different from the compost from which it was brewed. The compost tea was fungal dominant (opposite to the previous year), with very low overall numbers of microorganisms and very low microbial diversity. 4 Discussion 4.1 Trial results There were some effects of the compost treatment observed on soil biology during the course of the trial, however the significance of the results was reduced by the high standard error of the compost treatment. This may indicate that either the application of the compost is not as even as desirable across the plot/paddock, that there are issues with sampling technique, or analysis of soil biology or a combination of the three. The results from the nutrient testing indicated that a number of nutrients were higher in the compost treated soil than the control (frequently with compost tea mid-way between the two and not significantly different from either). Nutrients which were higher in the compost treatment compared to the control soil were potassium, zinc and sodium. The levels of nutrient applied in the 22

27 compost does not account for these increases, they appear to be a result of transformations in the soil, possibly in respect to increased organic matter breakdown as a result of addition of the compost and associated changes in clay adsorption and mineralisation. As organic matter breaks down sodium is typically released and adsorption capacity of the clay particles can alter affecting detectable levels of elements such as Sulphur. Whilst the changes are statistically significant compared to each other, none of these increases or decreases significantly altered any elemental values outside of acceptable ranges and would have minimal impact on plant growth. The compost treatment also significantly promoted mycorrhizal colonisation compared to both the control and compost tea treatments and the compost tea treatment also had a higher mycorrhizal colonisation compared to the control. The control plots used in this trial design measured the background variation in the variables measured due to environmental factors. This highlighted a very large difference in the biomass of microorganisms between year 1 and year 2 of the trial. Consultation with the specialist soil biology laboratory confirmed that this variation would be extremely unlikely to be caused by analytical error. However, based on their experience with measurement of soil biological factors, the laboratory were able to suggest a number of factors that can cause large variations between samples. These were listed as being, in order of greatest effect to least effect: 1. Sampling micro-location. Samples must be taken in the rhizosphere. There can be approximately 10 to 100 times more microorganisms in rhizosphere soil than nonrhizosphere soil. Depending on the crop, sampling differences of a few centimetres could lead to a big difference in microorganism numbers. 2. Herbicide/other agrochemical application. Applications of herbicides and other agrochemicals can suppress microbial biomasses to a very large degree. 3. Plant growth stage at sampling. Actively growing plants produce more exudates that stimulate soil microbiology, with a maximum around the same time that the plant growth rate is at its maximum. If the growth stages of the plants were different at the two sampling times it could result in a large difference. 4. Environmental conditions. Such as temperature, moisture, nutrients, etc. leading up to the sampling time can make a large difference. The first two factors are expected to have played a large part in the variation observed in this trial. In year 1 the crop grown was poppies and in year 2 peas. The poppies had a less well developed root system than the peas at the time of sampling, meaning that sampling of soil from the rhizosphere is much less likely in poppies than peas. This effect would be exacerbated by chemical applications, which are more frequent in poppies than pea crops. The peas were at an earlier growth stage at sampling (poppies were at early flowering, peas still in the vegetative growth stage). Environmental conditions are unlikely to be responsible for the observed variation, as they were very similar between the two years. 23

28 4.2 Compost tea analysis (2011 and 2012) In 2011, advice was obtained from Joel Williams (BioLife) on methods to improve the fungal diversity in the tea and included the following suggestions: 1. Double check the fish product to confirm if it is an emulsion (heat treated) or a hydrolysate (enzyme treated). A fish hydrolysate is a preferable fungal source; emulsion is preferred by bacteria. 2. Consider halving the entire food recipe. It is a little on the high side and when too much food is added, this can trigger a bacterial bloom in the tea making it harder for fungi to establish. 3. Only a small amount of molasses has been used which is good, but could try removing it from the recipe. 4. Adding some citric acid to the brew to push the ph down a little usually helps fungi. 5. Remove the flour from the tea recipe and use it according to the following instructions instead: 3-5 days (less when warm, more when cool) prior to starting the brew, take the desired 5 kg of compost and spread it into a shallow tray, flatten it out (as if you were mulching the ground in a flat band approx cm thick of compost). With a hand sprayer, mist some water over the compost and mix it through slightly. Then lightly sprinkle some flour over the moist compost and cover it as if you were putting icing sugar on a dessert the surface should be covered white, but only a thin layer, it does not have be piled thickly on top (a few hundred grams should be enough, not the 1 kg). Then cover the tray with a sheet of plastic or similar to keep the moisture (and humidity) in. After a few days you should start to see a fine matt of fungal hyphae growing all over the flour. The fungi have been activated and the compost is now ready to use as you ordinarily would in a compost tea. During this activation stage, check on the tray every day or two to ensure it does not dry out, mist more water over the surface and on the underside of the plastic lid if so keep it moist and humid at all times! 6. A very easy solution (but also comes probably at a greater cost) is to use an NTS product called Dominate (fungi). Of all the playing around with recipe s and temperatures, activations and variable after variable etc, the use of this product was by far the easiest most effective thing I have seen to increase fungal counts (even with poor quality compost). It is not a food source, but an environmental modifier so it makes the brew environment unfavourable for bacteria and favourable for fungi. It is a liquid that is added to the brew water just prior to the food recipe. It is used at a rate of 1L per 100L of water and the brew time should stay around the 24h mark (as you have done anyway). 7. Without knowing the details, but was this tea sampled from the brew tank or out of the growers spray tank nozzle as it was applied? Where possible, the amount of filtration should be kept to a minimum so try to use larger open nozzles and less filtering of the tea at the time of application. 8. Lastly, in relation to the compost itself, usually lowering the manure components and increasing the triticale straw, woodchips and other brown carbon sources should also help (but compost process will take longer). In 2012 the compost tea was again very different in composition to the compost from which it was made (and the two composts were also very different from each other). This again highlights the importance of testing composts and compost teas that are used, as they can vary substantially, 24

29 potentially impacting the results in the field. The lack of response to compost tea measured in this trial, may be more a reflection of the quality of the tea itself rather than compost teas in general. 5 Recommendations Key recommendations based on the results of the trial are: It is important to assess the microbial components of compost tea and not assume that it will reflect the constituents of the compost from which it is made. The compost tea brewing technique should be modified where necessary so that the appropriate balance of fungi to bacteria is achieved and that overall numbers of microorganisms are high and they are diverse enough. It would appear from the results of this trial that getting the compost tea brew right is not straightforward. It is also important to understand the actual composition of the microbiology in compost which is added it can be expensive to use, so being confident of the quality is critical. Results obtained from measuring glomalin do not justify the cost of the test. No clear effect of compost or compost tea was observed on microbial biomass or microbial diversity. However compost did appear to promote mycorrhizal colonisation. Compost treatment was found to result in elevated levels of some nutrients (potassium and zinc) and depressed levels of others (sulphur), and it did not significantly affect soil carbon. The results cast some doubt on the value of one off measurements of biological parameters. However, it is acknowledged that as the understanding of these parameters improves, the value of this testing will also improve. In the meantime replicated plots and multiple tests, which include control plots, are essential in order to be able to determine any meaningful trends or effects of treatments. However, the costs of the analysis may be prohibitive in including measures of biological parameters in replicated trials. Given the costs/effort of applying these treatments in a broad acre situation it is likely that it is more cost effective to encourage soil biology through management practices such as green manure crops, incorporation of stubbles, minimising use of chemical applications, etc and to manage soil nutrients through application of appropriate fertilisers. While compost tea is a cheaper alternative than compost (and therefore might be more readily used in a broad acre situation), it is a lot more difficult to get right. 25

30 6 Appendices Appendix A: Trial map 26

31

32 Appendix B: Macquarie Oil compost analysis Macquarie Oil Compost Analysis August 2011 Ammonium Nitrogen mg/kg 10 Nitrate Nitrogen mg/kg 28 Phosphorus Colwell mg/kg 193 Potassium Colwell mg/kg 920 Sulphur mg/kg Organic Carbon % 2.94 Conductivity ds/m ph Level (CaCl2) ph 5.6 ph Level (H2O) ph 6.5 Total Nitrogen % 0.26 Total Phosphorus mg/kg 703 Total Potassium mg/kg 2537 C:N Ratio 11 27

33 Appendix C: Analysis of compost tea and compost from which it was brewed (November 2011) 28

34 Microbiology Test ABN Tel: Client name Leanne Sherriff Sample Received 17/11/11 Location Tests ordered F1 Crop Compost Tea Agent Agvita Analytical Sample ID Compost Tea Authorised by Ash Martin Sample Date 11/11/11 Analysis no Test F1 - Microbiology Suite (Compost) Test item Biomass (g/l) Ratios Useful indicators Yours Guide Yours Guide Total microorganisms Total:Anaerobic bacteria Total bacteria Fungi:Bacteria Total fungi Microbial Diversity Indicator Prokaryotes Pseudomonas BDL* Mass (g/l) Biomass nutrients (estimated) Actinomycetes Yours Guide Anaerobic bacteria Nitrogen Gram +ve bacteria Phosphorus Gram -ve bacteria Potassium Eukaryotes Sulphur Protozoa Calcium Mycorrhizal fungi Magnesium *BDL = Below Detectable Limit Carbon CIAAF Microbial Diversity Indicator Potential improvement Yours 48.8 Key Good Fair Poor Comments Total microbial biomass was very good, as were biomasses of some other key desirable microbial groups. Fungal biomass was very low, as was Mycorrhizal fungi (VAM). However, fungi are not efficiently cultured in compost tea production systems so this is not unusual. These results were reflected in the very low Fungi to Bacteria ratio. Anaerobic bacteria were elevated, which indicates insufficient aeration during the compost tea production process. Anaerobic bacteria can produce plant-toxic compounds that reduce ghrowth, damage roots and create entry points for root diseases. Pseudomonas were not detected in thsi sample. Pseudomonas are important for soil nutrient solubilisation and disease resistance. Protozoa usually indiacte a mature microbial ecology, so their presence here is a good result. Microbial diversity was fair. Explanations The CIAAF Microbiology Suite test measures the biomass of microorganisms in your actual sample. Other tests may only provide a count of cells or colony forming units, often from plate cultures which only grow about 5 % of known microbes, so they do not measure the full biomass present in your sample. The CIAAF Microbiology Suite test measures living and recently dead (days) microorganisms. Gram +'ve (positive) bacteria tend to be helpful bacteria, while gram -'ve (negative) bacteria tend to be pathogenic (a notable exception is Pseudomonas fluorescens, which is gram -'ve, but helpful under aerobic conditions). Guide values are included as a help, but it is recommended that you compare results with a control test for your sample. Microbiology varies with environment conditions, therefore absolute desirable levels are likely to be inaccurate for your precise environment. Analysis by Creation Innovation Agriculture and Forestry (CIAAF) The information in this report should be used under consideration of particular production conditions. The guide levels are derived from ongoing research carried out by CIAAF. They are intended as a general guide only and do not take into account your specific conditions. Comparison of results with those obtained using other methods may be inaccurate, as accurate interpretation relies on specific sampling and analysis methods. CIAAF and its employees or agents will not be liable for any loss or damage arising from the use of the information supplied in this report. Please seek specific guidance and recommendations from your advisor.

35 Microbiology Test ABN Tel: Client name Leanne Sherriff Sample Received 17/11/11 Location Tests ordered F1 Crop Compost Agent Agvita Analytical Sample ID Compost Authorised by Ash Martin Sample Date 11/11/11 Analysis no Test F1 - Microbiology Suite (Compost) Test item Biomass (kg/m 3 ) Ratios Useful indicators Yours Guide Yours Guide Total microorganisms Total:Anaerobic bacteria N/A 2000 Total bacteria Fungi:Bacteria Total fungi Microbial Diversity Indicator Prokaryotes Pseudomonas Biomass nutrients (estimated) Mass (g/m 3 ) Actinomycetes Yours Guide Anaerobic bacteria BDL* Nitrogen Gram +ve bacteria Phosphorus Gram -ve bacteria Potassium Eukaryotes Sulphur Protozoa Calcium Mycorrhizal fungi Magnesium *BDL = Below Detectable Limit Carbon CIAAF Microbial Diversity Indicator Potential improvement Yours 66.9 Key Good Fair Poor Comments Total microbial biomass was very good, as were biomasses of all other key desirable microbial groups. Protozoa often appear after composts have aged for some time, and their absence is common in commercial compost, so their presence here is a good result. Anaerobic bacteria were absent, which is a good result. Microbial diversity was good to fair. These results indicate that this compost would be a useful amendment to improve the microbial biomass and diversity of soils. Explanations The CIAAF Microbiology Suite test measures the biomass of microorganisms in your actual sample. Other tests may only provide a count of cells or colony forming units, often from plate cultures which only grow about 5 % of known microbes, so they do not measure the full biomass present in your sample. The CIAAF Microbiology Suite test measures living and recently dead (days) microorganisms. Gram +'ve (positive) bacteria tend to be helpful bacteria, while gram -'ve (negative) bacteria tend to be pathogenic (a notable exception is Pseudomonas fluorescens, which is gram -'ve, but helpful under aerobic conditions). Guide values are included as a help, but it is recommended that you compare results with a control test for your sample. Microbiology varies with environment conditions, therefore absolute desirable levels are likely to be inaccurate for your precise environment. Analysis by Creation Innovation Agriculture and Forestry (CIAAF) The information in this report should be used under consideration of particular production conditions. The guide levels are derived from ongoing research carried out by CIAAF. They are intended as a general guide only and do not take into account your specific conditions. Comparison of results with those obtained using other methods may be inaccurate, as accurate interpretation relies on specific sampling and analysis methods. CIAAF and its employees or agents will not be liable for any loss or damage arising from the use of the information supplied in this report. Please seek specific guidance and recommendations from your advisor.

36 Appendix D: Analysis of compost tea and compost from which it was brewed and Macquarie Oil compost (June 2012) 29

37 Microbiology Test ABN Tel: Client name Leanne Sherriff (Mac Frank) Sample Received 06/06/12 Location Tests ordered F1 Crop Compost Agent Agvita Analytical Sample ID Mac Frank - PD Compost Authorised by Ash Martin Sample Date Analysis no Test F1 - Microbiology Suite (Compost) Test item Biomass (g/l) Ratios Useful indicators Yours Guide Yours Guide Total microorganisms Total:Anaerobic bacteria N/A 2000 Total bacteria Fungi:Bacteria Total fungi Microbial Diversity Indicator Prokaryotes Pseudomonas Mass (g/l) Biomass nutrients (estimated) Actinomycetes Yours Guide Anaerobic bacteria BDL* Nitrogen Gram +ve bacteria Phosphorus Gram -ve bacteria Potassium Eukaryotes Sulphur Protozoa Calcium Mycorrhizal fungi Magnesium *BDL = Below Detectable Limit Carbon CIAAF Microbial Diversity Indicator Potential improvement Yours 67.5 Key Good Fair Poor Comments Total microbial biomass was fair. Biomasses of other key desirable microbial groups ranged from fair to good. The Mycorrhizal fungi measured may have been largely ectomycorrhizal (the type that colonise tree roots). The relatively high ratio of Gram +ve (positive) to Gram -ve (negative) bacteria suggests that manure may have been a component of the feedstock. Protozoa often appear after composts have aged for some time, and their absence is common in commercial compost so their relatively high biomass here is a good result and indicator of maturity. The Fungi to Bacteria Ratio was slightly lower than the guide, but this is not a major concern, particularly if the aim was to produce a more bacterial compost. It could be a result of the feedstock materials, for example, manure. Microbial diversity was good to fair. These results indicate that this compost would be a useful amendment to soils. Explanations The CIAAF Microbiology Suite test measures the biomass of microorganisms in your actual sample. Other tests may only provide a count of cells or colony forming units, often from plate cultures which only grow about 5 % of known microbes, so they do not measure the full biomass present in your sample. The CIAAF Microbiology Suite test measures living and recently dead (days) microorganisms. Gram +'ve (positive) bacteria tend to be helpful bacteria, while gram -'ve (negative) bacteria tend to be pathogenic (a notable exception is Pseudomonas fluorescens, which is gram -'ve, but helpful under aerobic conditions). Guide values are included as a help, but it is recommended that you compare results with a control test for your sample. Microbiology varies with environment conditions, therefore absolute desirable levels are likely to be inaccurate for your precise environment. Analysis by Creation Innovation Agriculture and Forestry (CIAAF) The information in this report should be used under consideration of particular production conditions. The guide levels are derived from ongoing research carried out by CIAAF. They are intended as a general guide only and do not take into account your specific conditions. Comparison of results with those obtained using other methods may be inaccurate, as accurate interpretation relies on specific sampling and analysis methods. CIAAF and its employees or agents will not be liable for any loss or damage arising from the use of the information supplied in this report. Please seek specific guidance and recommendations from your advisor.

38 Microbiology Test ABN Tel: Client name Leanne Sherriff (Mac Frank) Sample Received 06/06/12 Location Tests ordered F1 Crop Compost Agent Agvita Analytical Sample ID Mac Frank - MO Compost Authorised by Ash Martin Sample Date Analysis no Test F1 - Microbiology Suite (Compost) Test item Biomass (g/l) Ratios Useful indicators Yours Guide Yours Guide Total microorganisms Total:Anaerobic bacteria N/A 2000 Total bacteria Fungi:Bacteria Total fungi Microbial Diversity Indicator Prokaryotes Pseudomonas Mass (g/l) Biomass nutrients (estimated) Actinomycetes Yours Guide Anaerobic bacteria BDL* Nitrogen Gram +ve bacteria Phosphorus Gram -ve bacteria Potassium Eukaryotes Sulphur Protozoa Calcium Mycorrhizal fungi Magnesium *BDL = Below Detectable Limit Carbon CIAAF Microbial Diversity Indicator Potential improvement Yours 54.9 Key Good Fair Poor Comments Total microbial biomass was very good. Biomasses of other key desirable microbial groups ranged from fair to poor (Protozoa), to very good. The Mycorrhizal fungi measured may have been largely ectomycorrhizal (the type that colonise tree roots). VAM fungi require a living plant host to survive, so their relatively lower biomass from compost is expected and not a concern. Protozoa often appear after composts have aged for some time, and their absence is common in commercial compost, so their relativily low biomass is not a major concern here. Microbial diversity was fair to good. These results indicate that this compost would be a useful amendment to soils. Explanations The CIAAF Microbiology Suite test measures the biomass of microorganisms in your actual sample. Other tests may only provide a count of cells or colony forming units, often from plate cultures which only grow about 5 % of known microbes, so they do not measure the full biomass present in your sample. The CIAAF Microbiology Suite test measures living and recently dead (days) microorganisms. Gram +'ve (positive) bacteria tend to be helpful bacteria, while gram -'ve (negative) bacteria tend to be pathogenic (a notable exception is Pseudomonas fluorescens, which is gram -'ve, but helpful under aerobic conditions). Guide values are included as a help, but it is recommended that you compare results with a control test for your sample. Microbiology varies with environment conditions, therefore absolute desirable levels are likely to be inaccurate for your precise environment. Analysis by Creation Innovation Agriculture and Forestry (CIAAF) The information in this report should be used under consideration of particular production conditions. The guide levels are derived from ongoing research carried out by CIAAF. They are intended as a general guide only and do not take into account your specific conditions. Comparison of results with those obtained using other methods may be inaccurate, as accurate interpretation relies on specific sampling and analysis methods. CIAAF and its employees or agents will not be liable for any loss or damage arising from the use of the information supplied in this report. Please seek specific guidance and recommendations from your advisor.

39 Microbiology Test ABN Tel: Client name Westmore Sample Received 22/06/12 Location Tests ordered F1 Crop Liquid fertiliser Agent Agvita Analytical Sample ID Compost tea trial Authorised by Maria Manjarrez Sample Date Analysis no Test F1 - Microbiology Suite (Compost) Test item Biomass (g/l) Ratios Useful indicators Yours Guide Yours Guide Total microorganisms Total:Anaerobic bacteria N/A 2000 Total bacteria Fungi:Bacteria Total fungi Microbial Diversity Indicator Prokaryotes Pseudomonas Mass (g/l) Biomass nutrients (estimated) Actinomycetes BDL* Yours Guide Anaerobic bacteria BDL* Nitrogen Gram +ve bacteria Phosphorus Gram -ve bacteria Potassium Eukaryotes Sulphur Protozoa Calcium Mycorrhizal fungi Magnesium *BDL = Below Detectable Limit Carbon CIAAF Microbial Diversity Indicator Yours 27.9 Key Good Fair Poor Potential improvement Comments. Note: the guide values shown are for solid anaerobic compost and are shown for comparison only. Total microbial biomass was low. Biomasses of other key desirable microbial groups were also low. Anaerobic bacteria were not detected. Microbial diversity was low. These results indicate that this liquid contains low amounts of active microbes which may be indicative of a shelf-stable liquid product. Anaerobic bacteria were not detected, which indicates that aeration was sufficient during the production process. Anaerobic bacteria produce phytotoxic compounds and denitrify substrates, which are not desirable for fertiliser. Fungi: bacteria ratio was high, which may be related to the number of mycorrhizal fungi found in this sample and the low number of bacteria also present. Explanations The CIAAF Microbiology Suite test measures the biomass of microorganisms in your actual sample. Other tests may only provide a count of cells or colony forming units, often from plate cultures which only grow about 5 % of known microbes, so they do not measure the full biomass present in your sample. The CIAAF Microbiology Suite test measures living and recently dead (days) microorganisms. Gram +'ve (positive) bacteria tend to be helpful bacteria, while gram -'ve (negative) bacteria tend to be pathogenic (a notable exception is Pseudomonas fluorescens, which is gram -'ve, but helpful under aerobic conditions). Guide values are included as a help, but it is recommended that you compare results with a control test for your sample. Microbiology varies with environment conditions, therefore absolute desirable levels are likely to be inaccurate for your precise environment. Analysis by Creation Innovation Agriculture and Forestry (CIAAF) The information in this report should be used under consideration of particular production conditions. The guide levels are derived from ongoing research carried out by CIAAF. They are intended as a general guide only and do not take into account your specific conditions. Comparison of results with those obtained using other methods may be inaccurate, as accurate interpretation relies on specific sampling and analysis methods. CIAAF and its employees or agents will not be liable for any loss or damage arising from the use of the information supplied in this report. Please seek specific guidance and recommendations from your advisor.