During 2006 and 2007, a field trial designed to quantify the effect of two different surface drainage strategies of pasture (hump & hollow and raised beds) on farm productivity, profitability and sustainability was conducted on a commercial farm near Derrinallum. Under the rainfall conditions experienced for the two years of the trial, it is concluded that the use of raised beds for the growing of pastures for grazing has little to offer the sheep industry. On the basis of the data obtained in this trial, it is recommended that the hump & hollow system is the preferred method of surface drainage for sheep grazing systems in this environment and should be promoted in the region. Major findings included:

• In both years, total annual pasture dry matter (DM) yields from the raised bed treatment were substantially less than for the undrained and the hump & hollow treatments.
• In the drought year of 2006 the raised bed treatment grew 37% (2.8 t DM/ha) less while the hump & hollow treatment grew only 7% (0.6 t DM/ha) less than the undrained (total of 7.6 t DM/ha).
• In the higher rainfall 2007 year the raised bed treatment produced 15% (1.6 t DM/ha) less pasture than the undrained. In contrast, the hump & hollow grew 10% (1.1 t DM/ha) more than the undrained (total of 10.7 t DM/ha) in 2007.
• The reasons for the lower than expected pasture yields on the raised beds are speculated to be a combination of low yields in the furrows, poorer plant establishment and density on the beds, and a reduction in the water holding capacity of the soil relative to the other treatments.
• Soil physical health was however considerably better on the raised beds than the other treatments. Aeration porosities at field capacity in November 2007 were a very healthy 16.3% in the raised beds, a moderate 11.8% for the hump & hollow and a poor 7.0% for the undrained.
• No significant differences in ewe or lamb weights at weaning were found between treatments in either year. This was most likely due to the set stocked sheep having pasture on offer in excess of requirements for most of the spring. In 2006 however, the raised beds were stocked at around 1 ewe/ha less due to the lower pasture growth rates.
• From a catchment and general environmental health perspective, the water run‐off results raise some concerns about the environmental impact of growing and grazing pastures on raised beds.
• The raised beds proved to be very effective in removing excess water from the pasture. Over 2007, the raised bed treatment (47.1 mm) had 170% more runoff water than the undrained (17.4 mm) while the hump & hollow (26.7 mm) had 53% more runoff.
• Both drainage treatments had considerably higher concentrations of, and total loads of phosphorus (P) and nitrogen (N) in runoff water. Of particular concern were the losses of 0.5 and 0.4 kg P/ha for the raised bed and hump & hollow treatments respectively compared to 0.1 kg P/ha for the undrained in 2007. For N, corresponding losses were 6.3, 2.1 and 0.9 kg N/ha for the raised beds, hump & hollow and undrained respectively.
• It is recommended that if raised beds are to be used for grazed pastures, then the best practice recommendations developed for raised bed cropping also be applied to pasture.

Both invertebrate pests and beneficials are found in association with chaff in paddocks. However, the species composition depends on the location of the paddock. Paddocks located in the Albany port zone are more likely to have higher densities of pests associated with chaff, whereas paddocks located in the Kwinana East port zone had the least pest densities and highest numbers of seed-harvesting ants associated with chaff.

The most abundant beneficials were weed seed harvesting ants which were found in close association with chaff. As these ants predate on weed seeds and live in holes in the ground, it is unlikely they are using chaff as a refuge, it is more probable that they are foraging in the chaff. This trend presents an opportunity to investigate in greater detail whether seed-harvesting ants provide an economic benefit to growers by consuming weed seeds from HWSC systems left to rot-in-situ.

Pitfall trapping was able to capture a higher diversity of invertebrate species than direct sampling of chaff. As pitfall trapping did not rely on samplers locating an invertebrate, it is more likely to be a more accurate representation of species presence and diversity in a paddock. However, this technique does rely on invertebrates moving and falling into a pitfall trap.

Leaving chaff to rot-in-situ does not affect abundances of pests such as desiantha weevil. However, other pests do use chaff as refuges. For instance, pest beetles, Rutherglen bugs, European earwigs were found in association with chaff. It is unlikely these species are feeding on chaff, but rather are using chaff as a refuge. This survey was not able to determine if long term retention of chaff will increase abundances of these pests.

In 2001 the Rankins Springs CWFS plan to sow lupins across all treatments with the exception of organic treatment, which is considering vetch. The original plan was for barley in 2001, but at the last meeting a motion was passed for lupins to be sown this year to aid soil nitrogen levels.

The Sustainable Land Management Demonstration Sites in the Mallee have been established to demonstrate improved farming practices through a better understanding of crop management and water use to reduce groundwater recharge and soil erosion.

• For this trial, the N-calculator prediction optimised yield and gross margin in Mace wheat.
• In Season N Calculator model predictions were
• Getting mid-season N decisions right can have a significant impact on profitability since optimal top up N rates indicatively increased yields by 480 kg per hectare and net returns by $70 per hectare.
• The value of split N applications was shown and the trial provides more weight to the building confidence that the N calculator can provide real and robust N recommendations that are not in excess of crop requirement and produce maximum or near maximum margin returns from mid-season N applications.

• N Calculator recommendation was accurate for 9 weeks after sowing (WAS) application with additional nitrogen not increasing yeild. The recommendation was slightly below optimumfor 7 WAS.
• Achieving close to the target 10.5% protein indicates that recommended N rates were utilised to optimise growth and yeild and application of N was not deficient or excessive.
• This provides confidence to incorporate the use of N Gauges and the N-calculator to assist in making N application decisions to wheat crops during the season based on the growth status of the crop.
• Summit will continue further testing of the N Calculator under differedt seasonal consitions in the noerthern Wheatbelt and the effect if timining of NVDI assessment and N-Calculator recommendations on yield response to in season N applications.  

• Nuseed Diamond achieved 5 t/ha grain yield from early sowing (watered for germination on 12 April).
• The high yield of Nuseed Diamond was due to its high biomass accumulation and high harvest index. ATR BonitoA was the lowest yielding variety, largely because it accumulated less biomass than hybrid non-TT varieties.
• Split nitrogen application resulted in higher grain yield than all nitrogen applied at sowing or all nitrogen
delayed to the 8-leaf stage.

• Pioneer® 45Y88 (CL) was the highest yielding variety, averaging over 4 t/ha, with Nuseed Diamond and Pioneer® 45Y25 (RR) also achieving high yields.
• Sowing on 5 April resulted in higher grain yield, reduced lodging and lower oil content compared with sowing on 26 April.
• A plant population of 35–56 plants/m2 resulted in higher grain yields than populations of 18 plants/m2 or 68 plants/m2.
• Applying 200 kg N/ha resulted in higher grain yields than 150 kg N/ha when the soil available nitrogen (N) at sowing was 64 kg/ha. Nitrogen rates above 200 kg N/ha resulted in no extra yield.
• Increasing N application rates above 200 kg N/ha reduced oil concentration.
• Crop lodging increased with plant populations above 35 plants/m2 and N rates above 150 kg N/ha.

• Correct varietal selection and optimal agronomic management can result in irrigated wheat yields of over 10 t/ha.
• LongReach CobraA, LongReach TrojanA and BeckomA were the highest yielding varieties.
• Delaying nitrogen fertiliser application by applying the greatest amount at booting was shown to improve grain protein concentration and reduce lodging compared with applying more nitrogen at sowing.
• A plant population of 120 plants/m2 was shown to yield more than higher plant populations whilst also minimising lodging.

In this trial we observed no response to the non-nitrogen test products, either on the low or high fertilizer at seeding treatments.  However we cannot say that they will not work under other site, season and management conditions.  Unfortunately the promoters can rightly say that we did not give their product the best opportunity to perform and so it was an invalid test.

Such a reply has implications for the promoters rather than the testers. The promoters have an obligation to state under what conditions they expect their product to work and those conditions  have to be readily recognized by potential local users. It is not good enough to list a range of processes which the product “improves” or even to quote circumstances from elsewhere where the product has worked. Any new product (and agronomic practice for that matter) has to be  extensively tested under local conditions so that the promoters can say what the chances of success are if used by local growers.

We, the testers are able to state that the product did not work under our conditions and in the Popper sense of “falsification” have disproved any statement about how generally useful the product might be. That is, 100% of our observations say it does not work, but that is hardly useful. We could have had a drought year and nothing would have worked. We could have been wiped out by      frost or we may have chosen a site with the wrong levels of fertility. We did not test across a full range of conditions and so have too limited information for invalidating the all claims made for the products. This problem is equally true for validation by the product developers.

Products MUST be tested across a wide range of local conditions before it can be promoted with confidence to the broader agricultural community.

In short, any new product (or agronomic practice) requires a major investment in validation trials which are ranged across the full set of management, site and season conditions experienced in the new environment. Otherwise, general promotion of those products should not be believed until such work has been done.

• From the 10% challenge came a feast of ideas, usually with one or two key focus points considered valuable to the farming operation, with farmers agreeing with or discussing other ideas as they were shared within the groups.
• The information arising from these sessions has been presented at farmer meetings for local groups to discuss in relation to their own farming systems. Further development and extension of this work and ‘rules of thumb’ will be investigated with the discussion
• groups and delivered at local farmer meetings.

There are substantial benefits from GM herbicide tolerant canola when compared with alternative non-GM weed control systems. These include more effective weed control, reduced pesticide use, reducted use of cultivation, improved yields, reduced risk of herbicide resistance and a reduction in the environmental 'footprint'.

Topdressing pulses with nitrogen does not pay; inoculation does. Nitrogen topdressing of pulses resulted in little or no net growth or yield benefit. Inoculating pulses is most effective if the soil is moist and if residual soil nitrogen and soil rhizobia populations are low. The current study indicated that a return on investment of up to $60 can be achieved from the inoculation of chickpeas in the absence of soil rhizobia.

The results of this study suggests:

• Whilst the streaming of UAN modestly reduced annual ryegrass N percentage in the tissue, no difference in annual ryegrass biomass or seed production was evident.
• Nitrogen placement did not affect Wheat biomass accumulation (NDVI results), however modest differences in Canopy closure percentage existed. UAN rate and timing however had a greater effect on wheat biomass (NDVI results and wheat biomass cut) and percent canopy closure.
• UAN rate, UAN timing (plus interaction of UAN timing and placement) were found to have significantly affected Radiation interception of the crop in the absence of weeds.
• Nitrogen placement affected the yield and protein content of the grain produced.

Whilst the streaming of UAN modestly reduced annual ryegrass (ARG) N percentage in the tissue, no difference in annual ryegrass seed production was evident. Due to the dry conditions in 2019, the application of supplementary UAN did not significantly increase wheat canopy closure or yield. Interestingly, UAN placement did affect the total nitrogen uptake in the ryegrass population, potentially increasing ARG competitiveness. Banding UAN to the crop row was found to increase ARG N uptake. As seeding systems provide herbicide free bands on otherwise herbicide treated soil for safe wheat establishment it was found that the majority of ARG emerged from these crop rows. Concentrating N applications to these regions may have inadvertently increased the N uptake in ARG. This study was conducted in York over the 2018 and 2019 seasons. A multi- environment trial analysis for the combined data to be completed.

•  Use the tools – they are easy to use and real eye opener on what acidity can be costing you.
• Significant yield improvements have been seen when cropped paddocks are limed.
• Make liming a part of your annual program. 
   

A harvest-time knockdown to kill summer weeds has been shown to conserve significant soil moisture prior to seeding in a series of trials across the eastern wheatbelt this year.

• Wider row spacings (300mm vs 200mm) significantly reduced yield when averaged across three wheat varieties and two nitrogen timings. Wider rows reduced crop income in excess of $100/ha.
• The cultivar (variety) grown was just as important as row spacing in determining yield. When averaged across the different row spacings and nitrogen timing treatments, Kellalac yielded 4.61t/ha, Bolac 5.12t/ha and Beaufort 5.72t/ha.
• Tiller counts were significantly less when moving to the wider row spacing widths. At the 200 mm row width, Beaufort had significantly fewer tillers/m2 than Kellalac, which in turn had significantly fewer tillers than Bolac. When the row spacing increased to 300mm, both Kellalac and Bolac had a significant reduction in tillers, while counts for Beaufort did not drop significantly. Kellalac had the fewest number of tillers at the wider row spacing.
• Row widths of 200mm with nitrogen applied at GS00 & GS31, tended to give higher yields (5.30t/ha & 5.33t/ha respectively) when compared to a row spacing of 300mm with nitrogen applied at GS00 (5.09t/ha) & GS31 (4.88t/ha).

• In 2015, two spring irrigations produced the highest wheat grain yield (7.61 t/ha), but one irrigation provided the highest water use efficiency (1.7 t/ML).
• Ponding irrigation water for 48 hours to induce waterlogging did not reduce grain yield in this experiment, but increased water use and reduced water use efficiency by 25%.
• If the number of spring irrigations is limited, it is important to find a balance between irrigating before significant moisture stress occurs and ensuring adequate moisture is available during flowering.
   

• Suntop was the highest yielding variety (4.48 t/ha).
• Lancer achieved high protein, high test weight and low screenings at all nitrogen application rates.
• Grain yield increased as nitrogen application rates increased, but there was no significant increase in yield above 20 kg N/ha applied nitrogen.
• Applying 160 kg N/ha resulted in a yield decrease.

For results and discussion please see the attached trial report.

Rhizobium inoculation improved faba bean yields by 9-30% above uninoculated plants. Higher rates of rhizobium inoculum show a trend to further increase yield though this was not significant. Rhizobium inoculation should be considered as cheap insurance against conditions not favourable to nitrogen supply, particularly during winter.

• Early sown (9 April) Pioneer 45Y88 (CL) yielded similarly to later sown (20 April) Pioneer 45Y88 (CL) and Hyola 575CL.
• The irrigation treatment that stored 20mm plant available water did not increase grain yield or oil concentration.
• The maturity biomass was higher from the later sowing date, but the harvest index was slightly higher from the early sowing date.

 

• Variety phenology and sowing date need to match to avoid plants flowering and podding during periods of severe frost. The highest yield in 2017 came from the 6 April sowing of the long season varieties Archer and ATR WahooA that flowered in early August.

• ATR Stingray and Nuseed® Diamond flowered earlier than the optimum start of flowering (OSF) date (28 July) from both the 6 April and 20 April sowing dates with significant frost damage incurred at both sowing dates.

• Canola varieties have the ability to recover from severe frost damage where soil water is not limited.

• Cereal stubble should be thought of as a source of C for microbes, not as a source of N for crops. In the Mallee under no-till systems, only 1-2% of the N requirement of wheat crops is derived from the previous wheat stubble.
• N tie-up in cropping soils is only a temporary constraint as the immobilised N will be released through microbial turnover, generally later in the crop season in spring.
• N tie-up by cereal residue is not just a problem following incorporation – it also occurs in surface-retained and standing-stubble systems.
• Management of tie-up is reasonably straightforward – supply more N (5 kg N for each t/ha of cereal residue) and supply it early to avoid impacts of N tie-up on crop yield and protein.
• Deep-banding N can improve the N uptake, yield and protein of crops, especially in stubble-retained systems.

• Varietal selection again proved to be the major factor in achieving higher wheat yields in the second year of experiments in irrigated wheat production at Leeton.
• CobraA was the highest yielding variety in this experiment but CorackA, SuntopA and the durum breeding line 280913 also performed very well.
• Correct nitrogen timing significantly increased grain yield, grain protein and significantly reduced lodging.
• Managing plant population also significantly reduced lodging

The practical implications of harvest weed seed control are a more resilient farming system with some insurance against further resistance evolution. The combination of effective herbicide use, plus harvest weed seed control techniques has been shown to reduce and maintain weed populations at very low densities. In cropping systems, low weed densities, regardless of their herbicide resistance status, allows flexibility in crop choice, seeding time and herbicide use. This flexibility provides growers with the capacity to readily adjust farming practices in tune with seasonal and market considerations.

• A series of field experiments was conducted on the Eyre Peninsula to examine the effects of herbicides on the nutrition of treated crops.
• Experiments investigating the effect of metsulfuron-methyl and chlorsulfuron on crop performance are reported here.
• The parameters measured were shoot growth, tissue nutrient concentration and grain yield.
• Application of metsulfuron-methyl to manganese-deficient barley and chlorsulfuron to zinc-deficient wheat crops caused yield penalties by intensifying the respective deficiencies.
• Yields were not affected when the herbicides were applied to plots which were trace element adequate.
• The consequences are that if adequate fertiliser regimes are not employed in the field, yield benefits due to weed control may be eroded by losses due to aggravated micronutrient deficiencies.

1. Most farming systems extract more nutrients than are supplied by common fertilisation strategies.
2. Increasing the frequency of legumes doesn’t necessarily reduce nitrogen inputs required across the crop sequence and increases export of potassium.
3. Higher fertiliser application has maintained higher soil mineral nitrogen levels but rarely increased grain yield or total system nitrogen use.

The results suggest using nitrogen and/or increasing sowing rates will increase drymatter available for grazing at late tillering but if grazed these treatments will have a positive impact on grain yield.

• Increasing siphon pipe diameter used for flood irrigation, from 42 mm to 63 mm halved irrigation time, reduced the amount of water applied per irrigation, and increased cotton lint yield and lint quality.
• The longer irrigation time increased soil water content for up to a week post irrigation, and likely led to waterlogging effects on cotton plant growth.
• The maximum daily nitrous oxide (N2O) emissions occurred in response to the first irrigation event after pre-plant nitrogen (N) application and continued for more than a week after irrigation.
• The highest N2O emissions in each plot came from the non-irrigated side of the plant bed where surface soil nitrate concentrations were also highest – despite pre-plant N fertiliser being applied evenly to both sides of the plant bed.
• Postharvest, excess soil nitrate was found to depth in the non-irrigated side of the plant bed, indicating that nitrate moved both sideways and downwards during the season.
   

• The high input pasture treatment provided the opportunity to carry 8 DSE/ha with an estimated gross margin of $240/ha, however it was unable to utilise plant available water above 50% of potential water use efficiency (WUE).

• It appears that once disease suppression is achieved in low rainfall farming systems of upper EP and inoculum levels are low, it is quite robust and will be maintained despite systems with substantially different amounts of mineral N.
• Fallow, Medic/Fallow and Peas all lowered rhizoctonia inoculum levels in 2010, and Fallow and Peas lowered levels in 2009.
• Continuous cereals produced the highest inoculum levels but all levels were low at this site.
• Even high mineral N (118 kg N/ha) in the top 60 cm (measured in April after spraytopped medic) did not increase Rhizoctonia patches in 2010.
• Trichoderma fungus and the beneficial PEM microbes are present in the MAC N12 system.

• Soil mineral nitrogen (N) values were low across all sites, which was indicative of the wet seasonal conditions and high nitrogen losses.
• There were no significant differences in mineral nitrogen values between the stubble treatments due to high variability (likely due to transient waterlogging across the sites).
• The project has been extended to enable the research to be repeated during 2017.

• While significant differences in mineral nitrogen (N) values were measured between stubble treatments, these differences were small and unlikely to elicit a plant growth response.
• No consistent trends were observed between trial sites.
• Delayed plant growth and development under no-till stubble retained (NTSR) systems in the Riverine Plains region is unlikely to be due to decreased mineral nitrogen availability as a result of immobilisation.

The data from this trial supports the theory that an early sowing date will increase DM and total N fixation in Percy and Morava.

• Summer weeds use significatn amounts of stored soil water.
• The long-term impact of summer weeds amounts to a loss in production of 1t/ha in cereal yield in the southern Mallee.
• In a changed climate scenario, where our region is likely to receive more summer rain at the expense of spring rain, the impact of summer weeds on potential crop yield is likely to increase.

• Nitrogen fertiliser management influences crop nitrogen uptake at defoliation and cotton lint yield
• Irrigation management did not influence crop nitrogen uptake at defoliation, but significantly influenced cotton lint yield.
• The apparent nitrogen fertiliser recovery was 46% where the optimum fertiliser nitrogen rate was applied
• Seed nitrogen concentration and nitrogen removal was influenced by nitrogen fertiliser application rate, but the effect was not consistent with rate.

• For a wheat crop with an average yield of 4.5–5t/ha, increasing the rate of nitrogen (N) applied (40 and 80 extra kilograms of nitrogen per hectare above the farm standard) significantly increased dry matter (DM) accumulation, crop height and final yield of first wheat following canola.
• Applying a plant growth regulator (PGR) (Moddus + chlormequat) reduced crop height by 3cm and significantly decreased DM production.
• A small, non-significant yield reduction was measured with PGR application, which was similar to that observed during 2014, when yields were in the 5–6t/ha range. Conversely, during 2015, there was a positive yield effect of 0.1t/ha, when average crop yield was approximately 3t/ha.
• Although differences were small, the PGR application significantly increased screenings and decreased test weight, results that are not in line with the effects observed during 2015.
• After three years of trials there is no evidence to suggest PGR application has delivered any positive yield effects or consistent quality effects.
• In all three years of trials, PGR application showed a trend to reduce DM, which was significant in 2016.

• In two first-wheat trials yielding 4.5-5.0t/ha, the application of a plant growth regulator (PGR) delivered no benefits in terms of yield or grain quality.
• The PGR application did not interact with additional nitrogen applied in terms of yield or quality.
• The impact of PGR application on crop height was greater than the impact of nitrogen timing; however, the differences in height were small.
• The grower-applied nitrogen at Redlands, at a rate of 75kg N/ha, and at Yarrawongs at a rat eof 100kg N/ha, were shown to be optimum in terms of yield and quality, with no extra yield or protein resulting from the higher nitrogen application rates with Corack and Wedgetail.

• With an average yield of almost 3t/ha, increasing the rate of nitrogen applied (40 and 80 extra kg N/ha) did not affect dry matter (DM) accumulation, crop height or fianl yield of first wheat following canola.
• Applying a plant growth regulator (PGR) decreased crop height, but did not influence DM or grain yield.
• Although differences were small, PGR application significantly decreased screenings and increased test weight.
• Applying the PGR also decreased crop reflectance, measured as normalised difference vegetation index (NDVI) during stem elongation (GS39); a result also observed during 2013 and 2014.
• The lower NDVI readings suggest PGR altered greeness of the crop canopy or the orientation of the leaves, decreasing crop reflectance.

• While machinery ownership and management has its complexities, being aware of some of the aspects that directly impact upon its economic efficiency is a step in the right direction. Consideration of work rate efficiency and timeliness versus over-capitalisation and ultimate returns achieved by the system is very important.
• The Farming Systems Project has identified that the cost profile of the different farming systems from most to least costly is, Fuel Burner, Hungry Sheep, Reduced Till and Zero Till.

• Select crops best adapted to the soil and climatic conditions of your region; faba bean is the pulse crop best adapted to soils prone to waterlogging.
• Avoid soils with acidic subsurface layers and/or shallow topsoil that limit root development and impermeable subsoil that restrict drainage.
• Test soil pH at 5cm intervals to a depth of 20 cm, to detect subsurface acidity.
• Select paddocks at least two years before sowing acid-sensitive crops to allow time for applied lime to react and increase soil pH, if required.
• Sow early in the recommended sowing window for your location, to encourage effective nodulation, early vigour and biomass accumulation before the onset of cold, wet conditions.

Executive summary

Recently interest in the role of renovation cropping in the farming systems of the Western Australian wheatbelt has increased.  It has been proposed as a means of addressing the apparent decline in soil quality in some intensively cropped areas and the increased incidence of herbicide resistance. 

Renovation cropping involves either turning a crop into the soil at flowering or cutting the crop and leaving it on the soil surface.   This is done to maximise the amount of organic matter added to the soil and to control weeds most effectively.  In the Western Australian wheatbelt the focus has been on using pulses, although a range of crops can be used.  The pulse phase of a rotation is favoured as pulses improve the nitrogen status of the soil. In addition the returns to pulses are lower relative to cereals and canola, so the forgone profit in the year of renovation cropping is lowest.

Renovation cropping leads to changes in soil conditions that persist for at least the following season.  It reduces weed numbers in the following crop by reducing seed set, increases the availability of nutrients and may improve soil structure.  Lower weed numbers reduce the carry-over of root diseases thus providing a disease break for the following cereal crop.  Recent trials have shown likely yield increases of 20-30% above those after a pulse crop and increased grain protein levels in the following cereal.

The main cost of green manuring is the income lost by sacrificing grain production.  The loss in income plus any additional costs associated with soil renovation need to be recouped in the following season(s).  Therefore the income from the yield increase(s) in the subsequent year(s) needs to be equal to or greater than the total costs of renovation, including the income forgone.

Despite the increase in interest in renovation cropping, no comprehensive economic analysis has been undertaken to determine its role in Western Australian farming systems.  This study investigates circumstances under which renovation cropping is likely to be profitable and estimates the needed increase in farm profit, given the variability of yields that result from seasonal influences.

To investigate the consequence of risky yields historical rainfall data was used to generate yield distributions for different rainfall zones, soil types and crops.  The yield distributions were used as input to a simulation model to determine the distribution of income, resulting from renovation cropping, in a lupin:wheat:wheat rotation.  The mean yield boost resulting from renovation cropping was estimated to be 3% based on trial results (F. Hoyle, pers. comm.). 

The results of the analysis showed that there is a 30-40% chance of increasing profit if yield is increased by 30% on average.  However, the results were very sensitive to the average increase in yield.  The probability that profit will be increased was halved when yield boost was reduced to 20%. 

The yield increase required to make renovation cropping profitable can vary between 100% under the worst case and below 10% under the best case.  The variability depends on grain prices, grain yield in the renovation phase (if a commercial crop had been was harvested), and the cost of renovation and grain yields in the following crop phase.

The likelihood that profit will be increased depends largely on minimising income forgone relative to the increase in income in the following years.  Therefore green manuring will be most profitable when done in years when the grain yield of the pulse crop is low, and/or when the following cereal yield is very high. 

Weather forecasts are not yet sufficiently developed to predict potentially good years over 12 months ahead, so renovation needs to be undertaken in poor years to maximise the chances of increasing profit.

Identifying poor yielding years prior to renovation does present some difficulty although weather forecasts may improve the chances of undertaking renovation in the 'right' year.  .  Also yield potential is determined directly by biomass of the crop, so this may be used as an early indicator of yield.  Where waterlogging or disease has caused low vegetative growth, resistant weeds are widespread in a paddock, or where frost has damaged the crop green manuring is more likely to be a profitable option. 

This suggests a role for tactical use of renovation cropping so that it is undertaken in years where the forgone income is minimised (i.e. it is done in poor yielding years).  The results of the analysis show that only small yield increases in the following cereal crop are necessary to break even in these circumstances. 

The analysis highlighted gaps in the knowledge of the impact of renovation cropping that may be important for more comprehensive economic analysis, or information that may improve the grower’s ability to undertake the practice profitably.  Further research into green manuring could include:

• Determining whether the profitability of green manuring can be increased using long term weather forecasts.  Improving the estimates of the probability of achieving different yields may allow farmers to renovate soils in years that have lower risk.
• More information on the effects of green manuring on yield and protein for different crops under different conditions is required to better assess the economic advantages of green manuring
• The profitability of green manuring relative to other methods of improving sustainability of cropping also needs to be addressed.

 

Executive summary

Recently interest in the role of renovation cropping in the farming systems of the Western Australian wheatbelt has increased.  It has been proposed as a means of addressing the apparent decline in soil quality in some intensively cropped areas and the increased incidence of herbicide resistance. 

Renovation cropping involves either turning a crop into the soil at flowering or cutting the crop and leaving it on the soil surface.   This is done to maximise the amount of organic matter added to the soil and to control weeds most effectively.  In the Western Australian wheatbelt the focus has been on using pulses, although a range of crops can be used.  The pulse phase of a rotation is favoured as pulses improve the nitrogen status of the soil. In addition the returns to pulses are lower relative to cereals and canola, so the forgone profit in the year of renovation cropping is lowest.

Renovation cropping leads to changes in soil conditions that persist for at least the following season.  It reduces weed numbers in the following crop by reducing seed set, increases the availability of nutrients and may improve soil structure.  Lower weed numbers reduce the carry-over of root diseases thus providing a disease break for the following cereal crop.  Recent trials have shown likely yield increases of 20-30% above those after a pulse crop and increased grain protein levels in the following cereal.

The main cost of green manuring is the income lost by sacrificing grain production.  The loss in income plus any additional costs associated with soil renovation need to be recouped in the following season(s).  Therefore the income from the yield increase(s) in the subsequent year(s) needs to be equal to or greater than the total costs of renovation, including the income forgone.

Despite the increase in interest in renovation cropping, no comprehensive economic analysis has been undertaken to determine its role in Western Australian farming systems.  This study investigates circumstances under which renovation cropping is likely to be profitable and estimates the needed increase in farm profit, given the variability of yields that result from seasonal influences.

To investigate the consequence of risky yields historical rainfall data was used to generate yield distributions for different rainfall zones, soil types and crops.  The yield distributions were used as input to a simulation model to determine the distribution of income, resulting from renovation cropping, in a lupin:wheat:wheat rotation.  The mean yield boost resulting from renovation cropping was estimated to be 3% based on trial results (F. Hoyle, pers. comm.). 

The results of the analysis showed that there is a 30-40% chance of increasing profit if yield is increased by 30% on average.  However, the results were very sensitive to the average increase in yield.  The probability that profit will be increased was halved when yield boost was reduced to 20%. 

The yield increase required to make renovation cropping profitable can vary between 100% under the worst case and below 10% under the best case.  The variability depends on grain prices, grain yield in the renovation phase (if a commercial crop had been was harvested), and the cost of renovation and grain yields in the following crop phase.

The likelihood that profit will be increased depends largely on minimising income forgone relative to the increase in income in the following years.  Therefore green manuring will be most profitable when done in years when the grain yield of the pulse crop is low, and/or when the following cereal yield is very high. 

Weather forecasts are not yet sufficiently developed to predict potentially good years over 12 months ahead, so renovation needs to be undertaken in poor years to maximise the chances of increasing profit.

Identifying poor yielding years prior to renovation does present some difficulty although weather forecasts may improve the chances of undertaking renovation in the 'right' year.  .  Also yield potential is determined directly by biomass of the crop, so this may be used as an early indicator of yield.  Where waterlogging or disease has caused low vegetative growth, resistant weeds are widespread in a paddock, or where frost has damaged the crop green manuring is more likely to be a profitable option. 

This suggests a role for tactical use of renovation cropping so that it is undertaken in years where the forgone income is minimised (i.e. it is done in poor yielding years).  The results of the analysis show that only small yield increases in the following cereal crop are necessary to break even in these circumstances. 

The analysis highlighted gaps in the knowledge of the impact of renovation cropping that may be important for more comprehensive economic analysis, or information that may improve the grower’s ability to undertake the practice profitably.  Further research into green manuring could include:

• Determining whether the profitability of green manuring can be increased using long term weather forecasts.  Improving the estimates of the probability of achieving different yields may allow farmers to renovate soils in years that have lower risk.
• More information on the effects of green manuring on yield and protein for different crops under different conditions is required to better assess the economic advantages of green manuring
• The profitability of green manuring relative to other methods of improving sustainability of cropping also needs to be addressed.

 

There was a significant response to all nitrogen applications.

In an irrigated trial on Mackellar (feed wheat) at Hagley, Tasmania, plot yields ranged from 6.6 – 9.4 t/ha depending on the level of nitrogen and fungicide input. There was a significant response to nitrogen application, with an optimum that varied from 60 ‐120 kg/ha depending on whether fungicide was applied. There was a significant yield interaction (P=0.003) between the amount of applied nitrogen and the level of fungicide input, whereby the higher the level of applied nitrogen the greater was the need for fungicide input. Without fungicide application at stem elongation the optimum nitrogen input for the crop was 60 kg/ha N; however with fungicide application it was at least 90 kg/ha N. There was a significant increase in grain protein associated with increasing nitrogen level in the range of 60 ‐120 kg/ha N and a significant increase in protein associated with fungicide application.

Six varieties of canola were tested to compare their responsiveness to urea. The varieties selected had different growth patterns, and the slow growing varieties such as the TT types showed a similar response in growth to the other more vigorous types. In this experiment, urea did not increase yield of any of the varieties tested, but oil contents fell for five of the six varieties with added urea, with ATR Hyden the exception. Given the poor yield response, little can be directly interpreted from these results, although it is reasonable to conclude that higher urea rates are less profitable with lower yielding types or on sites with low yield potential.

The SOI phase signal for April-May (available on the last day of May) and subsequent monthly phases can provide useful information on the likelihood for rainfall for the rest of the season. It can be a very useful tool for assessing the risk of topdressing nitrogen fertiliser (especially if it is used in combination with other indicators such as potential of the crop; decile trend and stored soil moisture).

• There is little to be concerned about from implementing a strategic tillage provided:
  • That it is not frequent, say less frequent than once every five years based on the above.
  • That we consider the well-known risks for erosion such as slope, groundcover, and current weather, and the soil moisture at the time of the proposed tillage. Hence, we suggest leaving the tillage as late as possible so as to avoid the chance of erosive rainfall between tillage and crop establishment.

• Zinc efficient and inefficient wheat cultivars were grown in soil cores in the glasshouse.
•  The calcareous soil had low micronutrient levels and high pH and boron.
• Although cultivar Gatcher produced 47% more dry weight of tops and double the root length density of cultivar Excalibur at maturity, cultivar Excalibur was much more efficient in terms of zinc uptake by roots and sevenfold more efficient than cultivar Gatcher in partitioning zinc to grain.

• Zinc-efficient (Excalibur) and inefficient (Gatcher) wheat cultivars grown in calcareous subsoil with low micronutrient levels, high pH and B.
• Treatments were +/- basal nutrients (exc Zn) and +/-Zn.
• Gatcher produced 47% more DM tops and double the root length density of Excalibur by maturity Excalibur was far more efficient in Zn uptake and seven times more efficient than Gatcher in partitioning zinc to grain.

There was no yield benefit using bio-degradable polymer film on late sown barley and field peas.

• New fodder shrub species have been successfully trialed in the UN.
• Perennials, including fodder shrubs will increase pasture production on poor, degraded soils.
• Grazing animals require a balanced diet with a variety of pasture species to ensure the correct balance of energy, protein and minerals.
• High stocking pressure for short periods is necessary to maximize pasture production of both the fodder shrubs and inter-row pasture.

• Poor growth of flax observed on "Bay of Biscay" (black clays) in Auburn area of South Australia.
• But soil type patchy through paddocks.
• Agricultural zinc sulphate was cheaper and as effective as calcined zinc in correcting the problem.

Results from the initial establishment season have again confirmed the ability of hardseeded legumes to grow and set seed under adverse seasonal conditions.  The value of indeterminate pattern of growth in facilitating additional seed set was also shwon with biserrula where following late spring rain, an additional round of seed set resulted in a more than doubling of overall seed production.Bladder, with a slightly deeper root system, and gland clover which is early maturing also showed b etter capacity to produce seed in challenging condition s compared to subterranean clover.  With production of a seed bank critical for pasture performance  in subsequent years, the performance of hardsseded legumes was very encouraging.

• Across three years addition of trace elements and fluid fungicide in-furrow did not provide increases in emergence, tillering or final yield - although this contradicts what other farmers have reported.
• Liquid N at sowing can improve crop emergence and early vigour, especially under dry conditions .
• Full liquid systems did not provide a profit benefit (due to higher input costs) even where they did provide increased yield which was not in all years.
• Recommendation most likely to provide higher returns for this area will be an in-furrow fertiliser system that incorporates some elements of liquid nitrogen and phosphorus fertiliser ,trace elements, fungicides and granular phosphorus and nitrogen fertiliser.

• There was rapid change in soil pH at this site in the first few years following the establishment of this trial.

• Despite the initial changes in soil pH, there were no positive grain yield responses between 1996-1999.

• In the 2000 wheat crop, there was a negative response to 2t/ha in 2000. 

• There has been a dramatic decline in soil pH across all treatments since 2000, despite a total of 4t/ha of lime being applied across the site (two applications of 2t/ha in circa 2009 and 2013.

• The source of the subsequent applications of lime applied by the farmer is unknown

In this 2014 trial at Kojonup-West:

• Canola grain yield and gross margins were more dependent on nitrogen rates than the application timings.
• There was no effect of delayed nitrogen application on grain yield or gross margins up to 100 kg N/ha.
• At 125 kg N/ha, a significant yield and gross margins reduction was observed when nitrogen was applied as a 3-way split (50 kg within 8 weeks, 50 kg/ha at 12 and 25 kg/ha at 16 weeks after seeding) compared to when all of the nitrogen was applied within 8 weeks of seeding.

• Canola grain yield and gross margins were more dependent on nitrogen rates than the application timings.
• Delaying application of nitrogen after 8 weeks reduced canola yield.  The reduction was greater the higher the proportion of total applied N delayed.  
• Hyola 404RR produced significantly higher grain yield and oil than ATR Wahoo, but similar gross margins.

• We observed no significant differences in grain yield (GY) between any treatments due to low yield potential and reasonable soil nitrogen (N) levels at seeding.
• Timing of N application had no effect on GY. This is consistent with last years’ results at Wubin.
• Canola oil percentage decreased as N rate increased. High rates of N reduced oil significantly, consistent with last year at Wubin.
• The higher the rate of N the more rapidly oil percentage reduced, consistent with last year at Wubin.
• Gross margins (GM) decreased as N rates increased; all GM figures are negative due to poor GY, however, Sturt performed better than Pioneer 43Y23RR due to the higher seed costs associated with Roundup Ready (RR) seed.

• There were significant differences in grain yield (GY) between treatments (N kg/ha and timing), however, GY was particularly low in all treatments. 
• Total nitrogen (N) increased GY significantly up to 30kg N/ha.
• Canola oil percentage decreased as N rate increased. High rates of N reduced oil significantly.
• Applying N late (12 weeks after sowing (WAS) reduced canola oil percentage, however, not significantly.
• Gross margins decreased as N rates increased, but all gross margins (GM) were negative due to poor GY. Sturt had better gross margins than Pioneer 43Y23RR due to the higher seed costs associated with RR seed.
• Pioneer 43Y23RR produced higher GY at all rates and timings of applied N other than 10N seeding and 20N 12WAS.

• Canola responded to N applied as late as 12 weeks after seeding but not as much as to N applied at 4 or 8 weeks.  Hyola 404 RR and CB Telfer responded similarly in terms of yield.
• Nitrogen reduced oil %, and late N reduced it more than early N.  Oil was more sensitive to applied N in CB Telfer than in Hyola 404 RR.
• Grain yield continued to respond to 100 kg N/ha but the highest gross margin was at 75 kg/ha in Hyola 404 RR and at 100 kg/ha in CB Telfer.

In this 2013 trial;

• Canola grain yield responded positively to nitrogen application.
• Canola oil content responded negatively to nitrogen application.
• Therefore a wide number of treatments produced equal highest gross margins.
• The lowest rate of nitrogen treatment to produce maximum returns was 25 kg N/ha applied 4 weeks after sowing.
• We found treatments applied 12 weeks after sowing when the canola was flowering produced. similar results to applications applied at 8 weeks after sowing – which is the industry norm.
• Hyola 404RR produced higher oil but equal yield and gross margins to CB Telfer.

In this 2013 trial

• Time of nitrogen application had a minor effect on grain yield, oil and gross margins

applying 50 kg N/ha in a split application with 25 kg N/ha applied at seeding and 25 kg N/ha applied 12WAS was the equal of any other treatment.

• Both CB Telfer and Hyola 404RR responded similarly to nitrogen rate and timing of application.

Consequently due to lower seed costs, CB Telfer produced on average higher gross margins of $415/ha compared to $307/ha for Hyola 404RR.

• Canola grain yield increased with nitrogen application up to 50 kg N/ha
• Timing of nitrogen application had no effect on grain yield
• Canola oil decreased as nitrogen rate increased
• Applying nitrogen late (12 weeks after sowing) reduced oil%, but only if total N applied was 50 kg/ha
• Overall gross margins were similar at all rates of applied nitrogen or timing of nitrogen application - due to the decline of oil% as nitrogen increased
• Hyola 404RR produced higher yields, oil and gross margins than CB Telfer TT - at all rates and timings of nitrogen application.

• Grain yield responded to applied nitrogen up to 70 kg/ha.
• Oil did not decrease as nitrogen rate increased, unlike what we have observed at other trials – probably a reflection of the continued grain yield response to N.
• Positive gross margin returns were seen at 40-70 kg/ha of applied nitrogen.
• Overall when nitrogen was applied did not alter the response to nitrogen – but avoid putting the majority of N at 12 weeks.

• Pioneer 43Y23 (RR) had higher grain yield, oil yield (kg/ha) and gross margins, than Sturt (TT).
• Grain yield responded to applied nitrogen up to ~ 40 kg N/ha.
• Both varieties responded similarly to applied nitrogen with no variety x N rate interaction for grain yield. 
• Oil yield and gross margins did not respond to applied nitrogen.
• Timing of nitrogen application did not alter the response to nitrogen of both varieties for GY, oil %, oil yield or gross margin.

• With grain yield of less than 1 t/ha, there was only a small grain yield response to applied N and no economic response to applied N.
• Top-up N at 12 weeks gave a similar response to top-up N at 8 weeks.

• With grain yield of less than 400kg/ha, there was no grain yield response to applied N and no economic response to applied N.
• At ‘low rainfall’ N rates of 30 kg/ha top-up N at 12 weeks gave a similar response to top-up N within 8 weeks.

• Pioneer 43Y23 (RR) perform better in terms of higher grain yield, oil yield and gross margins than Sturt TT, with both varieties producing similar oil %.
• Grain yield responded to applied nitrogen up to 30 kg N/ha.
• Maximum oil% was produced with no applied nitrogen.
•  Gross margins also responded to nitrogen application up to ~ 30 kg N/ha after which further increases in nitrogen led to no further financial gain.
• Overall when nitrogen was applied it did not alter the response to nitrogen of both varieties for GY, oil, oil yield and GM. 

•  In a dry year, there was no economic response to applied N.  

• Grain yield responded to applied nitrogen up to 30 kg N/ha.
• Highest oil %, oil yield and gross margins were obtained with no applied nitrogen.
• When nitrogen was applied, did not alter the yield, oil or $/ha response to nitrogen of both varieties.
• Thus 30, 50 or 70 kg N/ha applied either in splits at seeding and 8 weeks or seeding and 12 weeks provided similar responses.

The Cunderdin trial saw Pioneer 43Y23 (RR) perform better in terms of higher grain yield, oil yield and gross margins than Sturt TT, with both varieties producing similar oil %. Grain yield responded to applied nitrogen up to 30 kg N/ha.  As the rate of applied nitrogen increased the % oil in the seed of both canola varieties decreased at a rate of 0.02% oil per kg applied N/ha.  Gross margins also responded to nitrogen application up to ~ 30 kg N/ha after which further increases in nitrogen led to no further financial gain.  Overall when nitrogen was applied it did not alter the response to nitrogen of both varieties for GY, oil, oil yield and GM.   

For a full list of take home messages please see the attached trial report.

Please see attached trial report for take home messages.

• Soil applied fertiliser was and better than liquid urea or UAN applied with standard spray nozzles to the crops leaves.
• Both urea and UAN are equally as effective when applied to the soil.
• Growers should select the nitrogen product that most suits their farming system in terms of logistics and cost.

Large plot sites run by TOPCROP groups across the state generated many opportunities for discussing and fine tuning nitrogen management in canola. The season was the main factor influencing yields and gross margins. Nitrogen application of about 10-20 kg/ha for the Mallee and 10-50 kg/ha for the Wimmera gave best yields and gross margins at most sites in a difficult season.

• Fluid trace elements banded under the seed row is an effective system for delivering these nutrients to cereal crops.
• Rates of trace element application as banded fluids may be lower than for other seeding strategies and cheap sulphates can be used
• Mixes of trace elements as banded fluids are effective.
• Trial was not trace element deficient.

• No further yield benefit was measured from applying other nutrients (S, K, Mg) and trace elements (Zn, Mn, Cu) over and above that from applying nitrogen and phosphorus alone.

• Only 31 per cent of the applied urea nitrogen (N) was taken up by the wheat crop in 2014. This low fertiliser use efficiency may be partly related to the season; unused N in the soil can benefit the following crop.
• In a decile 1 season, different stubble retention practices had no effect on microbial biomass and N supply potential (avg. 58kg N/ha).
• Labelling a wheat crop with 15N allows researchers to quantify the fertiliser use efficiency and trace the N from stubble to the subsequent crop.

With pasture growing in a dry spring, not accessing stored water and producing little biomass, the effect on soil water/nitrogen and on the following crop is minimal. Prioritise paddocks which need medic seed set for retaining as pastures, but terminate more pastures later if feed is an issue. In a year when pasture is growing fast and using water and possibly fixing nitrogen, the trade-off may not be so flat (or simple) and will depend more on the following season (unpredictable).

• Normal traffic can easily reduce grain yield on this clay soil.
• This trial design is not very hard to use to quantify tramline farming systems.

• Wheat yields were significantly reduced by competition from barley and brome grass.
• The use of knockdown post sowing but pre-emergent provided excellent control of the grass weeds, which translated into a yield benefit.
• The trends in control of grass weeds and yield benefits in barley were similar to the results seen in wheat.

• We used Frame wheat in this trial, it could be that Flame is more tolerant to Triflualin than other wheat varieties.
• Do not use this technique before checking to see whether on your soil type and machinery the higher rates of Trifluralin are also safe to use.
• Do not use Trifluralin according to the techniques outlined if your soil is cloddy.

Differences in trifluralin tolerances exist between different wheat varieties, however the differences were not consistent. Over three years of trial work Silverstar was intolerant to trifluralin in one year (30% yield loss at Triflur480 2.4L/ha IBS in 1998) and tolerant in 1999 and 2000. In 2000 only Yitpi suffered a yield loss (20% yield loss at Triflur480 2.4L/ha IBS). There are no differences in tolerance when applying trifluralin immediately prior to sowing or post sowing pre-emergent as long as the trifluralin is not incorporated into the sowing band. Trifluralin residues in grain were below the Minimum Residue Level (less than 0.05ppm) for the plots with trifluralin used at the registered rate or at the high application rate (Triflur480 2.4L/ha). Trifluralin is registered at 0.8L/ha of Triflur480 applied at least 7 days prior to sowing. NuFarm have applied to the NRA for changes to the Triflur480 label - changes relate to higher rates for use in minimum tillage.

Frame is more tolerant to high rates of trifluralin compared to Goldmark and Silverstar.

• Triticale is very responsive to high inputs of seed and fertiliser.
• Adequate fertiliser is needed to achieve protein levels above 10%.
• In dry springs triticale yields are 10-15% below wheat, due to triticale’s longer grain filling period.

• Triticale requires 80kg of N to maximise yield.
• Triticale requires the same amount of nitrogen input as wheat to yield near its potential.
• Kocsiusko Triticale responds to the use of fungicide.

• Triticale responded to nitrogen (N) and fungicide in the last three years.
• In 2007, the response was to either N or fungicide
• The variety Toburk yields as well as Kocsiusko when not grazed.
• Tobruk did not respond significanly to fungicide.

• Triticale responded to nitrogen during 2008.
• Triticale did not respond significantly to fungicide during 2008.
• The variety Kosciusko yielded better than the variety Toburk.
• Kosciusko did not repond significantly to fungicide.

• Triticale tolerance of low manganese was much greater than for wheat or barley, but not as good as rye.
• Higher seen Mn in triticale varieties was correlated with greater yield.
• There was significant variation in manganese efficiency between triticale genotypes.

• The trial was designed to test the capacity of TwinN to enable reductions in nitrogen fertiliser applications.
• The control treatments showed no statistical difference in yield between 0 and 50 kg/ha urea but a difference was seen between 50 kg and 100 kg/ha ureas.
• Yield from TwinN plus 75 kg/ha urea was not statistically differenent from that from the 100 kg/ha urea.
• No treatment effects were found in protein% or screenings%.

Field observation suggests the 50% UAN solution produced a better stubble cutting action than water alone.

A network of soil moisture probes and Yield Prophet sites has been established across the Esperance, Albany, Kwinana East and Kwinana West port zones with the aim of providing public access to real-time soil moisture and weather data and periodic Yield Prophet reports to aid in-crop decision making, with particular reference to top-up nitrogen decisions.

Growers and agronomists have commented that the sites provided useful supporting information when making top-up nitrogen decisions, with the soil moisture probes providing additional confidence in the model’s output. Continuation of the Yield Prophet sites and soil moisture data recording and analysis will continue in 2015 across the Esperance/Albany and Kwinana East port zones, with the aim of further refining the sites to improve their accuracy and providing access to Yield Prophet and soil moisture information in a more user-friendly format.

• The 2015 season was cooler than 2014 which affected how canola varieties developed and grain yields.
• Early sowing presents a good opportunity to improve canola water use efficiency and yields but variety selection is important.

Spading alone and the addition of more clay did not appear to increase growth in this year. This would suggest that non-wetting and soil compaction were not major constraints affecting this site. The incorporation of organic matter combined with clay did, however, provide large increases to both dry matter and yield. The incorporation of organic matter provides a large nutrient benefit, particularly nitrogen, phosphorus and potassium. However, nutrients applied by the landholder should have been adequate to meet the yields delivered. Clay addition would have provided more than enough potassium.

• Vigorous growth in all crops and pasture treatments in 2009 has set up the trial for 2010, when the impact of soil mineral N on disease suppression will be assessed.
• At the start of the 2009 season there were already small differences in mineral nitrogen levels in the soil profile, spray topped medic having the highest with 63 kg N/ha and the control wheat the least with 44 kg N/ha.
• Since healthy medic will fix around 25 kg N/t DM, the medic spray topped treatment should have fixed around 125 kg N/ha during 2009.
• There were slight changes in Rhizoctonia inoculum in some treatments early this season but there were no visual differences in Rhizoctonia patches in the cereal plots in 2009.