• Test your soil- soil testing individual paddocks for nutrient status and plant available water at the start of the season allows you to determine the paddocks yield potential and requirements. Knowing this information at sowing can assist in making decisions throughout the season.
• Yield Prophet- the crop simulation model is a great tool for assessing crop risk and predicting potential yields.

The results to date from the systems trial are broadly summarized in the attached tral report.

• 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.

One way plough and Grizzly Offset discs appear to be the most efficient, practical most cost effective method of incorporating lime into the topsoil in the eastern wheatbelt wodjil soils.

• Substantially better brome control and seed set reduction is possible by using pre-emergence options other than trifluralin.
• The costly Sakura+Avadex treatment is likely to be the most effective.
• Consistency of performance of all pre-emergence herbicides for brome remains a problem
• On-row seeding on non-wetting sand showed that it can substantially improve early crop emergence.
• One reason for this is the likely wetter surface soil in rows at time of seeding.
• Seasonal conditions such as the long-wet season of 2016 will affect efficacy of both pre-emergence herbicides and the impact of additional crop competition on brome seed set suppression.
• Maintaining low seedbanks and having alternative options for weed seed control when faced with a risk of ‘blowouts’ in brome seed set is important given the chance of particularly poor control in some seasons.

• Substantially better brome control and seed set reduction is possible with pre-emergence options other than trifluralin.
• The costly Sakura+Avadex treatment is likely to be the most effective.
• Consistency of performance of all pre-emergence herbicides for brome remains a problem
• On-row seeding on non-wetting sand can substantially improve early crop emergence in part due to increased surface soil water accumulation in rows at time of seeding.
• Seasonal conditions such as the long wet season of 2016 will affect efficacy of both pre-emergence herbicides and the impact of additional crop competition on brome seed set suppression.
• Maintaining low seedbanks and having alternative options for weed seed control when faced with a risk of ‘blowouts’ in brome seed set is important given the chance of particularly poor control in some seasons.

• The later seeding had very poor crop establishment, resulting in significantly higher brome seed production (115% more panicles) than early seeding, but seeding time did not interact with herbicide treatment effects.
• Only the treatments including Sakura resulted in significantly (P<0.01) better brome control than trifluralin alone (measured by number of panicles/m2).
• Sakura alone resulted in 55% less brome panicles than trifluralin alone, and Sakura + Avadex resulted in 72% less brome panicles than trifluralin alone.
• Sakura’s extended residual soil activity, which can restrict root growth of brome, combined with the dry spring, was probably responsible for the reduced seed set.
• Substantially better brome control and seedset reduction is possible by using pre-emergence options other than trifluralin. The additional herbicide cost needs to be evaluated against the better level of control, including the longer-term seedbank benefits.

Changes in pasture composition, groundcover, stocking rate and stock condition are being monitored at each grazing site. Soil moisture is being measured at one pasture site (to 1.2m) and one cropping site (to 1.6m). Water quality will be monitored at one pasture site opportunistically depending on flow. Photo points were established and soil pH and nutrient testing was undertaken at all sites.

• Canola and peas only produced half the yield of wheat, but barley performed very well.
• Ryegrass is becoming a problem in wheat on wheat plots.
• Pastures performed well where seed reserves had been increased in 2011.
• All options had good soil moisture (40mm) at the start of the season.

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.

Soil organic matter consists of a labile (non-permanent) and stable (humus) fraction. No-till increases the labile fraction of soil organic matter, but not the stable fraction. Additional nutrients will be required to ‘fix’ the labile fraction to humus.

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.

• Quality of on-farm lime and distance from coastal limesand sources are important factors in determining economic advantage over coastal limesand
• Cultivation of sources resulted in higher net present values after the 20 year iLime simulation, and improved return on investments at 5 and 10 years compared to when uncultivated
• In 2019 cultivation consistently improved yield and the high rates of local dolerite and limesand improved yield by 0.55t/ha and 0.57t/ha respectively.
• Due to the 2020 season and in season challenges there were no significant differences in yield between sources and cultivation

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.

• A replicated trial was conducted to compare grain yield of early sown Revenue wheat (cut and uncut for fodder) with that sown at a more traditional time, May.
• Both cutting and later sowing significantly reduced grain yield compared with the early sown uncut treatment.
• The most significant effect was the ability of the early sown plots to better tolerate the very wet conditions. With a root system actively depleting moisture from the soil profile in late autumn the early sown treatments entered winter with a depleted soil moisture bank whereas May sown plots struggled over winter due to additional water logging.
• March sown plots that were cut did not recover as well as in drier seasons. It is likely that the prolonged water-loggin created an addional stress on top of cutting to the detriment of crop recovery and grain yield.

• Despite visual differences there is no major impact on soil structure, water holding capacity or water infiltration from grazing in summer or winter when soils are water logged.
• Grazing in the previous winter or summer does not affect the following crop establishment or grain yield.
• Any yield losses after winter grazing are the result of moisture stress in the period immediately after grazing through to flowering.
• Annual ryegrass and wild raddish populations did not increase because of grazing, although the sites only had low levels of infestation to being with. However, farmer observations do not support this and further work is needed.

• Despite visual differences there is no major impact on soil structure, water holding capacity or water infiltration from grazing in summer or winter when soils are waterlogged.
• Grazing in the previous winter or summer does not affect the following crop establishment or grain yield.
• Any yield losses after winter grazing are the result of moisture stress in the period immediately after grazing through to flowering.
• Annual ryegrass and wild raddish populations did not increase because of grazing, although the sites only had low levels of infestation to begin with. However farmer observations do not support this and further work is required.

• 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.
   

• Higher seed manganese content increase growth and yield of barley on manganese deficient soil.

The high rate of gypsum (3.0 t/ha) was the best ameliorant, with all other ameliorants and rates performing better than the control (no ameliorant).

• 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.

• Sowing canola early (6 April) on 200 mm applied water reduced the time to the start of flowering by up to two weeks, compared with a later sowing (7 May).
• Significant yield increases were recorded across all varieties (for both sowing dates) where 200 mm water was applied pre-sowing, compared with 70 mm and 0 mm.
• The highest yield resulted from sowing a mid season hybrid (Pioneer® 45Y91 (CL)) early on 200 mm applied water.
• Sowing canola early on 200 mm applied water yielded around 900 kg/ha more than sowing later with the same amount of applied water, averaged across all varieties.

• Each stubble incorporation prior to sowing lead to better weed control in the crop as we were able to create an early germination of ryegrass. 
• There was considerable difference in soil moisture and its distribution through the profile at establishement.
• Straw length at harvest was the biggest drawback in incorporating and establishment.
• Previous trial cropping areas, on other parts of the padock, still showed up the biggest difference in the crop's establishment.

• Soil inversion with a mouldboard plough, rotary spader and one way plough created equally patchy soil.
• The one-way plough created the most vertical redistribution of the surface 10 cm of soil.
• At least ten soil samples are required to gain a reliable mean for soil pH after inversion.

• Grain and soil samples were collected from 13 field experiments where zinc deficiency had been identified as a problem.
• Zinc was applied in the field experiments at rates of 0-20 kg zinc/ha.
• Application of zinc (2.5 - 5 kg/ha) reduced grain cadmium concentraitons by up to half.

• Most of the endogenous zinc in the soil was associated with silicates while zinc added as fertiliser was associated with iron, aluminium and manganese oxides.
• Zinc recently added to soil in the EDTA extractable fraction decreased over time.
• Zinc recently added to soils was found to be mor reactive than zinc already in the soil.
• The transformaiton of reactive zinc to less reactive zinc was primrily attributed to diffucion of zinc cations into microporous solids.
• Dryindg and rewetting at high temperature may reduce the availability of zinc in soils.

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.

• 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.
   

• Grain yields increase with higher crop inputs and, after grazing, further improve following a sown legume pasture and a more intensive grazing system.
• There is no measured change in soil organic carbon as a result of either varying crop and pasture inputs or grazing compared with not grazing stubbles or pastures.

• Grain yields increased with higher crop inputs and following grazing, they were further improved following a sown legume pasture and a more intensive grazing system.
• There has been no measured change in soil organic carbon over the 4 year project as a result of varying crop and pasture inputs or grazing compared to not grazing crop stubbles or pastures.

• 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).

• The 2009 production has provided the opportunity for grazing over the 2009/10 summer to commence comparative grazing treatments.
• Over the next few seasons appropriate analysis will be carried out to measure any changes to soil or crop performance in the farming systems, followed by financial assessment to evaluate the merits of each system.

• 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.

• Although time of heading and flowering are considered the most sensitive stages for frost damage in cereals, sensitivity to early frost damage occurs from the start of stem elongation and is referred to as ‘stem frost’.

• Stem frost can be minimised by matching sowing date and cultivar phenology so that stem elongation starts after the period of greatest frost risk.

• Varieties that started stem elongation early (fast developing varieties sown early) were exposed to an increased number of frosts during the susceptible development stages, whilst winter types sown early had an extended vegetative period and were not exposed to the same frost risk, which reduced damage from stem frost.

• Crops can recover from stem frost where there is moisture available to support new tiller growth. However, the resulting effect on phasic development stage synchrony leads to delayed maturity and harvest issues.

• There was no observed difference in frost tolerance of specific cereal species observed in 2017.

In 2019, the three trial sites experienced vastly different rainfall and crop germination patterns. The Kojonup site had good soil moisture throughout the growing season resulting in a rapid crop germination. The York and Miling sites however were seeded into completely dry conditions with the wheat germination in the TOS 1 treatments occurring more than six weeks after seeding. The bioassay experiment showed that at all sites, Sakura was the most persistent herbicide. This was evident in the field results where the persistence and activity of Sakura resulted in lower ryegrass emergence, lower seed production and a higher wheat yield. Furthermore, the results showed that at the Kojonup site, which was sown into excellent soil moisture, Trifluralin was also very effective.

The TOS response was variable; the first time of seeding showed better weed control and wheat yields at Miling and York whereas the delayed time of seeding was advisable at the moist Kojonup site. It was also found that increasing the wheat density increased crop competition which in turn reduced ryegrass emergence, ryegrass biomass and ryegrass seed production for all herbicide treatments studied. 

• 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.

• Widespread manganese toxicity a function of soil acidity.
•  A few reports of manganese deficiency in rapeseed, field pea, sunflower and soybean in NSW.

Phosphorus was applied as Triple Super drilled with seed. The result was lower plant densities as phosphorus rates increased.

For an interpretation of results please see the attached trial report.

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.

 

• Significant responses in lucerne seed yield were achieved with foliar manganese applications on 2/5 irrigated lucerne sites at Keith.
• Plant tissue analysis prior to the application of manganese show the concentrations at both responsive sites were less than 14 mg per kilogram in the youngest open leaf and whole shoots.
• this contrasted with concentrations from 3 other sites we seeded did not respond to manganese, the mean concentration being greater than 18 mg per kilogram in youngest open leaves and 14 mg per kilogram manganese and whole shoots prior to treatment.

• Stubble rentention increased the severity of frost events in experiments over two years
• There was no difference in floret sterility due to stubble treatment, but grain yield was highest where stubble was removed by burning. 
• Stubble rentention reduced the amount of heat stored in the soil during spring. With less heat stored there is less capacity for energy release at night to buffer against frost damage.
• Consider management strategies that avoid frost (e.g. crop choice, sowing date, variety choice) where high stubble loads are retained at sowing. 

The application of compost at 2 t/ha did not result in higher returns and the response under compost plus fertiliser treatments could be attributed to the application of fertiliser. Spading did not return any further gains in terms of yield or quality at this site in 2013. The high cost of spading and compost in the first year, have negatively influenced profit outcomes. Depending on future yield improvements, these treatments may pay for themselves over the longer term.

No measureable changes in soil condition as a result of adding 2 t/ha compost were measured in 2013 and 2014 that would add value to the long term profit of this site.

Machinery used for applying compost caused some compaction and due to the dry post-sowing conditions, crop germination was very patchy. The trial site experienced significant moisture stress early in the season and may not be representative of seasons experiencing an average or wetter start.

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.

• 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.

• The value of stored soil moisture at seeding in the Northern Agricultural Region of WA is not well understood.
• In trials so far, value of stored soil moisture at seeding has varied depending on season and soil type.
• In 2013, additional water at seeding increased yield by about 500 kg/ha at the sand site, and by 1000-2000 t/ha at the loam site.
• Trials such as these will help to unravel the value of stored soil moisture so that it can better be used as a predictor of crop performance and nutritional requirements.
• Available water at sowing is a poor predictor of expected yield and cannot be used as a simple tool for adjusting input levels. We need to develop an ability to understand when and why the water will be of benefit. 

High machinery loads and working when soil moisture is not optimal can cause topsoil and subsoil compaction.

• There was no significant pH changes within the first year of the demonstration however there was a trend for an increase in subsoil pH of 0.2-0.3 pH units following deep banding of lime.
• Predicted some of the lime deep banded in 2001 would remain undissolved and further pH increases should take place subsequently.
• Despite not significantly changing soil pH, there were first year yield responses in wheat following ripping, and the injection of lime.
• From a perspective to have lime react, it would seem imperative to have a deep tillage operation every few years.  Once a certain portion of lime has reacted, the residual lime then sits in a highly alkaline (caused by the dissolution of some of the lime applied) zone, within a highly acidic soil.  The chance of the excess lime present deep in the soil profile coming into contact with acid soil, to subsequently react and change more of the overall soil pH appears to be reliant upon some degree of mechanical intervention.

• A unique trial design (double up of each plot) was designed to allow destructive biomass sampling, and grain yield measurement
• This trial site was primarily used in a ‘screening function’- to evaluate any negative impact of lime of a variety of different legumes which was considered to be happening during the mid 1990’s. The key concern was to investigate if manganese deficiency was induced by liming
• The trial was sown to lupins in 1994, wheat in 1995.  Data not available
• Yield responses (negative) were apparently not noted in the early years following establishment of the trial.  Positive yield response did occur, several years post trial establishment
• The double up design allowed comparison of lime sources on many different species.  For example, in 1996, narrow leaf and yellow lupins were compared.  No data available
• In 1997 the trial was sown to wheat, no yield responses reported
• In 1998, the trial was sown to a diverse mix of new pasture legumes that were at various stages of evaluation prior to commercial release.  Some of the material screened, that subsequently was commercialised included Cadiz French serradella, Santorini and Charano yellow serradella, Casbah Biserrula, Prima gland clover and finally Bartolo bladder clover.  The primary focus of this work was to assess any negative impacts of lime on legumes.  No negative impacts reported.
• The inclusion of this trial into this sampling regime, was primarily because of the known (high rates) of lime subsequently applied by the cooperating farmer, and the focus to see if these high rates had changed soil pH deeper in the profile, which did not occur initially.

• 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

• During the first few years of this trial being monitored, there were significant changes in soil pH due to the application of lime, and these changes resulted in significant grain response

• The ‘top up’ application (1.5t/ha, across all initial lime rates of 0, 1 and 2t/ha)) of lime applied in 2006 (10 years post trial establishment) has had dramatic impact on current soil pH.  Unfortunately, grain yields have not been monitored post the top up lime application.

• The 2016 pH measurements provide clear evidence inadequate lime has been applied to counter inherent and ongoing soil acidification. From a starting surface pH of 4.8 over a subsurface of 4.6 (in 1996), the highest rate of lime applied has been 2t (1996) and a further 1.5t (2006) is simply insufficient to lift soil pH above the DAFWA stated targets (5.5 over 4.8).

• Despite soil pH being under target, this trial provides a clear demonstration of the best soil pH profile being associated with the highest rate of lime application.  Collecting grain yields would be valuable

•    During the early years following trial establishment, there was no grain yield response measured
•    In 2004/2005, some 8 years post initial lime treatment, strong visual responses to lime became apparent
•    The ‘top up’ application (1.5t/ha, across all initial lime rates of 0, 1 and 2t/ha)) of lime applied in 2005 (9 years post trial establishment) has had dramatic impact on current soil pH, and the soil pH profiles now reflect lime applied
•    Only the highest rate of lime treatment (initial 2t/ha) followed by the 1.5t/ha in 2005 have a soil pH profile above the DAFWA recommendations (5.5 in the surface, over 4.8 at depth)
 

• 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.

Cu fertiliser greatly increased yield from 0.6 t/ha to 1.60 t/ha.  

In general oxide source was equal to or superior to the sulfate source in wet mixes. In dry mixes in the same trial Cu oxide was only 66 % as effective as the sulfate.

A recent development in diagnosing Cu problems by a technique of using the youngest fully emerged leaf. Copper concentrations of less than 1.3 ppm (mg/kg) in the yougest fully emerged tissue , suggest that soil Cu deficiency will reduce grain yield .

The tissue testing technique was used on arange of Cu trila in the district to confirm the method (UWA Lonragan, Robson , Snowball)

For the first time it has been possible to distinguish crop damage caused by Cu deficiency from that caused by other factors such as frost, drought and root rots which produce similar symptoms.

Cu fertiliser greatly increased yield from 0.6 t/ha to 1.60 t/ha.  

In general oxide source was equal to or superior to the sulfate source in wet mixes. In dry mixes in the same trial Cu oxide was only 66 % as effective as the sulfate.

A recent development in diagnosing Cu problems by a technique of using the youngest fully emerged leaf. Copper concentrations of less than 1.3 ppm (mg/kg) in the yougest fully emerged tissue , suggest that soil Cu deficiency will reduce grain yield .

The tissue testing technique was used on arange of Cu trila in the district to confirm the method (UWA Lonragan, Robson , Snowball)

For the first time it has been possible to distinguish crop damage caused by Cu deficiency from that caused by other factors such as frost, drought and root rots which produce similar symptoms.

• 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.

• This trial showed that timing of N application is critical to yield potential, this showed that early foliar N had greater significance than application of other nutrients like potassium and trace elements.
• The trial also showed that seed treatments can develop significantly greater root biomass than unapplied seed.

• One hundred barley lines from a world collection were grown in plant breeders' plots (4 rows x 5 m) on a severely manganese-deficient soil.
• Only 10% of the lines showed good tolerance of manganese-deficient conditions, which were severe enough to kill many of the entries in the tillering stage.
• Extreme sensitivity to manganese deficiency was shown by all progeny of CI3576, an introduction from Egypt, which has conferred considerable yield advantage and disease resistance on its progeny under more highly fertile conditions.
• In all, there were 20 lines from CI3576, including Corvette, and Galleon, a newly released high-yielding feed barley.
• At present, Galleon is not recommended for calcareous sands, pending further agronomic work on its manganese fertilizer requirements.
• The established variety Clipper and its relatives, and Forrest, were also sensitive to manganese deficiency. The tolerant lines fell into three genetically related groups, all of which had pedigrees going back to traditional English land races or their derivatives.

• Wheat, barley, triticale, canary seed, sorghum, sunflowers, millet and panicum were grown in a copper deficient clay soil in pots in the glasshouse.
• For rates of copper from 0 to 6 mg per pot for winter crops, and the same plus 60 mg per pot applied to the summer crops.
• A rate of 6 mg per pot was not sufficient to maximise yield from the winter crops but some are crops produced maximum yields when 60 mg per pot was applied.
• Significant differences intolerance to copper deficiency were apparent between varieties within crops.
• Only the summer crops in triticale produce grain when nearly all the lowest rates of copper were applied.

• A series of glasshouse experiments were conducted with a range of different soils planted to triticale, wheat or rye.
• In one experiment at pH 5 and pH 8.4, triticale was tolerant of flow copper at pH 5 like rye but sensitive to low copper at pH 8.4 like wheat.
• Copper concentration in shoots decreased as pH increased the effect was greatest in wheat and lowest in rye.
• In a similar experiment with zinc these relativities were maintained, that is rye was most tolerant of zinc deficiency and wheat least tolerant.
• In a third experiment in soils deficient in both copper and zinc, these relationships were maintained but adding zinc alone aggravated copper deficiency and decreased pollen viability and yield, while adding copper alone generally increased pollen viability and yield.

• In 2017 no consistent differences in wheat yield were observed among plots established with different sowing implements.

Tor top dressing to be effective on canola the following points are required:

• It needs to be applied to a crop with marginal soil N levels that has the potential to respond.It must be applied before the crop suffers an unreasonable yield potential loss due to N deficiency.
• This will usually mean top dressing before stem elongation.
• The crop also needs good growth conditions after top dressing so that it has potential to provide an economic response.

• Deep placed trace elements can be more effective than the same amount placed just below the seed.
• Foliar application of trace elements was just as effective as deep placement at increasing crop yields.
• Deep placement increased grain uptake of all nutrients compared to other methods of trace element application.

• Copper, iron, manganese, molybdenum, and zinc were analysed in 45 soil samples from the lower south-east of South Australia, an area well-known for trace element deficiencies
• Absolute levels of all trace elements except molybdenum were very low for most soils of this region compared to average values for other parts of the world
• For soils similar in respect to profile features, parent materials and drainage conditions, each trace element maintains some consistency in its total content in the soil.
• This was shown particularly in relation to the terra rossas and rendzinas.
• Terra rosses on dune limestone is distinguished by higher manganese and molybdenum from the groundwater rendzinas on marls, which have higher cobalt, copper, zinc and iron.
• Several trace elements, especially cobalt, copper and zinc, are significantly higher on the small area of soils developed on volcanic rocks.

• Laboratory analysis of 14 red brown earth soil profiles from South Australia.
• Molybdenum, copper and cobalt concentrations were all strongly correlated with clay content but manganese was not.
• Manganese concentration was correlated with the silt content.
• The relative mobility of the elements in soil was directly related to their position in the periodic table (excepting for cobalt) Co>Cu>Mo>Mn.
• Molybdenum concentration should change with surface clay content but not that for copper and cobalt.

• The concentrations of cobalt, zirconium, nickel, copper, vanadium, molybdenum, and manganese were determined in soils.
• The soils from the lower South East of the state contain lower concentrations of all of these elements than do those near Adelaide, particularly for cobalt, copper and zinc.
• This difference is reflected in the concentrations of calcareous material in the soil.

• Copper deficiencies have been reported but are usually corrected with fertiliser addition, however diagnosis can be a problem.
• Some evidence for boron deficiency on sandy dune soils in the Murray Mallee, upper south east and Eyre Peninsula, only a narrow range in soil B between deficient and toxic. Alkaline calcareous soils are known to contain toxic concentrations of boron.
• Molybdenum deficiency occurs on acid soils in the Mt Lofty Ranges, Fleurieau Peninsula, Clare Hills, Kangaroo Island, south-east and lower Eyre Peninsula. It has been recorded for legumes but not cereals.

• 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.

• Over the last four years, trafficking at any level has not decreased crop production on a heavy Minnipa soil so moving to controlled traffic farming on this soil type is not likely to increase crop production due to less trafficking in the paddock.
• Trafficking on a deep sand (trial at Loxton in the northern mallee) has substantially reduced crop production for at least 4 years so CTF may have additional benefits on deep sands, especially if ripping is used to correct existing compaction.
• Similar to many previous trials, ripping has not benefited production on the heavy Minnipa soil.

• Tonic plantain and Grouse chicory are worth considering as summer forages, with the Tonic plantain likely to persist through the following winter and longer. Although not tried, Italian ryegrass (or perennial ryegrass) could be oversown for more winter feed. In this trial, winter feed production from Tonic plantain and sub clover was excellent, no doubt partially due to the high sub clover seed reserves and partially due to the high soil fertility on Tremaine’s.
• Banquet tetraploid hybrid perennial ryegrass could be considered for a medium term high quality pasture for finishing lambs/weaners in high fertility paddocks, with controlled rotational grazing over summer.

• 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.

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.

• Ornithopus sativus (French serradella) and O. compressus (yellow serradella) had a significantly high root hair cylinder volume compared with Trifolium subterraneum, which provides for a great phosphorus (P) foraging ability and helps explain why the Ornithopus species has lower critical P requirements than T. subterraneum.

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.

Growers and their advisers in the area are more familiar with soil water relations, N dynamics and variation of yield potential in relation to soil types and season. Their integration into Yield Prophet reports has been demonstrated. This should lead to some commercial adoption of Yield Prophet and other crop decision support systems for better management of crops leading to increased profitability through management of seasonal risk.

Inversion ploughing of water repellent sands can significantly reduce repellence and increase critical components of grain yield.

Deep ripping in the presence of problem background ryegrass can stimulate ryegrass emergence and worsen weed competition with the crop.

The strength of the subsoil resource (i.e. clay component) appears important in sustaining the crop production potential and realisation of grain yield improvement.

• In the fourth trial season lentil grain yield benefits were observed from spading and lime treatments. Addition of lime (2200 kg/ha or 6600 kg/ha) and mixing with low, medium or high uniformity were the highest yielding treatments ranging from 3.36 to 3.69 t/ha.
• Lime rate and spading have had variable response on NDVI across four years. 
• In the first three years of the trial plant establishment has generally not been affected by lime rate, spading uniformity or deep ripping.
• Lentil tissue tests in year four revealed increased Mo levels (>0.3 mg/kg) in treatments where lime was applied.
• Soil samples taken in 2022 showed both the high and low uniformity treatments plus lime have increased soil pH compared to the control. The high uniformity has had the greatest impact on soil pH across the 5 to 30 cm sampling depths. 

• 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.

• Removing subsoil compaction is critical and for some soil types can dramatically improve access to deep soil moisture.
• Correctly ground-truthing the depth of the compaction layer can drive the success or failure of ripping outcomes.
• Yield increases at the Goomalling site were largely driven by very deep ripping, with either the very deep ripper or delver, with yield increases of 0.55-0.74 t/ha, an increase of 74-93%. The only other treatment to increase yield was mouldboard ploughing on its own with a 0.44 t/ha, 55% yield increase.

At three field sites in WA, increased wheat yield was achieved at lower nitrogen (N) application rates when N was balanced with appropriate phosphorous (P), potassium (K) and sulphur (S) applications. Wheat yield was driven by the ratio of N to P and K rather than the absolute concentrations of the nutrients and it is possible to increase profit margins by balancing nutrient inputs.

The level of background nutrients present in the soil at sowing was a key factor in determining the responsiveness of yield to fertiliser applications and how profitable the fertiliser treatments were. Pre-season soil testing to determine the level of residual nutrients will allow growers to balance their nutrient inputs and help to maximise profits.

• 14 vertisols were sampled and analysed in the laboratory, and were sown to wheat in the glasshouse.
• DTPA-extractable zinc, zinc desorption and diffusion rates, and buffer power were measured.
• DTPA-extractable zinc and zinc desorption rate accounted for 80% of the variation in relative dry matter yield of wheat at anthesis.
• Inclusion of buffer power increased this to 92% of the variance in relative dry matter yield.
• These measure provide a better indicaiotn of the likely responsiveness of soils than the traditional single DTPA-extractable zinc.

With a soil nitrogen content of 153kg N/ha at sowing, Derrimut wheat yielded just less than 6 t/ha with no N fertiliser.

• Crop sensors are a useful tool for measuring and mapping the growth of crops, however their limitations need to be recognised.
• Poorer crop growth and lower sensor NDVI values can indicate lower N availability within a paddock, but this should be ground truthed, rather than assumed as there are many potential constraints to crop growth that could also be the cause.
• The use of an N-rich strip in conjunction with crop sensors can provide an indication of the likely grain yield response to N.
• The N rate calculation still requires a yield prediction – a potential fit with APSIM / Yield Prophet.
• Utilising predefined paddock zones created from historical yield and/or soil data may help to refine the use of crop sensors for variable rate applications.

The objective of this GRDC / SPAA funded project is to increase the level of adoption of PA 'beyond guidance' by broadacre farmers. The project specifically aims to increase the level of adoption of variable rate (VR) by growers in the project to 30% by 2013.This goal will be achieved by demonstrating how to use PA tools to growers at a regional level and by increasing the skills of growers and industry in PA to a level where they can then use PA tools in their farming systems to achieve economic, environmental and social benefits.

A yield increase is apparent in figures 2 (circled) and 3 (see attached Trial report) at the ripped only treatment in the eastern plot, however this is not seen in the western plots and does not stand out in graph 1. Results presented in Graph 1 generally show only slight differences with the greatest response observed in the gypsum only treatment on the eastern plots. This soil was highly sodic at 10cm and as could be expected the gypsum would make a quicker impact on sodicity, thus allowing for improved drainage that may have improved crop production. Gypsum would take longer to impact on subsoil sodicity and may show a response after several years of data are collected

Yield stability and Adopting VRT.
In the initial phase of the project, trial paddocks were selected that had a high degree of
variability. The aim was to exploit this variability to increase whole paddock profitability.
As we learnt more about crop performance in individual paddocks, it became apparent
that some paddocks had a high degree of variability from season to season as well as
between zones (i.e. a high performing zone one season could be a low performing zone
the next). This makes using variable rate technology (VRT) to achieve target yields is
very difficult.
We have developed some rules of thumb for determining if VRT is likely to be profitable
based on the percentage of the paddock that is stable through time.
Highly suited to VRT = >70% Stable
May suite VRT = 55-70% Stable
Unlikely to suit VRT = <55% Stable
Our research shows that unstable zones within a paddock are usually impeded by soil
physical or chemical constraints such as water logging, sub soil acidity, sub soil
compaction. Water logged sites tend to be low yielding in wet seasons and high yielding
in dry years. Sites with subsoil problems tend to perform like medium zones in seasons
with a soft finish and like low zones when there is a dry end to the season.
Trial results have given economic responses (up to 500kg/ha) in the first season to deep
ripping to overcome a tight subsoil.
Most trial sites have not given economic yield responses to additional applications of
nitrogen, phosphate (and potassium on some sites). To date the most profitable treatment
has been the low fertiliser input strategy in high or low yielding seasons.
7
Water Storage Determines Yield
University of Western Australia honors student Josh Whitwell joined the project to assess
how water holding capacity of soil affects yield in that zone. Josh found that grain yield
was determined mainly by a soil’s ability to store and supply water to plants. The high
productive zones commonly had soil profiles that could store larger amounts of water and
supply it back to the crop. Of the 45 sites investigated, 40 were found to have limited
rooting depth due to critical amounts of pH, EC and soil strength. This suggests there is
scope to increase grain yield by ameliorating subsoils.
Focus for 2006 and 2007
With the project extension now approved we intend to focus on continuing research on
the main trial sites to increase replication through time. We hope with the additional two
trial years we can better understand how seasonal conditions interact with zone
management.
We also intend to compare the different paddock zoning methods used by our
collaborating partners, Gamma radiometrics, (B Whelan, Sydney University) and Crop
biomass image analysis (I Mailing, Silver Fox) with zoning from actual yield data.
Economic Analysis
Over the three trial years we have seen a large fluctuation in fertiliser cost and grain
prices.
For all economic calculations the prices have been standardized to eliminate year to year
fluctuations in grain price or fertiliser cost. This has enabled comparisons through time.
• Wheat price – A net in bank wheat price of $180/t plus or minus AWB golden
rewards quality bonification (July 2005). The $180 net in bank price reflects the 5
year average for wheat delivered Corrigin.
• Malt and Feed Barley price – A net in bank wheat price of $198/t (malt) and $153/t
(feed) plus or minus quality bonification. The net in bank price reflects the 5 year
average for barley delivered Corrigin.
• Lupin price - $190 net in Bank.
• Canola price - $355/t net in Bank plus and minus oil bonification as per grain pool
July 2005. This reflects the 5 year average net in bank canola price for Corrigin.
• Fertiliser prices – 2004 Company list prices were used for all 3 trial years.