• Native grasses have been established on numerous properties, however the project has highlighted difficulties with sowing light fluffy seeds.
• Wallaby Grass established well at several sites, however the dry summers have drastically reduced populations.
• The dry springs have not been suitable for the establishment of Windmill Grass and rain in the middle of summer does not appear to favour establishment

• In general for the bulk of the paddock in the wetter 2011 season there was little obvious difference in establishment between the knife point and winged point with paired rows seeder. However there were a several water repellent patches where establishment was poor for the knife point seeder but was much improved for the winged point-paired row seeder.
• Plant counts in these areas revealed that establishment was more than doubled from <100 plants/m2 to >200 plants/m2 through use of the winged point-paired row system in both the sandy gravel and pale deep sand soil types
• The advantage of improved furrow sowing as a tool to manage water repellent soils is it can be applied over all the repellent cropping areas, potentially for relatively low cost if only points and press wheels need changing on an existing seeder.
• For further results please see the attached trial report.

Yield variability across the 22 focus paddocks in the project was moderate to very high. Yield variation needs to be managed to minimise the significant economic losses experienced in low performing parts of a paddock. We found very good correlations between soil EM38 maps, satellite imagery of crop vigour and crop yield at harvest. Utilising our knowledge of how the crops grew this season together with the precision farming tools available we will develop management plans in each of the focus paddocks to improve water use, yield and economic return.

• Profitability and risk are driven largely by a combination of soil type, associated enterprise mix, level of debt, machinery investment and land purchases.
• There is not best best farming system. Successful farming depends on factors within each system such as labour, soil type, rainfall and skills.

• No measured improvement in phosphorus uptake through low seed bed utilisation systems.

• The paddock utilised for the trial had a significant number of effective naturalised medic rhizobia. There was no rhizobial inoculation response.
• Total annual biomass was higher in the regenerating medic plots versus sown treatments due to earlier germination and growth of naturalised medic.
• Grazing increased overall medic production.

• The paddock contained a population of effective rhizobia and so the number of nodules on lateral and taproots was not affected by the addition of different rhizobial inoculants.
• Improved soil nutrition did not affect dry matter production and nodulation.
• Grazing (simulated) reduced the total dry matter produced by the medic pasture, however the use of sheep would provide a more realistic assessment of grazing on DM production, nodulation and N2-fixation.

While water volume and droplet size were the focus of this study there are further measures that can be taken by the spray operator to increase herbicide penetration in stubble. In a recent paper by Gordon (2017) some of the strategies highlighted were:

• Reducing spraying travel speeds can generally improve the penetration into stubble and improve the evenness of the application.
• Narrower nozzle spacings can also be of benefit, provided the spray quality and boom height are suitable. 
• Alternately, many operators have plumbed machines with nozzle spacings to match the crop row width. Where nozzles are positioned in the centre of the inter-row gap between standing stubble lines, the nozzle height may be lowered to obtain an overlap close to the base of the stubble. This may improve soil contact and reduce interception by the stubble, provided spraying speeds and wind speeds do not excessive.

(i) Baits do kill juvenile snails. (ii) Stubble and/or green plant material reduce uptake of snail bait by juvenile snails. (iii) A baiting program that is integrated with appropriate stubble and weed management at presowing is likely to optimise snail control. (iii) Calibrate your bait spreader to optimise the effectiveness of your baiting program. (iv) Perlka® did not have a significant effect on reducing snail populations in caged field trials. (v) The effectiveness of bait product and bait size differs between the pest snail species; once fully researched,future bait program recommendations will be tailored to the species being targeted.

• Most legumes favour pHCa > 5.0 to a depth of at least 20 cm; acidic layers below 5 cm adversely affect root growth, nodulation, plant vigour and N2 fixation potential of acid-sensitive pulses.
• Ineffective incorporation of lime under minimum tillage systems confines the lime effect to the shallow surface layers (0-5 cm).
• An ‘acid throttle’ located between 5 to 20 cm in the soil profile is not detected using soil samples collected at standard depths of 0-10 cm and 10-20 cm, finer sampling at 5 cm intervals is recommended to detect acidic layers.
• Apply and incorporate adequate rates of fine grade, high quality lime at least 12 months before sowing acid-sensitive species to allow time for the lime to react and increase pH to the depth of incorporation.

• There was no effect of stubble retention on canola yield because it followed chickpea and there was very little, if any, stubble of chickpea.
• There was no significant effect of gypsum application on the yield of both canola and chickpea.

• Pasture legumes are suited to crop rotations, even short 1:1 rotations.
• Pasture legumes can improve the grain yield and protein content of subsequent crops.
• Pasture legumes appear to provide an advantage to the subsequent crops not provided by fertiliser N (50 kg/ha).
• Pasture legumes regenerate well in the year following a crop.
• Reasonable yields can be obtained from spring sowing of wheat. 
   

• The pasture-crop rotation system has so far been successfully established in these sites, with the pasture plant productivity improved year by year.
• For further discussion and conclusions from this work please see the attached trial report.

Climate variability or climate change? Whatever the situation we face we need to be prepared to respond quickly to temperature and rainfall extremes with better in-crop management decisions.

• Electromagnetic (EM) zoning was strongly related to differences in pH at 10–30cm depth in two out of three paddocks.
• All three paddocks showed variability in chemical properties, with the EM zoning showing good separation of chemical properties between zones. This provides confidence that the zoning was suitable.
• Variability in plant growth needs to be examined ‘holistically’ rather than just focussing on one variable. While a paddock may show variation in plant available water (PAW), it may be that sodicity or subsoil acidity is the key limiter in plant performance, not water availability per se.
• Existing precision agriculture (PA) datasets, in conjunction with selected chemistry sampling, can be used to indicate relative change in PAW across paddocks, but not the actual volume of water storage.

RESEARCH QUESTION

Can incorporation of lime economically remediate a subsoil acidity constraint on gravel soils?

RESEARCH OBJECTIVES

• To evaluate four rates of lime
• To compare three methods of incorporating lime
• To investigate an optimal combination of application rate and method of incorporation for ameliorating soil acidity

 

BACKGROUND SUMMARY

Forest gravel soils are common in the medium to high rainfall zone of Southern Western Australia and are estimated to account for about 2.4 million hectares of the state's farming area.  Non-wetting and soil acidity issues are known to constrain the productivity of these soil types, which are common throughout the Southern DIRT region. Considering this, limited local research has been conducted in regards to the effects of incorporating lime as a method to alleviate these soil constraints more effectively and economically than the traditional method of top-dressing.

The trial was collaboratively designed by Southern DIRT R&D committee members and staff, Wes Lefroy of Precision SoilTech, and the landholders, Roger and Simon House.  The focus of the treatments was to;

a)  Utilise the most economic source of lime for the landowners,

b)  apply the lime at a range of rates representative of both local practice and industry endorsed practice, and

c)  incorporate the lime with equipment which are known to improve the movement of lime through the soil profile compared to top-dressing; while having minimal complicating factors (i.e. poor seed placement) which are commonly associated with other forms of deep tillage.

The trial is located 12 km north of Kojonup and was chosen for its combination of targeted soil type (forest gravel) and pH range (4.5 – 4.8 CaCl2) up to a depth of 60cm.

 

 

The methods for incorporating lime in the trial are offset discs and one way plough, with knife-points at seeding included as a control.  Both offset discs and one way ploughs are generally used for the shallow incorporation of lime, and in this trial the depth achieved was approximately 10cm for the offset discs and 12cm for the one way plough. Research has shown that these incorporation methods can be more effective than the standard practice of top-dressing lime at increasing soil pH at depth by mixing lime into the soil profile when adequate rates are applied. While the lime is mixed well to the working depth of the implements, neither of these methods have the capacity to incorporate lime to depths beyond 20 cm.

Both offset discs and one way ploughs are considered by local growers as more cost-effective options for incorporating lime when compared to other methods (i.e. rotary spading). Annual plot soil testing and harvest yield will be the primary indicators used to assess how quickly and effectively the various treatments are able to raise pH at depth and increase production on forest gravel soils constrained by subsoil acidity.

EverCrop research reported in this and previous Crop Updates (2010-2014) has built up a sound knowledge base on the viability, performance and economics of pasture cropping and companion annual legume based systems for fragile soils in the Northern Agricultural Region that are marginal for continuous cropping. Collectively, trials at Mingenew and Dandaragan over the past two seasons (2013 & 2014) have demonstrated that subtropical perennial grass pastures lift the overall productivity of deep sandy soils, extend the period of available green feed, convert summer rainfall into feed, reduce the winter and summer weed burden, and increase ground cover.

These experiments provide a framework to allow growers in the Wimmera and Southern Mallee to use soil tests for nitrate N, organic carbon, and soil water to determine firstly, their yield potential, and secondly, whether there is a need for nitrogen fertiliser to achieve that potential.

• No yield differences were observed between the incorporated stubble and the standing stubble plots despite differences being recorded in plant growth during the year.
• The dry spring conditions had an impact on grain yields with no significant difference observed between treatments. 

• Yield differences were observed between the incorporated stubble and standing stubble plots.
• The hot dry conditions during November had a major impact on grain yield.
• Lodging was a problem in all of the plots with the incorporated plots particularly affected.
• At this stage no significat tincrease in soil orgainic carbon was observed.

• Pre-emergent herbicides can cause crop damage. Separation of the herbicide from crop seed is essential for crop safety, which is more easily achieved in knife-point & press wheel seeding systems but considerably more difficult with low soil disturbance single discs.
• Crop stubble can intercept & bind pre-emergent herbicides, which affects crop safety & herbicide efficacy. Low solubility herbicides such as trifluralin have a tendency to bind strongly to crop residues, which reduces the potential for crop damage but also limits its ability to provide effective weed control in situations with heavy stubble load.
• Choose the right herbicide for the job – not all pre-emergent herbicides behave the same so follow label recommendations closely.

Take Home Messages

Whilst the trial didn’t go according to plan there were still some key messages that arose:

• Maximising seed-soil contact is the aim at sowing especially for the larger seeds that require more moisture to imbibe and germinate compared to small seeds.

• Unseasonably low June rainfall hindered establishment of partially sown beans due to a drying topsoil. These may have been

OK under normal June rainfall conditions.

• Hair pinning can be a serious issue when using a disc seeder especially when sowing into wet/ moist lodged stubble.

• Solutions to avoid hair pinning – sow when stubble is dry (good in theory), keep stubble standing, use sharp discs and ensure bar

has sufficient down force to cut through tough stubble.

• Annual medic had lower levels of soil N (kg/ha) remaining in the soil post-harvest compared to balansa clover and subterranean clover at Sherwood.
• Annual ryegrass establishment was greater in crops following wheat, compared to crops following a pasture break crop.
• Overall pasture biomass production was greater at Bordertown compared to Sherwood.
• Wheat yields at Sherwood were greater following balansa clover and subterranean clover, compared to following canola and cereals options, wheat, barley and oats.
• Grain barleys Compass and Rosalind have demonstrated a capacity to produce biomass as a forage or hay option; feed tests need to be considered to ensure they are as favourable as forage options for livestock production. 

• Research funded by the GRDC- SARDI Bilateral Research Agreement.
• Focus on ‘Integrated Farming Systems in the Medium Rainfall Zone’.
• Three field components, long-term rotational trials, targeted agronomic trials and focus paddocks.

• Sow chickpea crops between standing wheat rows.
• Sow the following wheat crop directly over the row of the chickpea crop from the previous year.
• Keep wheat stubble intact and do not spread it across the soil surface.
• This will maximise yield of both chickpea and wheat crops and reduce the incidence of crown rot in the wheat phase of the rotation sequence.
   

• A combination of chemical and non-chemical weed control strategies can extend the life of herbicides and improve the sustainability of intensive cropping systems.
• Windrow burning, crop topping and chaff carts are options which can reduce the ryegrass seed bank without any yield penalty.
• Cutting a cereal crop for hay for one year can significantly decrease ryegrass levels in the following crop.

• Integrated weed management is the best approach for long-term control of herbicide resistant annual ryegrass.
• The most effective cultural control method trialled was mouldboard ploughing which was significantly better than stubble.burning or direct sowing into retained stubble in terms of in crop weed numbers.
• Sakura + Avadex Xtra IBS herbicide regime achieved the best control of annual ryegrass later into the season.
• Crop establishment, wheat yield and grain quality were not affected by the choice of weed control method in this trial.

• The use of Lucerne in the Upper Wimmera catchment and similar areas can be extended away from traditional areas such as river and creek flats.
• Introduction of lucerne into grazing systems lengthens the period of available green feed and can allow for enterprise change such as adding a lamb finishing operation to the farm business.
• Sowing time of lucerne is best suited to late winter.
• Soil testing is important to test for nutrient deficiencies and pH prior to lucerne establishment. Adequate lime and fertiliser should be applied to address deficiencies prior to establishment. Attention must be paid to ensuring that aluminium levels are suitable for lucerne production prior to sowing.
• A sub soil pH test should be taken to ensure that there are no acidity or aluminium toxicity issues at depth which could affect the lucerne plants as their roots penetrate the sub soil.
• Weed control is of critical importance before and during the establishment phase of lucerne pastures.
• Sowing depth of lucerne is important to allow an even germination. Care should be taken not to sow seed too deeply. The seed should be covered by 1 – 2 cm of soil, ensuring good soil contact.
• Control of annual grass and broadleaf weeds is of critical importance during the life of the lucerne stand if maximum production is to be achieved.
• A suitable fertiliser regime including the use of potash needs to be applied to replace nutrients removed by the lucerne system.
• Lucerne pastures can produce high quality hay which can enhance the farm’s production system if kept on farm.

Inter row sowing in no-till systems works well and can increase crop profits for wheat, lentils and canola.

Inter row sowing in no-till systems works well and can increase crop profits for wheat, lentils and canola.

Inter row sowing in no-till systems works well and can increase crop profits for wheat, lentils and canola.

Inter row sowing in no-till systems works well and can increase crop profits for wheat, lentils and canola.

• Zinc deficiency occurs on many heavy textured soils in the cereal areas of Queensland.
• Zinc deficiency is greater after long fallows and much reduced in double crop systems .
• In linseed zinc deficiency has been associated with potassium, manganese and occasionally phosphorus deficiency. But in wheat only zinc deficiency has been recognised.
• Zinc foliar sprays are thought to be the best solution.
• The positive effect of double cropping is thought to relate to root factors.

Soil biota hold the key to sustainable crop production via impacts on processes like suppression of disease outbreaks and the cycling of essential nutrients.

In this trial, burning significantly outyielded six other stubble retention treatments at this site in 2006. Whilst grain quality had little influence on classification in the 2006 drought, the economics of burning showed more that a $100/ha Gross Margin benefit.

On average, the surface retained treatments appeared to yield marginally better across this site. There appeared to be no difference in grain quality between treatments. There appeared to be no significant levels of insect pest or predator numbers in either the assessed standing stubble or the burnt treatment at the crop early emergence stage. There was however twice as many beneficial species in the stubble retained treatment. Insects that were present included both beneficial and harmful earwigs at very low levels, spiders and carabid beetles (that were of importance). Soil water data at crop anthesis indicates that the higher yielding treatments experienced lower soil moisture levels to 60cm, reflecting a possible increase in transpiration from greater crop biomass. Plant available water in the burnt and wider row treatments was higher, but not significantly different.

• In the 2008 season, the two treatments with the poorest plant establishment counts (stubble burning and incorporation) yielded significantly more than the remainder of the standing stubble treatments.
• Incorporation yielded on average 2.4t/ha for the three seasons, 0.2t/ha  greater than standing stubble and cellulose digester, but was not a more profitable option. 
• For the duration of this project, the gross marging outputs suggested that burning was the least profiatble, with all other treatments comparable, with a $300/ha return. With this outcome in a series of dry years, farmers should use what tools they know work best for them in a profitable and sustainable manner to manag crop stubbles in the future. 

• Understanding key drivers and processes in controlling awnless barnyard grass (Echinochloa colona), feathertop Rhodes grass (Chloris virgata), fleabane (Conzya bonariensis L), windmill grass (Chloris truncata) and sowthistle (Sonchus oleraceus L).
• Investigating the impact on weed control of pupae busting and the potential impact of removing this tillage operation.
• Demonstration of integrated weed management principles, including controlling ‘escape’ weeds and the impact on seed set, to encourage industry to adopt the research outputs.
• Glyphosate resistance is emerging in cotton farming systems.

• Differences in C input (dry matter production plus any additions) between the treatments were 24 t/ha at Minnipa, and 31 t/ha at
• Poochera over the last two seasons.
• Wheat at Minnipa produced between 0.5 t/ha of stubble in a poor season (2008) and 8.8 t/ha in a good season (2009).
• Doubling the seeding rate of wheat at Minnipa produced 1.4 t/ha extra stubble compared to the wheat control in 2009.
• Barley and vetch brown manures produced the lowest dry matter at both sites.

The 2006 field trials have again shown that there is a place for new carrier products of root nodule bacteria in our systems, which could be of great benefit to the farmer. These new products in most cases performed as well as the traditional peat slurry carrier. The introduction of these new products offers producers an opportunity to choose the type of delivery system which best suits their business and budget.

• Corresponding to the biomass assessments, the compaction of the Trafficked zone had a notable effect on the crop performance.
• As a comparison of all sites there was an increase of grain yield of between 18 and 46% of the zero traffic area above the paddock assessments.

• Corresponding to the biomass assessments, the compaction of the Trafficked zone had a notable effect on the crop performance.
• As a comparison of all sites there was an increase of grain yield of between 18 and 46% of the zero traffic area above the paddock assessments.

• Corresponding to the biomass assessments, the compaction of the Trafficked zone had a notable effect on the crop performance.
• As a comparison of all sites there was an increase of grain yield of between 18 and 46% of the zero traffic area above the paddock assessments.

• Early zinc uptake can be increased when zinc is applied as soil spray, seed coat or granular fertiliser but this does not necessarily increase yield.
• Products differ markedly in price per kg of elemental zinc so carefully consider your choice to get best value for money.
• Make sure choice of application method fits your farming system: for example if you are no-till then soil spray inefficient as not worked into root zone, foliar spray too late if you have zinc deficient soil as yield losses will already have occurred.
• Some products have short term benefits (seed coats and foliar sprays) and some longer term benefits.

• Winter canola had greater DM production compared to spring canola.
• Time of sowing significantly influenced canola grain yields.
• Grazing Manning did not result in a yield penalty, but grazing Trojan wheat did; need to be careful not to graze outside of the “safe” grazing window.

Irrigated durum wheat can meet DR1 specification

The nitrogen requirement is approximately 50 kg N/t 

Growing durum wheat on a pulse stubble has both disease and nitrogen management benefits

• Although not statistically validated a trend of either higher or lower NDVI’s in the centre of the tram tracks was observed on 7 of the 14 farms investigated.
• The trend to wider header fronts makes the practicalities of redistributing residue evenly back across the width of the header all the more difficult and may accelerate any rate of change in crop performance.
• In the short term CTF producers should target even redistribution of crop residue across header widths
• Further work is needed and the author would welcome collaboration from others in helping to design a future experiment and statistical analysis.

• Although not statistically validated a trend of either higher or lower NDVI’s in the centre of the tram tracks was observed on 7 of the 14 farms investigated.
• The trend to wider header fronts makes the practicalities of redistributing residue evenly back across the width of the header all the more difficult and may accelerate any rate of change in crop performance.
• In the short term CTF producers should target even redistribution of crop residue across header
  widths
• Further work is needed and the author would welcome collaboration from others in helping to design a future experiment and statistical analysis.

• The fluid fertiliser system increased yield and dry matter production at both sites.
• The added carbon treatments with increased microbial activity have not increased grain yield in 2011.

• Two lontrel resistant biotypes have been identified in overseas vetch populations.
• Risk of resistance in Australian farming systems is low, but management practices to avoid lontrel resistant vetch should be implemented.
• Be more wary of wild vetch populations as opposed to volunteer vetch.

Crop stubbles provide a valuable feed source for stock over the summer period. The results from this trial indicate that grazing stubbles does not reduce either the amount of soil water stored during the summer fallow period or subsequent crop yield. In low rainfall environments, it is rarely possible to grow sufficient stubble to improve summer fallow efficiency by reducing evaporation (>5t/ha): growers should make use of this valuable feed source. Growers should maintain at least 70 per cent stubble cover (about 2t/ha of cereal stubble) to minimise the risk of wind erosion.

This quick look at rainfall patterns does not prove whether there is, or isn’t, a change t to farming in the dry mid 1990s nwards. High rates of N and no fallowing worked during the wet periods but have ot worked very well in the last decade. We need to adapt our farming practices to prevent over-supplying inputs in low rainfall years. This must be done in a way which does not compromise potential yield if it turns out to be a wet season. We cannot change crop type once sown but can increase the proportion of cereals and fallow if there is no stored soil moisture at seeding. We can also reduce P rates in accordance with past applications and with potential yield AND we can delay N inputs until later on the season. Refer to numerous articles on these topics in this manual. occurring in our climate and rainfall patterns. It does show that, although not desirable, it is not unusual to have a run of dry years – it could be just chance or a normal periodic event. Other long periods of dry seasons occurred at the start of the 20th century (1897 to 1906), mid 1920s to early 1930s; and the longest dry spell between 1938 and 1950.

The use of a Speed tiller to incorporate stubble did not appear to have any negative impacts in the mixed farming systems in the medium rainfall zone in the South-East of South Australia in a very dry season. There was high paddock variability, due to moisture stress, which would have impacted the results.

• Weed control is essential for effective kikuyu establishment.
• Two sprays of round up is the ‘safest’ bet although you do lose some grazing value and may have difficulties with seeding at the optimum time if the paddock is too wet to spray early.
• Further work is required to quantify the benefits of application of TM 21 on kikuyu pastures on KI.

• Weed control is essential for effective kikuyu establishment.
• Two sprays of round up is the ‘safest’ bet although you do lose some grazing value and may have difficulties with seeding at the optimum time if the paddock is too wet to spray early.
• Further work is required to quantify the benefits of application of TM 21 on kikuyu pastures on KI.

• Following drought affected cereals, labile P concentration was greater in the crop row than in the inter row.
• There is potential to exploit carry over P following 2006.
• In addition this may also have implications for those with auto steer systems with 2cm accuracy to seed into higher concentration of P in last years failed or low yielding crops.

• Growers and advisers should be vigilant in applying protective fungicide sprays in chickpea and lentil crops for ascochyta blight.
• Many current and minor use permit fungicides trialed at Hart in 2017 provided good preventative control (less than 10% of plants infected) for ascochyta blight including; chlorothalonil, Aviator Xpro, Cabrio and Captan.

• The tolerance of Nipper and Boomer to commonly used herbicides in terms of grain yield was similar to Nugget.
• Herbicide treatments containing metribuzin applied PSPE, generally caused the greatest yield loss to all varieties.

• Grain yields averaged approximately 25% higher in plots sown on 30 cm the row spacing system (standing stubble) compared with the 19.5 cm row spacing system.
• Varieties responded differently to changes in row spacing with yield improvements ranging from 15%-50%.

• The low mean yield at this site (0.69 t/ha) was largely attributed to drought, and was exacerbated by late sowing conditions and suspected herbicide damage.
• Small yield and normalised difference vegetation index (NDVI) increases closely reflected increases in seedling density. 
• PBA Giant and PBA Jumbo2 produced more grain and green foliage cover, closely followed by PBA Ace. These ranking reflect the long term, multi environment trial (MET) yield analysis for lentil varities for this region (Figure 5).
• Care should be taken when applying and incorporating herbicides on acidic, light textured soils, particularly when straw is present. Under these conditions, it is advisable to sow deeper to position seed below the herbicide band. 
• Furher lentil sowing rate investigations are required in this region to better understand variety responses to plant density, earlier sowing, season conditions and different environments.    

• Earlier sowing generally resulted in highest yields. Similar to Minyip ,there were no major differences in yield with wider row spacings (30cm c.f. 19.5cm).
• However, an increase in pod height in the wider rows and standing stubble was only recorded at the second sowing date.

• Average grain yields across all varieties in retained stubble treatments (Slashed and Standing) were equal or greater than Removed stubble treatments in all years of testing.
• There was generally a greater yield response from the Standing treatment than the Slashed treatment.
•  The yield response from stubble retention was generally the greatest at the Late sowing date.

Seeding rate of lentils in the Mallee could be lowered from 120 to 80 plants/m2, particularly with new disease resistant varieties sown early. Lentils were profitable in the mallee, producing up to $653/ha at Kulwin and $433/ha at Curyo.

• Modest autumn grazing of no-till crop stubbles sometimes leads to small measurable increases in surface soil bulk density.
• In two seasons, on soils in the Mallee and Wimmera, modest autumn grazing of no-till crop stubbles had no measurable effect on crop yield, quality or weed seed burial.

• For the first time sheep grazing behaviour in a Mallee paddock was monitored and mapped using GPS tracking collars.
• Sheep grazed the entire stubble paddock as they sought out spilt grain during the summer fallow, but they preferred to graze on sandy soil types first.
• While grazing a vetch pasture in the same paddock, livestock spent 50% of the time grazing only 25% of the paddock and 25% of the paddock was not utilised. (iv) At least $4000 profit was foregone from the paddock through the under-utilisation of the vetch pasture.
• Within-paddock fencing technology in large Mallee paddocks has the potential to capture this potential profit by improving feed utilisation.

• For the first time sheep grazing behaviour in a Mallee paddock was monitored and mapped using GPS tracking collars.
• Sheep grazed the entire stubble paddock as they sought out spilt grain during the summer fallow, but they preferred to graze on sandy soil types first.
• While grazing a vetch pasture in the same paddock, livestock spent 50% of the time grazing only 25% of the paddock and 25% of the paddock was not utilised.

Light to moderate grazing of sheep on no-till stubbles in autumn is unlikely to have detrimental impacts on crop growth in the following season.

• Seeding system had a significant effect on wheat grain yield with the disc treatment averaging 4.1 t/ha compared to the no-till and strategic systems which averaged 3.5 and 3.4 t/ha, respectively. 
• The higher nitrogen treatments increased grain protein levels and screenings, while decreasing test weight across all seeding systems.

• Seeding systems did not affect wheat grain yield, averaging 5.3 t/ha.
• Good rainfall and cool temperatures during grain fill increased yield potential and the higher N rate resulted in a 1.2 t/ha yield advantage.
• Available soil N pre-seeding ranged from 80 – 190 kg N/ha with 75 kg N/ha more accumulated under the high N rate.

Five management strategies were compared: stubble fully retained (SFR); cut and baled (SCB); incorporated with Lemkin discs (Lemkin); Burnt; and stubble digester applied with stubble incorporated. Increased ground cover resulted in large delays in establishment.The different stubble treatments had no significant effect on grain yield.Some long term benefits from full retention of stubble are already evident with significant increases in earthworms and a trend towards decreased resistance to root penetration.

• There was no significant difference between seeding systems or level of nutrition on grain yield or oil content.
• Soil available N was the same for all seeding systems pre-seeding however, the no till treat had released more available soil N.
• In-season more available N was measured in the high nutrition treatment compared to the medium.

• Changing rotation and nutrition have changed the microbial population activity and diversity but not developed disease suppression after seven years.
• One year of wheat in 2009 resulted in high Rhizoctonia inoculum regardless of previous rotation or fertiliser histories.
• Take-all has increased in the continuous cereal district practice treatment to severe levels; higher nutrition treatments give the plants the ability to cope better with these increased disease levels.
• The high input systems have continually yielded higher than the other systems, but inputs of N have not matched production levels completely so soil reserves of mineral N are now lower in these treatments.
• In good seasons the high input treatments have shown that district practice performance is severely limited by inadequate nutrition.

• The higher input brassica break system had higher cereal yields than the other systems in 2009.
• Rhizoctonia inoculum levels were higher under the continuous cropping systems compared to the medic pasture and brassica break crops.
• The different rotations and fertiliser systems have resulted in differences in the microbial community (number) and microbial diversity (their ability to use different sources of carbon).
• Disease suppression is still the same in all rotations.

• No till treatments have been higher yielding and more profitable in continuous cropping rotations. Cultivation has increased yield and profit in 18 month fallow rotations.
• Two cereals followed by a break crop of either fieldpeas or canola no till has been the most profitable rotation. Interestingly 16 years continuous wheat has not been too far behind.
• Weed spectrum and numbers have changed dramatically within rotations and tillage methods. Interestingly no till treatments have hosted less weeds than cultivated treatments.
• One year of no pre emergent herbicide has taken the trial back 6 years and allowed large numbers of ryegrass to again become established and set seed.

• After 18 years there was no standout rotation, in terms of profitability, in any given season. All  rotations had their pros and cons in both wet and dry years. Therefore having a mix
  of rotations and doing things on time is a recipe for a resilient business.
• The most profitable rotation for the duration of the trial was the continuous cropping rotation, which included two wheat crops followed by a pulse crop in a no-till system. The addition of the pulse crop every third year was beneficial, especially for adding extra nitrogen, however added issues such as broadleaf weed blowouts with weeds like fumitory.

• No till treatments, for all rotations, were slightly higher yielding than the conventional tillage
  treatments for wheat. The yield of peas, in rotation 2, was very low in this trial as a result of
  the season and Sakura damage.
• Rotations including a fallow, such as the WFW treatment, had lower weed numbers compared
  to continuous cropped rotations. The continuous wheat rotation, both conventional and no till
  treatments, had a large number of ryegrass, even with Sakura.
• Profit and income for 2015 was highest in the no till wheat/ley/fallow/wheat rotation, and lowest in Rotation 2.
• 17 years of no till wheat on wheat is still second for profitability.

• Five stubble management strategies were compared: fully retained, cut and baled, burnt and incorporated with Lemkin or offset discs. 
• Grain yield from the burnt plots was significantly higher compared with stubble retained (fully retained and cut and baled) and both incorporation treatments were significantly higher yielding than where stubble was fully retained. It is likely that this effect is a result of increased stubble from retained treatments leading to poorer plant establishment.
• Fully retained stubble resulted in significant soil improvements i.e. increased soil moisture (particularly early in the season), higher invertebrate and microbial populations and improved soil physical characteristics.
• Rain at the end of the season may have masked potential yield benefits from improved soil moisture with retained stubble treatments.   

• Five stubble managmenet strategies were compared: fully retained; fully retained with higher sowing rate; cut and baled; burnt and incorporated with Lemken discs.
• Fully retained stubble resulted in some soil improvements such as increased worm populations.
• Grain yield from plots where stubble was retained (fully retained ad cut and baled) tended to produce higher yields compared with plots where stubble was burnt. The wet season and irrigation may have masked any greater potential yield benefits from plots with retained stubble.

Barley grain yield was not affected by tillage treatment averaging 4.25 t/ha. The medium nitrogen level increased grain yield by 0.61 t/ha compared to the high nitrogen level

• Wheat grain yield was not significantly different between seeding systems or level of nitrogen, averaging 5 t/ha.
• The high nutrition treatment increased grain protein.
• The high nutrition treatments had accumulated 28 kg N/ha more soil available nitrogen compared to the medium treatments to a depth of 60 cm.

After 8 years of trial work on a Mallee clay loam with subsoil limitations:

• In only 2 years did yields increase after applying P fertiliser,
• the site has remained responsive at nil and 5P treatments, but maintaining rates >5kg P/ha did not produce any extra yield,
• in 2010 there as a 25% increase in wheat yield between nil P and where P had been applied (at rates 5kg P/ha or higher),
• the 5kg P/ha treatment provided the highest net income, and
• soil Colwell P together with PBI accurately estimated the response seen in 2010.

• After nine years, applying more than 5kg P/ha had no impact on grain yield in 2011.
• Consistently applying 5kg P/ha has been the most productive and profitable rate used.
• The DGT soil P test will undergo commercial testing at CSBP laboratories in 2012.

• In a Morgan pea hay crop, there were no dry matter differences between any of hte P fertiliser rates in 2009.
• The most profitable application of P on average between 2003 and 2009 has been zero P/ha on a site with a strong fertiliser history and initial soil P Colwell of 41mg/kg.
• A rate of 5kg P/ha per year produced the second highest net income with the least amount of risk.

Phosphorus responses were undertaken in 2004 on a barley crop. This is a long-term trial to determine the effect of a range of fertiliser application rates of phosphorus (P) on long-term grain yields and soil phosphorus reserves. Results indicate that in paddocks with a good phosphorus history little response, in terms of grain yield and protein, will be gained from higher rates of P. However grain yields and protein were significantly higher where some P was applied compared to no P.

• Since this trial began in 2003, there has been no significant economic response to applied P. The most profitable treatment over five years was where either no P or 5kg P/ha had been applied.
• If considering reducing P rates in 2008, it is important that the amount of P that has been applied and removed over a 3-4 year period is calculated. If the P removal is not greater than P inputs then you can consider reducing P rates.
• The 5kg P/ha rate maintained a neutral P balance after the 5 years, whereas the control had a negative balance of just under 20kg P/ha. The higher rate treatments failed to utilize applied P and subsequently accumulated a positive balance greater than 20kg P/ha.

• There was no significant yield difference between any of the P rates in 2008
• The most profitable application rate of P on average between 2003 and 2008 has been zero on a site with a strong fertiliser history and initial soil P Colwell of 41ppm
• Maintenance rates of 5kg/ha, produced the second highest net income with the least amount of risk
• Avoid making fertiliser decisions on ‘gut feel’. Make use of tools such as soil tests and nutrient balances to determine P rates in 2009.

• Crop water use and soil analysis values were very similar between the sites comparing long term reduced tillage and stubble retention.
• Reduced tillage and stubble retention has significantly contributed to increasing organic carbon levels at these sites.
• The grain yields of wheat were greatest at the sites with higher water use efficiency for each location.

• Crop water use and soil analysis values were very similar between the sites comparing long term reduced tillage and stubble retention.
• Reduced tillage and stubble retention has significantly contributed to increasing organic carbon levels at these sites.
• The grain yields of wheat were greatest at the sites with higher water use efficiency for each location.

• Crop water use and soil analysis values were very similar between the sites comparing long term reduced tillage and stubble retention.
• Reduced tillage and stubble retention has significantly contributed to increasing organic carbon levels at these sites.
• The grain yields of wheat were greatest at the sites with higher water use efficiency for each location.

The results from this trial show the importance of ripping below the hard pan with deeper ripping. The hard pan at this site measured to a depth of 400mm prior to the ripping treatments going in. Ripping to 300mm, without spading, has not improved yield in either of the first two seasons as plant roots are slowed through the hard pan. For return on the dollars spent deep ripping it is important to understand where the hardpan is in your paddock before starting the program.

It is likely that the topsoil slotting plates are impacting the inter-row soil strength during the ripping process. Therefore the design needs investigation. It may be that additional shatter is required through winged points allowing the plates to pass through with less impact.

Monitoring of this trial continues during 2017 and 2018 seasons.

• Autumn removal of lucerne significantly decreased subsequent winter crop yields compared to spring removal of lucerne.
• Crops sown after spring removal of lucerne yielded the same as the crops grown in a continuous crop rotation.
• The crop yield penalty from autumn removal only lasts for one year.
• Apart from Grazon, all other herbicide treatments gave unacceptable lucerne control.
• Cultivation in combination with other herbicides will increase lucerne control by  20 to 30%. 
   

Lucerne (medicago sativa) is being utilised for a range of benefits in modern farming systems. This includes the incorporation of phase farming principles into dryland cropping systems within the Mallee and Wimmera. In the Mallee, recharge rates vary from 5 to 35mm per year under traditional cropping systems. The principle of phase farming involves the tactical insertion of a lucerne pasture in a crop rotation to retrieve deep soil moisture and create a dry band below the rootzone of annual crops.

Using a combine harvester to manage stubble at harvest was expensive and exposed crops to greater risk of weather damage.  Harvesting tall and inter-row sowing was the cheapest form of stubble management and also gave good establishment.  Burning is cheap and effective at removing stubble, and allowed excellent establishment and greater early vigor for competition with weeds, but may not suit all paddock types.

• In 2017, don’t let stubble compromise the big things (weeds, disease, timeliness).