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Research & Development

An increasing trend by Western Australian growers to use grain bags after harvest has led to new research into the impacts of this type of on-site storage on cereal seed quality.

Bagging Grain No Impediment To Quality

Author: Natalie Lee

Date: 12th October, 2018

image of grain bag
Research with GRDC investment being carried out by SEPWA is finding grain can be stored in these types of grain bags at harvest with limited risks of quality damage or poor germination in retained seed for the following year. PHOTO: SEPWA

Key Points

  • Use of on-farm grain bags at harvest is gaining popularity in WA to help manage logistics
  • Research shows grain can maintain acceptable moisture levels during summer storage in grain bags
  • Seed germination rates of 99-100 per cent after summer grain bag storage were recorded in trials that have GRDC investment.

 

An increasing trend by Western Australian growers to use grain bags after harvest has led to new research into the impacts of this type of on-site storage on cereal seed quality.

Results to date from the South East Premium Wheat Growers Association’s (SEPWA) Bagging grain profits project are giving this tactic a tick of approval, with minimal evidence of adverse impacts on grain quality or seed germination rates after planting the following year.

The group conducted trials of grain bags across the Esperance region during the 2017-18 harvest, as part of a suite of Grains Research and Development Corporation (GRDC) investments into local issues that have been identified by grain growers as impacting on their profitability.

SEPWA’s research will be repeated during this year’s harvest period and include monitoring grain quality factors such as seed moisture, protein levels, temperature, colour and germination, and assessing any market liability risks.

SEPWA project officer Aidan Sinnott said results from last summer indicated daytime maximum temperatures, including quite big fluctuations from low-20⁰ Celsius levels up to the mid-40⁰C range, did not have a big effect on temperatures inside the grain bags.

He said across the trial sites, and after about 40 days of storage in the bags, barley and wheat grain moisture was maintained at industry acceptable levels of about 13-14 per cent and grain quality was not adversely impacted by this type of storage in the summer conditions.

Mr Sinnott said at one location, wheat did heat up more than barley when monitored in grain bags for 38 days at an average daytime temperature of about 20⁰C, but not to a level that impacted on its key quality parameters.

Part of the Bagging grain profits project was to assess the germination rates of cereal seed retained in grain bags after sowing in 2018.

Across all trial sites, germination rates were 99-100 per cent for this seed, some of which was stored in grain bags for up to 74 days.

“Overall, there was very little effect on seed germination percentages for wheat and barley stored in grain bags in the conditions experienced in the 2017-18 harvest and summer period,” Mr Sinnott said.

“During the coming harvest, we plan to extend the storage period of grain in bags and add other crop types to our evaluation.

“At the end of the two-year GRDC-SEPWA project, we hope to have developed comprehensive tips for using grain bags and best-practice guidelines for industry stakeholders down the supply-chain, including how to manage any potential grain quality risks.”

 

Mr Sinnott said the use of grain bags for on-site storage was now a recognised management tactic in WA, providing logistical advantages for growers in allowing them to fast-track harvest operations, manage grain moisture and quality and capture freight cost advantages.

“SEPWA advocates early harvest in the South Coast region to optimise grain quality and crop value,” he said.

“Grain bags enable management of moisture and quality parameters prior to grain leaving the farm, or can be used for storing retained seed for subsequent planting.

“Use of these bags also offers opportunities for growers to access grain quality upgrades and extend the truck freight period to further reduce peak harvest grain freight costs.”

GRDC grower relations manager – west, Lizzie von Perger, said the SEPWA-led Bagging grain profits project was the direct result of this issue being raised as a challenge by WA growers.

“It is vitally important that GRDC responds to emerging issues, such as optimising results from the use of innovative grain storage tactics, in a timely manner,” she said.

While advances in agronomy and the performance of individual crops have helped grain growers to maintain their profitability, current farming systems are underperforming; with only 30% of the crop sequences in the northern grains region achieving 75% of their water limited yield potential.

Can Systems Performance be Improved by Modifying Farming Systems? Farming Systems Research - Billa Billa, QLD

Author: Andrew Erbacher and David Lawrence (GRDC)

Date: 25th July, 2018

 

Take home messages

  • Different farming systems comparisons conducted over 3 years at Billa Billa QLD have shown that the baseline system (wheat-barley-wheat) has so far returned the highest gross margin ($2.77) per mm rainfall.
  • Increasing or decreasing cropping intensity has returned similar gross margins, but had low returns in 2016/17 summer.

Project background

While advances in agronomy and the performance of individual crops have helped grain growers to maintain their profitability, current farming systems are underperforming; with only 30% of the crop sequences in the northern grains region achieving 75% of their water limited yield potential.

Growers are facing challenges from declining soil fertility, increasing herbicide resistance, and increasing soil-borne pathogens in their farming systems. Changes will be needed to meet these challenges and to maintain the productivity and profitability of our farming systems. Consequently, the Queensland Department of Agriculture and Fisheries (QDAF), New South Wales Department of Primary Industries (NSW DPI) and Commonwealth Scientific and Industrial Research Organisation (CSIRO) are conducting an extensive field-based farming systems research program, focused on developing farming systems to better utilise the available rainfall to increase productivity and profitability, with the question;

Can systems performance be improved by modifying farming systems in the northern region?

This research question is being addressed at two levels by the northern farming systems initiative; to look at the systems performance across the whole grains region, and to provide rigorous data on the performance of local farming systems at key locations across the region.

Research began in 2014 with local growers and agronomists identifying the key limitations, consequences and economic drivers of farming systems in the northern region; assessing farming systems and crop sequences that can meet the emerging challenges; and developing the systems with the most potential for use across the northern region.

Experiments were established at seven locations; a large factorial experiment managed by CSIRO at Pampas near Toowoomba, and locally relevant systems being studied at six regional centres by QDAF and NSW DPI (Table 1). Several of these systems are represented at every site to allow major insights across the northern region, while the site specific systems will provide insights for local conditions.

The following report details the systems being studied in Billa Billa (Goondiwindi), how they are implemented locally and the results after the first three years. Data and system performance indicators have been developed to compare performance across sites.

Table 1. Summary of the regional farming systems being studied at each location in the northern farming systems initiative.

 

   

Billa Billa - 2015 to now

The Billa Billa site is located 50 km north of Goondiwindi on the Leichhardt Highway. The soil is a grey vertosol. The original belah and brigalow trees were cleared and the paddock used as a long-term pasture before being developed for crops in the late 1990s. The previous paddock management has meant there was 360 kg N/ha available at the beginning of the trial.

The paddock grew chickpeas in 2014, so was quite bare prior to commencing the trial in autumn 2015. All of the systems were planted to wheat in the first season to provide stubble cover, yielding 4.7 t/ha. After harvesting this crop, the higher soil fertility system had 75 t/ha of compost broadcast across it to supply an additional 10 t/ha of carbon to this system, which increased the soil carbon by 27% in the top 30 cm of soil. Deep phosphorus was then applied to all of the cropping systems supplying 70 kg P/ha applied in the form of Granulock® Z. After 2015, rotations in the different systems have been quite diverse (Figure 1).

The baseline system was planted to barley in 2016, wheat in 2017 and is planted to chickpea in 2018 (Figure 1).

The summer of 2015-16 was dry with storm rain contributing to the majority of the profile moisture accumulation. The higher crop intensity system triggered an opportunity to be double cropped to mungbean on 15 January. The next effective rainfall this crop saw was after spraying out, so yielded 0.35 t/ha (Figure 2). This double-cropped mungbean crop was planted with the same starting water as the baseline system, which was held in fallow over summer and planted to barley in 2016. This gave the higher crop intensity system a fallow efficiency advantage of 71% versus 30% in the Baseline system(Figure 5). However, differences in the timeliness of in-crop rain had a major impact on the yield outcomes of the mungbean and barley crops (Figure 2).

Autumn 2016 was also dry, requiring faba bean and field pea to be deep sown in the higher legume and higher crop diversity systems respectively. Baseline, higher nutrient supply and higher soil fertility systems were planted to barley on 1 June (Figure 1), with the season remaining quite wet until November. The faba bean and field pea crops matured in early October, and had a wet harvest with a full profile of water, allowing a double crop opportunity in both of these systems. However, the barley in 2016 (baseline, higher nutrient supply and higher soil fertility systems) lodged and put out late tillers, so was harvested mid-November with weather damaged grain. Grain yields averaged 6.3 t/ha for barley and 3.45 t/ha for faba bean and field pea (Figure 2). The yield per mm of water used (water use efficiency) of the two pulse crops were similar to each other, but lower than the barley grown in the same season (Figure 5).

Differences in the economics of the systems to date have largely been driven by the high yields of the 2016 winter crops (Figure 3). The high starting available nitrogen levels at this site has allowed the baseline, higher nutrient supply and higher soil fertility systems to grow 11 t/ha of cereal grain over the first two years, without the expense of nitrogen fertiliser. As such, these three systems have been the most profitable, with the only difference being a higher starter P fertiliser rate in the two higher nutrient systems.

The higher legume and higher crop diversity systems were both planted to pulses in winter 2016 that yielded similarly to each other, but the value of faba bean vs field pea meant the faba bean income and $/mm was similar to the much higher yielding barley, whereas the field pea was quite a bit lower (Figure 3 & 4). The pulse crops in 2016 appear to have fixed nitrogen despite the high starting N. They have similar nitrogen removed in the grain to the barley crops but have an extra 50 kg N/ha left in the soil profile post-harvest. Add to this, the early maturity date of the pulses left an extra 150 mm plant available water, which provided an opportunity double crop. However the dry summer that followed provided poor returns on that double-crop.

The lower intensity and higher intensity systems were planted to sorghum on 15 October, with 200 mm and 120 mm plant available water (PAW) respectively. With only 80 mm in-crop rainfall, these crops were low yielding at 1.5 t/ha and 0.8 t/ha (Figure 2). These yields both lined up with the APSIM predicted yield for the driest 10% of years, for their starting plant available water.

Apart from the 2015 wheat crop that is common to all systems, this sorghum crop was the only crop grown in the low crop intensity system from November 2015 to May 2018, whereas the higher crop intensity system grew three crops to achieve similar cumulative gross margins, with a fourth (sorghum) crop putting the higher crop intensity system slightly ahead. The major commonality in these two systems, that is different to the other systems, is all the crops grown after the initial wheat crop have had received below average in-crop rainfall. Two of these crops were grown in the driest 5 % of seasons for Goondiwindi. As a result the higher crop intensity and lower crop intensity systems are providing the lowest economic returns to date.

After 2016 winter crop was harvested with a full profile of water, the higher legume and higher crop diversity systems were planted to mungbean and sorghum respectively at the next planting opportunity, which wasn’t until December (Figure 1). With no effective rainfall before flowering, the mungbean yielded 0.15 t/ha, whereas the sorghum held on to take advantage of autumn rain for a yield of 1.5 t/ha, harvested in July.

The three systems that grew barley in 2016 were all planted to wheat in May 2017. The higher crop intensity system was also double-cropped to wheat at the same time. This crop received 25 mm rainfall prior to maturity, but received a further 83 mm before it could be harvested. The fallowed systems (baseline, higher nutrient supply and higher soil fertility) yielded 1.7 t/ha on average and the double cropped wheat (higher crop intensity) yielded 1.4 t/ha. These systems had similar crop water use efficiencies (WUE) of 12.5 kg/mm on average (Figure 5). The difference in yield is reflecting differences in starting plant available water.

The mungbean grown in the higher legume system had only dried the top 30 cm of soil, so was one rainfall event off being planted to wheat. With the dry winter this did not eventuate, but 80 mm of rain in October allowed it to be planted to spring sorghum with a good profile of plant available water. This sorghum was looking good with 200 mm of in-crop rain, but a dry January capped the yield at 2.9 t/ha with 40% screenings.

The wet spring in 2017 allowed the higher intensity system to be double-cropped again to sorghum. This crop had a dry start, but 150 mm in February and March allowed it to tiller again for a yield of 2.4 t/ha, harvested in May.

Six systems have been planted to winter crops in 2018 (Figure 1). Higher crop diversity has been planted to canola and lower crop intensity to wheat, both after long fallows. Baseline, higher nutrient supply and higher soil fertility were planted to chickpeas after a short fallow and higher legume double-cropped to chickpeas. This leaves only higher crop intensity in fallow, having received no rain from sorghum harvest to the end of June 2018.

Picture shows timing of crops grown at the Billa Billa farming systems trial, presented on a time scale.Figure 1. Crops grown at the Billa Billa farming systems trial, presented on a time scale. The coloured sections are planting to harvest of each crop, and the grey bars are fallow periods.

Picture is a column graph shows cumulative grain yields of the seven grain systems at the Billa Billa farming systems trial.

Figure 2. Cumulative grain yields of the seven grain systems at the Billa Billa farming systems trial

Graph shows cumulative cash-flow from the seven grain systems at the Billa Billa farming systems trial. This shows the actual production costs and incomes, based on 10 year average commodity prices, over time for each of the systems.Figure 3. Cumulative cash-flow from the seven grain systems at the Billa Billa farming systems trial. This shows the actual production costs and incomes (based on 10 year average commodity prices), over time for each of the systems.

Picture shows gross margin per mm of rainfall for each crop grown, including the preceding fallow period, and total for each system, up to the harvest of the last crop. Figure 4. Gross margin per mm of rainfall for each crop grown, including the preceding fallow period, and total for each system (up to the harvest of the last crop). The coloured bars represent the crops depicted in Figure 2.

Picture shows crop water use efficiency and fallow efficiency, overlaid onto the crop durations represented in Figure 2.

Figure 5. Crop water use efficiency and fallow efficiency, overlaid onto the crop durations represented in Figure 2. The value in the coloured bars is the kg of grain produced per mm of plant available water used + in-crop rainfall. The value in the grey bars is the proportion of rainfall available at planting of the next crop.

Table 2. Grain pricing used in calculations based on median prices over the past ten years, less $40/t cartage costs, 
for selected crops

 

Acknowledgement

This trial is part of a collaboration between the Grains Research Development Corporation (GRDC) Queensland Department of Agriculture and Fisheries (DAF), New South Wales Department of Primary Industries (NSW DPI) and Commonwealth Science and Innovation Research Organisation (CSIRO). DAQ00192.

Grain growers in Queensland and New South Wales are being encouraged to consider the potential impact of residual herbicides as they weigh up what to plant this summer.

Consider Herbicide Status Ahead of Summer Crop Planting

Author: Toni Somes (GRDC)

Date 10th August, 2018

 

Grain growers in Queensland and New South Wales are being encouraged to consider the potential impact of residual herbicides as they weigh up what to plant this summer.

Experts warn dry conditions across much of eastern Australia’s grain belt through winter may have prolonged the efficacy of residual herbicides applied in paddocks earlier in the season.

image of sprayer herbicide

Dry conditions during winter may mean herbicides are present in the soil in greater concentrations then growers would usually expect going into summer planting.

 

Grains Research and Development Corporation Crop Protection Officer – North Vicki Green said the simple fact was herbicides generally needed moisture to breakdown.

“The ongoing dry conditions during winter may mean herbicides are present in the soil in greater concentrations then growers would usually expect going into summer planting,” she said.

“This is not a dire situation, rather it just means growers and their advisers may have to look more closely at crop choice and variety selection ahead of planting.

“Most growers will be aware of the potential risks of residual herbicides in a season like this, but GRDC do have up-to-date information available if people want guidelines to soil behaviour with regard to pre-emergent herbicides.”

Mrs Green said when it did rain growers could also use the emergence of specific weeds as an indicator to what herbicides were still active in the soil.

“Unfortunately, when it rains weeds are usually the first things to respond, the upside is growers can use what weed types emerge as an indicator of what residual herbicides are still in the soil,” Mrs Green said.

The GRDC is committed to building grower and advisor knowledge about weed management and more specifically herbicides and their performance in different soil types under different seasonal conditions.

In recent years the GRDC have run a series of workshops, aimed at enhancing industry knowledge of herbicides. The workshops were co-ordinated by Independent Consultants Australia Network’s (ICAN) Mark Congreve, who has also developed technical manuals to complement the workshops, explaining the science that underpins how herbicides work.

“Greater knowledge of how herbicides work enables grain advisors to better optimise their advice to growers on herbicide use,” he said.

“Manuals and training covered both the soil behaviour of pre-emergent herbicides and the modes of action of post-emergent grass herbicides.

“In the pre-emergent workshop this included volatility, photodegradation, influence of organic matter, soil binding coefficients and cation exchange capacity of the soil. Also, water solubility, breakdown pathways and DT50 values and how these product features coalesce to inform how different herbicides behave in the soil.

“For the post-emergent herbicides, we covered how different modes of action work, herbicide entry through the leaf, translocation and metabolism. The complexities of herbicide resistance and the implications these factors have in optimising performance of particular modes of action.”

Mr Congreve said more than 1000 advisors and growers attended the 57 workshops held across Queensland and NSW.

“The feedback post the workshops was very positive and supports the GRDC’s decision to invest in industry training,” he said.

“The broadacre agronomists who attended the workshops reported that the material presented was informative, easy to understand, had practical application and was complemented by the comprehensive technical materials that were part of the package.

“Importantly the material presented proved to be beneficial to both highly experienced and graduate agronomists.”

Mrs Green said the take home message message from the series of workshops was both growers and agronomists appreciate opportunities to learn new information and build on their knowledge in areas that have practical application in their day-to-day work.

“We were impressed by the feedback from workshop attendees and it has been the catalyst for ongoing GRDC investment in this area,” she said.

“The GRDC is committed to building industry capacity and that means investing in agronomists and growers so they have the skills and knowledge needed to guide on-farm management decisions that influence profitability.”

Mrs Green said the value advisors put on the technical manuals, developed as part of the workshop series, has also prompted the GRDC to make online versions available to all interested stakeholders.

“When advisors and agronomists tell us something is valuable and worth having we listen, hence our decision to make technical copies of the manual available beyond workshop attendees.”

Image of flaxleaf fleabane

Controlling the weed, flaxleaf fleabane, continues to be a challenge for grain growers in Queensland and New South Wales, but research has proved targeting smaller plants during the winter fallow or winter crop phase is key to an effective management strategy.

Paddock Practices: Why is Winter the Best Time to Control Fleabane

Author: Toni Somes, GRDC

Date: 14th Jun 2018

Controlling the weed, flaxleaf fleabane, continues to be a challenge for grain growers in Queensland and New South Wales, but research has proved targeting smaller plants during the winter fallow or winter crop phase is key to an effective management strategy.

Six tips for effective fleabane control:

  • Management in winter (crop or fallow) can be more effective than summer
  • Increase crop competition with narrow row spacing and or higher planting rates
  • Consider strategic cultivation for seed burial or for salvage management
  • Utilise residual chemistry where possible and control ‘escapes’
  • Including 2,4 D or picloram/2,4-D in the first application is a critical for consistent double-knock control
  • Control escapes and prevent weed seed set.

 

Image of flaxleaf fleabane
Research has shown flaxleaf fleabane management is often more effective during winter, both in crop or fallow.

An investment by the Grains Research and Development Corporation (GRDC) into trials conducted by the Northern Grower Alliance (NGA) found fleabane management improved dramatically when grower focus shifted from controlling the weeds in summer fallow to using fleabane control tactics during winter cropping at pre-plant, in-crop and post-harvest stages or in winter fallows.

NGA’s Richard Daniel said flaxleaf fleabane (Conyza bonariensis) control had become an increasingly complex and expensive weed for northern grain growers, as a result of the industry’s heavy reliance on glyphosate and due to the wide spread implementation of no-till or reduced tillage farming systems.

“For nearly two decades, fleabane has been a major weed management issue in the northern cropping region,” Mr Daniel said.

“Factors that make fleabane a major weed includes the fact it is a prolific seed producer, with each plant producing up to 110 000 seeds; it is windborne and occurs in fallows, summer and winter crops and pastures; is difficult to control with herbicides with some populations glyphosate resistant; and the weed can emerge throughout the year.”

Mr Daniel said one of the key issues leading to fleabane being such as problem was that knock-down control of large plants in the summer fallow was expensive and delivered variable results.

“Glyphosate resistance has been confirmed in fleabane, but resistance status is variable with many samples from non-cropping areas still well controlled by glyphosate, whilst increased levels of resistance are found in fleabane in reduced tillage cropping situations.”

So what are the control and management options for growers?

Monitoring

Image of fleabane
Germination of fleabane can occur all year round when wet conditions and temperatures of 10-25°C occur, with fleabane often emerging with winter crops or during the winter fallow in the northern regions.

Monitoring is a key part of weed management but it is particularly important for fleabane.

Germination of fleabane can occur all year round when wet conditions and temperatures of 10-25°C (optimal 20°C) occur. These conditions are more prevalent in autumn and spring, with fleabane often emerging with winter crops or during the winter fallow in the northern regions.

Knowing when new germinations of fleabane occur in an attempt to target control of small plants is critical as it is more effective than on larger plants. As fleabane grows its stem becomes harder and it develops a strong root system. The harder stems and large root system of larger plants enable the plants to regrow more effectively following herbicide applications.

Actively managing fleabane during winter in fallows or in-crop is more effective then summer as emerging seedlings are slower to grow. This slower growth allows more time to apply effective herbicide control options. It is also very important to manage winter germinating fleabane prior to spring as fleabane grows rapidly as the season warms and rainfall increases in northern regions leading into to summer.

While paddock control is critical so is monitoring fencelines and channels as fleabane is wind dispersed, continual replenishment of the seedbank can occur if these areas are ignored.

Crop Competition

Managing fleabane in-crop is a useful tool as fleabane does not establish well in low light conditions. Light conditions can be manipulated by planting crops at higher density and on narrower row spacing. Narrow rows and higher plant populations are primarily used when planting winter crops compared with the wider summer row spacing configurations in the northern region.

Image of fleabane
Due to its small seed size, fleabane will only emerge from the top 1cm of soil.

It is important to monitor crops as fleabane can survive at small growth stages under a competitive crop and be easily overlooked. However, once the crop is removed the fleabane which is present can develop quickly and the opportunity for effective control can be missed without regular monitoring.

Cultivation

Fleabane is a weed that proliferates in no-till farming systems. This is partly because many populations of fleabane present under this system now have a level of resistance to glyphosate but also due to the weed’s ecology. Due to its small seed size, fleabane will only emerge from the top 1cm of soil.

Cultivation to bury seed to a depth deeper than 1cm can be an effective tool to manage fleabane populations. Although this approach can dramatically reduce the number of fleabane which emerge, it also increases the longevity of the seed i.e. seed that is buried will not germinate but it will remain viable for a longer period. Occasional cultivation can be a useful tool for seed bank management but this is not a technique to utilise frequently as it will simply return viable seeds to the soil surface.

Cultivation may also be a viable option for salvage management. Where ‘blow outs’ occur this may be the only economic option to effectively control large flowering plants.

Herbicide strategies

Fleabane management improved dramatically when growers switched from trying to control large plants in summer fallow to targeting small weeds still in the rosette stage during the winter crop phase. There are three key stages where herbicides can be useful to manage fleabane populations; pre-plant, in-crop and post-harvest.

Image of fleabane
There are three key stages where herbicides can be useful to manage fleabane populations; pre-plant, in-crop and post-harvest.

Residual herbicides (fallow and in-crop)

One of the most effective strategies to manage fleabane is the use of residual herbicides in fallow or in-crop. Trials have consistently shown good levels of efficacy from a range of residual herbicides commonly used in sorghum, cotton, chickpeas and winter cereals.

Residual (and knock-down) in fallow:

In Fallow, at least 3 months prior to planting sorghum:FallowBoss® Tordon® (300 g/L 2,4 D + 75 g/L picloram + 7.5 g/L aminopyralid) at 700 mL/ha + atrazine (600 g ai/L) at 3-5 L/ha

Trial work to date has indicated that increasing water volumes from 50-100 L/ha may help the consistency of residual control with application timing to ensure good herbicide/ soil contact also important.

Knock-down herbicides in fallow:

Group I herbicides have been the key products for fallow management of fleabane with 2,4 D amine and picloram/2,4-D products the most consistent herbicides evaluated. Despite glyphosate alone generally giving poor control of fleabane, trial work has consistently shown a benefit from tank mixing glyphosate with 2,4-D and picloram/2,4-D products in the first application.

  • Amicide® Advance (700 g/L 2,4-D) at 0.65-1.1 L/ha + Weedmaster DST (470 g/L glyphosate) at a min of 1.4 L/ha. Follow with a double-knock of Nuquat® (250 g/L paraquat) at 1.6 -2.0 L/ha when weeds are from stem elongation to flowering.
  • FallowBoss Tordon at 700 mL/ha + glyphosate (450 g/L) at 1.6-2.4L/ha (can also be followed 5-7 days later with Spray.Seed® at 1.6 L/ha as a double-knock) - prior to winter cereals or sorghum.
  • Tordon® 75 D (2,4 D + picloram) at 0.7 L/ha + glyphosate
  • Sharpen® (700 g/kg saflufenacil) at 17-34 g/ha + 1% Hasten® spray oil.

Post emergent herbicides in winter cereals:

  • Amicide Advance at 1.5 L/ha
  • FallowBoss Tordon at 300 mL/ha
  • Hotshot® (10 g/L aminopyralid + 140 g/L fluroxypyr) at 750 mL/ha + either metsulfuron (600 g ai/kg) at 5 g/ha or MCPA LVE (600 g ai/L) at 580 mL/ha (refer to label for appropriate growth stages)
  • Lontrel® Advanced (600 g/l clopyralid) at 150 mL/ha
  • Paradigm® (200 g/kg halauxifen Group I + 200 g/kg florasulam Group B) at 25 g/ha + MCPA LVE (600 g ai/L) at 300-600 mL/ha.

Double-knock control

The use of a double-knock strategy is recommended for the control of fleabane in fallow systems as weed size increases and herbicide efficacy generally reduces. The most consistent and effective double-knock control of fleabane has involved including 2,4 D or picloram/2,4-D products + glyphosate in the first application followed by paraquat or Sharpen as the second. Glyphosate alone followed by paraquat will result in high levels of leaf desiccation but plants will generally recover. Trial work conducted by the NGA in the north has shown regrowth observed following the application of Sharpen as the second knock to be more consistent than other group G herbicides or paraquat when applied at the same timing.

Timing of the second application in fleabane is approximately 7-14 days after the first application. However, the interval to the second knock appears quite flexible. Increased efficacy is obtained when fleabane is actively growing or if rosette stages can be targeted. Although complete control can be obtained in some situations, control levels frequently only reached approximately 70-80%, particularly when targeting large flowering fleabane under moisture stressed conditions. The high cost of fallow double-knock approaches, and inconsistency in the control level of large mature plants, is a key reason that proactive fleabane management should be focused at earlier growth stages.

Nitrogen rates, crop rotation and root health are proving to be the biggest factors affecting yield for southern region farmers according to interim results from the GRDC’s National Paddock Survey.

With The Grain: National Survey Providing Widespread Yield-gap Information

Author: Rachael Oxborrow, GRDC 

Date: 7th June, 2018

Nitrogen rates, crop rotation and root health are proving to be the biggest factors affecting yield for southern region farmers according to interim results from the GRDC’s National Paddock Survey.

CSIRO group leader and farming systems scientist Dr Roger Lawes revealed these key yield gap variables at GRDC Research Updates earlier this year. He outlined preliminary results which showed for a given amount of rainfall the most dominant factors affecting yield were nitrogen nutrition and crop health, with weeds proving a lesser factor.

Consultants and researchers from farming systems groups across the country are now preparing for their fourth and final year of data collection for this GRDC investment led by Birchip Cropping Group (BCG) and CSIRO.

Their work will give farmers a region-by-region understanding of what variables they should be most concerned with in bridging the gap between their actual yield and water limited yield. This is defined as the maximum possible yield based on optimal sowing date, current cultivars and nutrients, pests, disease and weeds not limiting yield.

National Paddock Survey project lead and BCG consultant Harm van Rees says final results from the investment will equip farmers with a clear idea of the manageable factors limiting yield in their region based on results from their location.

“This research is trying to take previous yield gap analysis a step further and take it to individual paddocks rather than a soil type,” he says.

“We monitor two zones in each paddock and work out the size of the yield gap for each zone and then analyse the data for factors limiting production over a four year rotation.

“This analysis is only for factors that farmers can manage. For example, if a grower has subsoil limitations on their property with high salt levels then that can’t be changed as it is a physical limitation, but if they’ve got a disease level, then that can be managed.”

In the western, northern and southern GRDC regions across the Australian grain belt, 250 paddocks are being monitored, with 90 locations being monitored in the south. These farms were selected by local consultants and farm groups and represent the range of prevailing rainfall and soil conditions across the grain belt.

Consultants and farming systems groups monitor two zones within each NPS paddock which includes: deep soil cores prior to sowing which is analysed for soil N, soil water content and subsoil limitations. They also record tillage, stubble retention, crop type, cultivar, sowing date and monitor the crop for weeds, insects, diseases and take plant root samples which are analysed for root health. At the end of each season, crop yields are measured using a harvester’s yield monitor. The data collected for each season is reviewed at annual project meetings, to allow consultants and researchers to discuss insights and information regarding individual paddock performance.

Dr Lawes says results so far show the yield gap cannot be attributed to one factor but rather a number of factors as shown in table 1. The level of impact of each factor varies by region and in some cases the factors were driven by the first limiting constraint.

Dr Lawes says the survey has identified the yield gap, or the difference between actual and potential yield in wheat, was 1.1 tonnes per hectare in the northern region, 1.2t/ha in the southern region, and 1.3t/ha in the western region.

Frost and heat shock are yield limitations many farmers would identify as major concerns in the southern region.  Mr van Rees says this is particularly the case as the timing of frost and heat shock events appears to be changing.

“Frost and heat shock are manageable in some ways through cultivar and sowing dates, but they can never be completely avoided,” he says.

“Most farmers are already managing many limiting factors and information from the National Paddock Survey will help them further with recognising their exposure to the most limiting factors and options for management.”

GRDC research code: BWD00025

WA growers who hope to take advantage of early-season moisture now have a new variety option following the release of Australian Grain Technologies’ (AGT) winter wheat Longsword.
Derived from Mace, Longsword is best suited to low and medium rainfall areas.
The new variety can be sown from early April

New early-season wheat variety released

WA growers who hope to take advantage of early-season moisture now have a new variety option following the release of Australian Grain Technologies’ (AGT) winter wheat Longsword.

Derived from Mace, Longsword is best suited to low and medium rainfall areas.

The new variety can be sown from early April, fitting into the planting window between the longer season, traditional winter wheats and the more commonly-sown spring varieties.

AGT wheat breeder Dr James Edwards said the new variety had unique maturing characteristics that made it suitable for planting within a wide and flexible sowing window, while remaining less susceptible to frost and heat damage.

“In environments with a distinct dry finish, if flowering occurs outside of the optimum time or grain fill occurs too slowly, drastic yield reductions can occur,” Dr Edwards said.

“With its three vernalisation genes, Longsword will remain vegetative across a broad planting window and should deliver an optimal flowering time, but not linger through grain fill.

“There is nothing else like it on the market as winter wheat breeding and selection has traditionally been undertaken in areas where there is a softer finish to the season.”

AGT national marketing manager Dan Vater said AGT had been working on Longsword for the past eight years.

He said the winter wheat variety was ideal for WA growers wanting to capitalise on opportunistic earlier sowing.

“Growers are constantly expressing a desire to get into paddocks earlier but we are already pushing the limits on how early we can sow our current spring varieties, Mr Vater said.

“We finally have a variety that you can plant through most of April before you swap over to a spring wheat like Scepter in May.

“It gives them (growers) much more flexibility on when they can start sowing and if there’s some early rains then they might be able to take advantage of them.”

Mr Vater said while Longsword was not expected to replace more popular WA wheat varieties, it could be a useful cropping program option.

 

29 Nov, 2017

STRATEGIC deep tillage was chosen as a tool to ameliorate soil water repellence and subsoil constraints at a trial established by the Mingenew Irwin Group (MIG). MIG research and development manager Debbie Gillam said severe water repellent soils in the region were typically low in water holding capacity and fertility and as a result had limited productivity......

Delving into water repellence

05 Apr, 2017 02:00 AM

Farm Weekly

 

STRATEGIC deep tillage was chosen as a tool to ameliorate soil water repellence and subsoil constraints at a trial established by the Mingenew Irwin Group (MIG).

MIG research and development manager Debbie Gillam said severe water repellent soils in the region were typically low in water holding capacity and fertility and as a result had limited productivity.

"Low productivity means that the amelioration approach needs to be as cost effective as possible," Ms Gillam said.

The trial, which was funded through GRDC's water repellence project, looked at the use of the cost effective one-way disc ploughing.

The plough is a robust tool that is simple to modify for partial soil inversion.

Ms Gillam said the research site compared a one-way disc plough to rotary spading (a proven amelioration option) and to other deep ripping approaches, including some of the newer very deep rippers.

"One of the two key messages to come from the research includes the difficulty of achieving productivity benefits if other constraints such as weeds and compaction remain unaddressed," she said.

"The other is that rotary spading and modified one-way ploughing improved water infiltration, the evenness of soil wetting, weed control and crop yield."

Compaction was identified as an issue at the Mingenew trial site.

Subsoil compaction was severe (2.5MPa) from 22 centimetres and extreme (3.5MPa) from 30cm.

Of the rippers used, the Tilco deep ripper effectively loosened the soil to 54cm, the Terraland ripper to 48cm, the Ausplow ripper to 38cm, the one-way plough to 36cm and the spader to 30cm.

In the untreated control moisture infiltration followed the typical pattern for repellent soils with preferential flow paths and large areas of "dry patch" indicating bypass flow.

Water infiltration was significantly improved by rotary spading and one-way ploughing.

Deep ripping treatments did not improve soil water infiltration and soil water content.

DAFWA research officer Steve Davies helped with the trial and said for many deep sands, deep ripping with topsoil slotting could be one of the most economical ways of overcoming subsoil compaction and acidity (to depths of 40-60cm).

"However, on severely repellent sands it could be that deep ripping is inadequate and may require options that overcome repellence and assist with weed control while at the same time addressing subsoil compaction and acidity," he said.

"Addressing water repellence without also addressing the other subsoil constraints will limit the likely productivity benefits and must be addressed."

Trial work is on-going and MIG will release further findings in 2017.

Mixed farmer David Wolfenden says on-farm trials and his own observations have consistently shown that profitable returns are closely tied to the wellbeing of his land. David, who farms at Rand in southern NSW, became interested in soil health in 1978 when he hosted a New South Wales Department of Primary Industries (DPI) trial investigating minimum tillage........

Soil health checks keep profit potential alive

Date: 16.03.2017

Author: Nicole Baxter

Grain Research & Development Corporation 

Southern NSW grower David Wolfenden shares some of the lessons learned on his decades-long journey to tie improved soil health to income health.

 

 

Mixed farmer David Wolfenden says on-farm trials and his own observations have consistently shown that profitable returns are closely tied to the wellbeing of his land.

David, who farms at Rand in southern NSW, became interested in soil health in 1978 when he hosted a New South Wales Department of Primary Industries (DPI) trial investigating minimum tillage.

He could see the potential for improved soil health so he bought a one-pass seeder and became a founding member of the Southern Farm Management Group, a group of growers interested in trying new farm practices.

Soon after the group was formed the members looked into a system that had benefited irrigated growers.

The system, called Crop Check, encouraged soil and crop-health monitoring to improve returns.

Developed by former NSW DPI agronomist John Lacy, it suggested more than 10 checks were necessary to grow high-yielding wheat.

It was not long before David had implemented a dryland version of the system and was well on the way to improving yields.

“A key lesson was that good yields are a result of getting many factors right, with soil health a major contributor to most of these factors,” David says.

He points out that adopting minimum tillage followed by stubble retention started as an “act of faith” and took a decade to produce measurable benefits – the key indicator being improved profit.

As a consequence, David sees exploiting the benefits of improved soil biology as a long-term pursuit.

“We are only now starting to understand soil biology, and science is offering us the opportunity to open Pandora’s box,” he says.

“This research needs to continue if we want to fully harness the benefits of soil biology and increase our wheat yields to 10 tonnes per hectare.”

 

Water-holding capacity

David’s next step was examining if in-paddock variation of water-holding capacity (WHC) was limiting yield. Electromagnetic surveys were completed and zones mapped.

In 2011, a trial investigated whether targeting nutrients to soil WHC could improve crop returns.

At sowing, monoammonium phosphate was applied across three zones at 5, 10 and 20 kilograms/ha of phosphorus.

Nitrogen was applied at 40kg/ha as urea during early August. The crop’s response was judged visually and at harvest by yield map, and compared with a nil-phosphorus plot.

The results showed a yield response up to 10kg/ha of phosphorus, even though soil tests indicated there was a high level of Colwell phosphorus (38 to 61 milligrams/kg) across the zones.

A gross margin analysis showed the added net income from applying 10kg/ha of phosphorus was $37/ha, resulting in a $2.63 return for every $1 spent.

There was no response to added nitrogen, possibly due to the dry spring and the time of application.

 

Feeding the bugs

Recently, David attended a workshop where CSIRO’s Dr Clive Kirkby discussed the importance of ‘feeding the bugs’ in the soil as a way of increasing crop growth.

His work suggests some freely available sulfur, phosphorus and nitrogen are required for the soil biology to maximise activity and break down stubble into plant-available nutrients.

Over the years, David says soil tests have shown an improvement in most nutrients including phosphorus, sulfur, calcium and magnesium.

Adding lime has lifted soil pH and reduced aluminium toxicity, allowing crops to thrive.
Going forward, he sees the challenges as refining practices across the zones and fully using soil biology activity.

With organic carbon (OC) at 1.8 per cent, he wonders if his farm management will need to change as it moves beyond two per cent.

“On top of minimum tillage and stubble retention, Dr Kirkby’s work may point to ways we can increase the biological activity and further increase OC levels,” David says.

“Studies indicate that yields might plateau when my OC levels reach two per cent, but

I believe research needs to look at whether we need to change our practices to utilise higher levels and maximise the potential of soil biology.”