SARDI Minnipa Agricultural Centre trials

To identify the severity of K deficiency in broad-acre crops in respect to the Colwell K level in the top 10 cm of soil.

To identify the severity of K deficiency in broad-acre crops in respect to the Colwell K level in the top 10 cm of soil.

To identify the severity of K deficiency in broad-acre crops in respect to the Colwell K level in the top 10 cm of soil.

To identify the severity of K deficiency in broad-acre crops in respect to the Colwell K level in the top 10 cm of soil.

Investigate strategies for correcting K deficiency in broad-acre crops.

To identify the severity of K deficiency in broad-acre crops in respect to the Colwell K level in the top 10 cm of soil.

To identify the severity of K deficiency in broad-acre crops in respect to the Colwell K level in the top 10 cm of soil.

To identify the severity of K deficiency in broad-acre crops in respect to the Colwell K level in the top 10 cm of soil.

To identify the severity of K deficiency in broad-acre crops in respect to the Colwell K level in the top 10 cm of soil.

To identify the severity of K deficiency in broad-acre crops in respect to the Colwell K level in the top 10 cm of soil.

Failure to control annual weed species that persist through cropping phases facilitates replenishment/establishment of weed seedbanks. Consequently, this maintains weed interference in subsequent years of crop production. Harvest weed seed control (HWSC) has been widely adopted in Australia since its inception over three decades ago to prevent redistribution of weed seeds across cropping fields during commercial harvesting operations (Walsh et al. 2017). Implementation of HWSC obstructs fresh seedbank inputs by subjecting the weed seed bearing chaff fraction to a treatment, such as combustion (narrow windrow burning), mechanical pulverisation (impact mills), decomposition (chaff-lining) and removal (chaff cart). Chaff-lining has been readily adopted by growers because of the low cost of modifying a harvester to confine the chaff fraction into a narrow row between stubble, or onto dedicated wheel tracks in controlled traffic farming systems (chaff-tramlining). There is a paucity of literature examining seedbank decline of important Australian weed species in chaff-lines, however a common conjecture is that a mulching effect is created by a combination of physical and chemical influences (Walsh et al. 2018). Field observations suggest that in the absence of seed decay, control failures of annual weed species and volunteer crop plants may be exacerbated. Therefore, growers urgently need information that substantiates the implications of chaff-lining to weed seedbanks.

This research aims to determine in which situations extra fertilisation can bring benefits to growers in 14 different Eyre Peninsula (EP) environments.

Every season, growers need to make choices over limited resources in order to optimise their profitability. Soil type and water represent two of the key limiting resources which define the grain yield potential of a paddock. The unpredictability of growing season rainfall patterns restricts in-season fertiliser applications for EP growers, due to the associated high economic risks. As a risk management strategy, growers often apply lower rates of nutrients than required to achieve the water limiting yield potential (Sadras and Roget 2004, Monjardino et al. 2013). Therefore, less than optimum nutrient rates are applied in many instances, and maximum grain yield gains are not reached on occasions where opportunities have existed. Understanding soil water and nutrient dynamics can be useful to determine when in-season extra fertiliser applications are worth the investment in EP dryland farming systems.

This study used a subset of the Eyre Peninsula Agricultural Research Foundation (EPARF) soil moisture probe network locations to benchmark the water limited yield potential and determine the achievable grain yield of cereals crops across major soil types of EP.

Farming systems in the low rainfall zone of southern Australia are dominated by cereal production. There is increasing concern about grass weed and soil-borne disease pressure, diminishing soil fertility (particularly nitrogen), and water use efficiency, as a result of continuously cropping cereals. Break crops have a key role to play in addressing these issues, as well as diversifying crop production and economic risk, and maintaining long-term sustainability of the system. However, there remains a lack of information available to growers about choosing the break crop best suited to their situation, as break crop development to date has largely occurred in medium and high rainfall zones. The aim of this research is to identify the best break crop options for different climate, soil type and biotic stress situations within major cropping regions of the southern low rainfall zone.

Soil testing for N, P, K and S is a key strategy for monitoring soil fertility of cropping soils as well as for refining fertiliser application strategies for future crops. For this to be successful, the relationship between the soil test and likely response to applied nutrients needs to be well calibrated. Many of these calibrations were developed from fertiliser trials conducted over 20 years ago and have provided robust guidelines on many soil types, but mostly for cereals. Since these trials were conducted cropping systems have changed significantly and altered the face of soil fertility in the Australian grains industry. A detailed re-examination of those existing guidelines is needed to ensure they are still relevant in current farming systems.

As part of the GRDC funded MPCN2 (More Profit from Crop Nutrition) program, a review of data in the Better Fertilizer Decisions for Cropping (BFDC) database showed gaps exist for key crops, soils and regions. Most of these gaps relate to crops that are (i) new to cropping regions or are a low proportion of cropped area, i.e. break crops, (ii) emerging nutrient constraints that had previously been adequate in specific soil types and (iii) issues associated with changing nutrient profile distribution. This project (UQ00082) is closing gaps in the BFDC database using replicated trials. Trials have been established on sites selected for nutrient responses and run over multiple years to develop soil test-crop response relationships. By using wheat as a benchmark alongside a break crop, we should be able to extend the relevance of the guidelines beyond the conditions at the trial site.

Barley grass continues to be a major grass weed in cereal cropping regions on the upper Eyre Peninsula (EP). Swathing a cereal crop involves cutting and collecting the cereal crop and weeds into windrows at 20 to 40% grain moisture and allowing it to dry. Having the weed seeds cut and in the windrow before the seed heads shatter and before tillers fall over (lodging), may allow greater weed seed collection when using a chaff cart or windrows. Swathing early then harvesting for weed seed collection needs further evaluation as it may provide farmers with another tool for integrated weed management, especially for barley grass that matures and sheds seed before crops ripen.

On the upper Eyre Peninsula (UEP), highly calcareous soils constitute a high proportion (more than 1 million hectares) of soils used for agricultural production (Bertrand et al. 2000, Bertrand et al. 2003). The website ‘Yield Gap Australia’ (http://yieldgapaustralia.com.au/maps/) identifies that the average grain yield on Western Eyre Peninsula (WEP) and UEP is between 41 and 45% of the water limited yield potential (1.5 t/ha for WEP and 1.8 t/ha for UEP). Closing the grain yield gap for wheat on UEP presents a challenge to growers, particularly on highly calcareous soils where nutrient deficiencies are common (Holloway et al. 2001). The production of insoluble minerals through the interaction of soil calcium carbonate with soluble nutrients such as phosphorous and trace elements (Holloway et al. 2001), combined with low soil moisture conditions prevents these nutrients from being readily available to the plant (Lombi et al. 2004). Holloway et al. (1999-2003) demonstrated the possibility of providing phosphorus (P) to the plant in an available form by applying fluid P fertilisers instead of granular fertilisers at seeding.

The majority of landholders in Australia, including the western and upper Eyre Peninsula currently use granular fertilisers which require good soil moisture conditions to enable uptake of nutrients by crops. Growers and advisors have noted that highly calcareous top soils dry out quickly after rainfall events, which may contribute to poor water use and nutrient extraction efficiency, and may also be a reason why diseases such as Rhizoctonia solani have greater impact in these soils. In addition, as a risk management strategy, growers often apply lower rates of nutrients than required to achieve the water limiting yield potential (Sadras and Roget 2004, Monjardino et al. 2013). A better understanding of soil moisture, root disease and factors which influence nutrient availability and the efficacy of fertilisers are needed to increase the water limited yield potential of the highly calcareous soils (McLaughlin et al. 2013).

Field trials were conducted in 2019 to investigate these factors on the nutrition of wheat on highly calcareous soils.

Barley grass possesses several biological traits that make it difficult for growers to manage it in the low rainfall zone, so it is not surprising that it is becoming more prevalent in field crops in SA and WA. A survey by Llewellyn et al. (2015) showed that barley grass has now made its way into the top 10 weeds of Australian cropping in terms of area infested, crop yield loss and revenue loss.

The biological traits that make barley grass difficult for growers to manage in low rainfall zones include:

• early onset of seed production, which reduces effectiveness of crop-topping or spray-topping in pastures,
• shedding seeds well before crop harvest, reducing harvest weed seed control effectiveness compared to weeds such as ryegrass which has a much higher seed retention,
• increased seed dormancy, reducing weed control from knockdown herbicides due to delayed emergence, and
• increasing herbicide resistance, especially to Group A herbicides, used to control grass weeds in pasture phase and legume crops.

Barley grass management is likely to be more challenging in the low rainfall zone because the growing seasons tend to be more variable in terms of rainfall, which can affect the performance of the pre-emergence herbicides. Furthermore, many growers in these areas tend to have lower budgets for management tactics, and break crops are generally perceived as more risky than cereals. Therefore, wheat and barley tend to be the dominant crops in the low rainfall zone. This project is undertaking coordinated research with farming systems groups across the Southern and Western cropping regions to demonstrate tactics that can be reliably used to improve the management of barley grass.

Part 1: Medic cultivars were grown in soil with high boron levels in a glasshouse, leaf damage symptoms recorded and cultivars allocated to different tolerance groups (Howie 2012). 

Part 2: The above identified that all spineless burr medic cultivars are susceptible to high boron levels. Screening wild accessions (supplied by the Australian Pasture Genebank) identified a burr medic accession with boron tolerance and vigorous growth. The boron tolerant accession was crossed with current spineless burr medic cultivars Scimitar and Cavalier. F2 plants with high early vigour were selected and a molecular marker used to identify homozygous boron tolerant plants. A single seed descent breeding method using speed breeding was used to obtain uniform lines. Lines were seed increased at Waite in 2018 and lines with the highest agronomic performance selected for 2019 field evaluation trials. A cohort of 16 boron tolerant lines along with their  parents and barrel medic cultivars that differ in boron tolerance, were sown at Roseworthy and Minnipa. The trials were managed as best practice first year annual medics to maximise dry matter and seed production. Best practice consists of a high sowing rate (10 kg/ha), controlling broadleaf and grass weeds, monitoring and controlling insects and no grazing. Dry matter production was  assessed and pods collected. Seed yield will be determined by April 2020.

In southern Australian mixed farming systems, there are many opportunities for pasture improvement. The Dryland Legume Pasture Systems (DLPS) project aims to boost profit and reduce risk in medium and low rainfall areas by developing pasture legumes that benefit animal and crop production systems. A component of the DLPS project aims to quantify the impacts of different pasture
legume species on livestock production and health. Included are widely grown legumes (strand medics and vetch) and legumes
with reasonable prospects of commercialisation (trigonella).
A five-year grazing system trial was established at the Minnipa Agricultural Centre (MAC) in 2018. It is the main livestock field site
for the DLPS program in southern Australia.

Legume pastures have been pivotal to sustainable agricultural development in southern Australia. They provide highly nutritious feed for livestock, act as a disease break for many cereal root pathogens, and improve fertility through nitrogen (N) fixation. Despite these benefits pasture renovation rates remain low and there is opportunity to improve the quality of the pasture base on many low to medium rainfall mixed farms across southern Australia. A diverse range of pasture legume cultivars are currently available to growers and new material is being developed. Some of these legumes, such as the annual medics, are well adapted to alkaline soils and have high levels of hard seed, which allow them to self-regenerate from soil seed reserves after cropping (ley farming system). Other legume cultivars and species are available and being developed that offer improved seed harvestability, are claimed to be better suited to establishment when dry sown and/or provide better nutrition for livestock. Regional evaluation is needed to determine if they are productive and able to persist in drier areas (<400 mm annual rainfall) and on Mallee soil types common to the mixed farming zone of southern Australia.

The Dryland Legume Pasture Systems project will both develop and evaluate a range of pasture legumes together with innovative establishment techniques, measure their downstream benefits to animal and crop production and promote their adoption on mixed farms.

This trial was established in 2018 to assess a diverse range of annual pasture legumes in order to determine whether there are more productive and persistent options for the drier areas (< 400 mm) of the mixed farming zone of southern Australia. In 2019 the trial was allowed to regenerate to determine which legumes regenerated and how their performance differed from the establishment year.

The Dryland Legume Pasture Systems project will both develop and evaluate a range of pasture legumes together with innovative establishment techniques, measure their downstream benefits to animal and crop production and promote their adoption on mixed farms.

There are reports of low grain protein levels in wheat following medic pastures and many observations of poor medic nodulation. Previous work has shown that rhizobial inoculation can improve the nodulation of medics in the SA and Victorian Mallee, and that more generally about 50% of the populations of medic rhizobia in soils are suboptimal in their nitrogen (N) fixation
capacity. This trial aimed to:
• Determine if inoculation can improve medic nodulation at Minnipa,
• Quantify the amount of N fixed by different legumes, and
• Assess impacts on the following wheat crop.

Legume pastures have been pivotal to sustainable agricultural development in southern Australia. They provide highly nutritious feed for livestock, act as a disease break for many cereal root pathogens, improve fertility through nitrogen (N) fixation and mixed farming reduces economic risk. Despite these benefits, pasture renovation rates remain low and there is opportunity to improve the quality of the pasture base on many low to medium rainfall mixed farms across southern Australia. A diverse range of pasture legume cultivars are currently available to growers and new material is being developed. Some of these legumes, such as the annual medics, are well adapted to alkaline soils and have high levels of hard seed, which allow them to self-regenerate from
soil seed reserves after cropping (ley farming system). Other legume cultivars and species are available and being developed that
offer improved seed harvestability, are claimed to be better suited to establishment when dry sown and/or provide better nutrition for
livestock. Regional evaluation is being undertaken to determine if they are productive and able to persist in drier areas (<400 mm
annual rainfall) and on Mallee soil types common to the mixed farming zone of southern Australia.

Change in sowing time can have multiple effects on crop-weed competition. Delayed sowing can provide opportunities to kill greater proportion of weed seedbank before seeding the crop, but weeds that establish in late sown crops can be more competitive on a per plant basis. This is one of reasons why farmers who have adopted early seeding have reported excellent results in crop yield and weed suppression.  Therefore, it is important to investigate sowing time in combination with other practices across different rainfall zones. The review of Widderick et al. (2015) also recommended research on sowing time in many crops.  Delayed sowing can also reduce crop yield so the gains made in weed control may be completely nullified by the yield penalty.

There has been some research already on crop seed rate on weed suppression but none of these studies have investigated the benefits of higher crop density in factorial combinations with sowing time and herbicide treatments. Crop seed rate is an easy tactic for the growers to adopt provided they are convinced of its benefits to weed management and profitability.  Furthermore, growers in the low rainfall areas tend to be reluctant to increase their seed rate due to concerns about the negative impact of high seed rate on grain screenings.

This field trial at Minnipa was undertaken to investigate factorial combinations of sowing time, seed rate and herbicides on the management of annual ryegrass in barley.

To make full use of in-crop rainfall, stored soil moisture and nutrients, and prevent weed seed contamination, the control of weeds in a pulse break crop phase is essential. Currently, herbicides are the primary method of weed control in broadacre cropping systems. However, there are limited options for broadleaf weed control in pulse crops, as there are few effective broadleaf post emergent herbicides available for use in faba bean and lentil. Along with limited control options, the presence of possible herbicide residues, such as sulfonylureas (SU), from previous crops are major deterrents for including pulses in a cropping rotation where there is an increased risk of herbicide damage. In recent years, Group B herbicide tolerant (HT) lentil and faba bean varieties have been released to Australian growers and have proven very popular for giving more flexible weed control options, particularly for late emerging broadleaf weeds. The Group B herbicide tolerance traits not only provide growers with in-crop options for broadleaf weed control, but also allow these pulse crops to be grown on Group B (including SU) herbicide residues, which can persist from previous crop applications for up to 24 months or longer, depending on rainfall (minimum of 700 mm) and soil pH (as per DuPont^™ Glean^® and Tackle^® WG product labels).

The aim of these trials was to evaluate the levels of tolerance to simulated residues and post-emergent applications of Group B herbicides in lentil XT varieties, and a faba bean mutant derived line with Group B herbicide tolerance traits.

With larger seeding programs, increased summer weed control to conserve soil moisture and more variable autumn rainfall patterns, more growers Australia-wide are moving toward dry sowing.

On upper Eyre Peninsula in 2017 and 2018, seed was placed in the soil for many weeks with limited soil moisture, some seed still germinated but the delayed plant emergence often resulted in a lower plant establishment. This raised questions by growers about the soil factors which reduce germination and establishment.

This article summarises a pot trial which assessed the impact of DAP placement on wheat establishment on three different soil types; a red loam (Minnipa Agricultural Centre (MAC)) and two grey calcareous soils (Streaky Bay and Cungena).

With larger seeding programs, increased summer weed control to conserve soil moisture and more variable autumn rainfall patterns, many growers Australia wide are continuing to dry-sow. More traditionally, growers may have previously ‘dabbled a little’ in dry-sowing and are observing with interest the successes and failures of dry-sowing systems.

On upper Eyre Peninsula in 2017 and 2018, seed was placed in the soil for many weeks with limited soil moisture; some seed still germinated but the delayed plant emergence often resulted in a lower plant establishment. This raised questions by EP farmers and consultants about the soil factors which influence seed germination and establishment.

Research trials were established in 2019 to assess the impact of management on seed germination and establishment on three different soil types in field trials and pot experiments; a red loam [Minnipa Agricultural Centre (MAC)] and two grey calcareous soils (Cungena and Streaky Bay) for:

• Impact of fertiliser type (P and N) and fertiliser placement,
• Impact of practices, herbicides and seed dressings.

This article reports on field trials undertaken in 2019 at three sites.

Pulses are growing in popularity as a result of good prices and rotational benefits such as decreased N input and enhanced grass weed control options. However frost and combinations of water and heat stress at critical growth stages can compromise crop yield. Previous work in pulses has established that the most important time to maintain growth and limit stress is the period around pod set. Sowing date and variety choice are the two main tools to manipulate time of flowering and pod-set, and thus manage the risk of extreme temperatures, water stress and the trade-off between frost and heat risk.

This research aims to identify the safer temperature windows for the critical period for yield for faba bean and lentil in cropping regions of southern Australia. This work follows on from EPFS Summary 2016 p62, EPFS Summary 2017, p146 and EPFS Summary 2018, p62.

Crop intensive farming systems are running down soil carbon, requiring increased inputs to maintain or increase yield without necessarily improving profitability. Mixed species cover cropping offers a new approach to reverse this trend in the Australian context. It is a key component of some farming systems overseas but is yet to be adopted widely in southern Australia. In the context of this project, mixed species cover crops refers to a diverse mix of plant species grown together but often outside the main growing season to build fertile and resilient soils.

Potential benefits of cover crops include improving soil organic carbon, structure and health, while decreasing weed and disease levels for following crops, but these must be balanced against the cost of growing the cover crop and the water and nutrients it will use. Many potential cover crop options exist and while growers are beginning to investigate these, local guidelines are yet to be developed to inform decisions.

A trial at Minnipa is investigating mixed species cover crops grown over winter. The principle behind growing a mixture of species rather than a monoculture is that it mimics naturally occurring diverse ecosystems. Different root systems host different microorganisms, fungi and soil biota that improve the dynamic properties of soil leading to healthier soil that has higher infiltration rates for water and are better able to retain that moisture. This retained water can potentially be used for the following cereal crops. Different root systems also inhabit different parts of the soil profile and therefore access water and nutrients more completely, so no single section is severely depleted. Organic matter is distributed more evenly throughout the soil profile and more carbon is available to soil organisms. The qualities of two or more different species may also improve the overall productivity. Legumes fix nitrogen that can be used by other plants. Tall plants provide shade for emerging seedlings, reducing their exposure to water and temperature stress. Climbing plants such as peas will often use the taller plants as a trellis. The fibrous root systems of many cereals and grasses bind the soil to protect it from wind erosion, particularly under dry conditions. Brassicas can function as biofumigants, suppressing soil pests, especially root pathogens and plant-parasitic nematodes. Leaving residue on the soil surface lowers the soil temperature, reducing soil water loss through evaporation and providing protection from erosion. A diverse cover crop also offers a more balanced diet to livestock.

Barley grass continues to be a major grass weed in cereal cropping regions on upper Eyre Peninsula (EP). The use of unmanned aerial vehicle (UAV) technology to identify and assess barley grass populations in paddocks and monitor potential resistant populations may be a useful tool for farmers. This approach was tested in three paddocks on upper EP Minnipa Agricultural Centre (MAC), Minnipa Hill and Yaninee using a UAV during the 2017, 2018 and 2019 growing seasons at three different timings, with paddock transects conducted to verify grass weed density in paddocks. In 2019 grass weed escape paddocks were targeted at MAC and Condada in the final flights.

The aim of the research was to determine if the UAV imagery could monitor the grass weed populations across seasons in crops and pastures, if resistant weed patches were continually in the same area of the paddock and if the information could be useful for farmers to adopt this method to better target grass weed control.

This research was done to develop predictive formulas that can be used by growers to estimate in-season soil nutrients from soil samples taken at different depths and crop nutrient content from proximal sensing (PS) data.

The upper Eyre Peninsula (UEP) is a challenging environment for growers, due to the irregular rainfall patterns which are coupled with lower soil fertility. Additionally, calcareous soils with poor structure and low water holding capacity provide additional restrictions for plant growth, as growers currently use granular fertilisers which require good soil moisture conditions to enable the uptake of nutrients. Topsoils from calcareous soils may dry quickly after rain events, which may explain poor water use and nutrient extraction efficiency.

PS technologies have the potential to support grower’s nutrient management decisions by monitoring in-season soil and crop water and nutrient content (Allen et al. 2017, Arsego et al. 2017). PS uses a wide range of wavelengths to predict soil and crop nutritional status in a non-destructive, quick, and inexpensive way. PS technology is mostly limited to laboratory use. The development of small, portable PS devices may allow the use of this technology in farm paddocks in the near future. In this study, we combined different UEP trials to develop predictive models for PS for crop nitrogen, crop nutrient content and soil moisture.

Russian Wheat Aphid (RWA) was first reported in 2016 in South Australia (SA), and has since been detected widely throughout Victoria, and in New South Wales (NSW) as far north as Coonamble and as far east as Tamworth.  It has not been detected in Queensland or Western Australia.

As part of the GRDC investment “Russian Wheat Aphid Risk Assessment and Regional Thresholds”, field trials were run at Minnipa for the second year through the Minnipa Agricultural Centre team. The purpose of these trials was to look into the level of natural infestation of cereal crops, and the effect of high RWA populations (obtained through artificial inoculation) on aphid and symptom dynamics and yield loss. This trial was one of a suite of trials undertaken in SA, Victoria, Tasmania, and NSW over 2018 and 2019, and contributes to a larger dataset.

The aim of the trial reported here was to determine the risk of RWA infestation in cereal crops in the Minnipa area in 2019 and observe the effect of high aphid numbers achieved through artificial inoculation on crop development and yield.

Barley grass is now one of the top 10 weeds of Australian cropping in terms of area infested, crop yield loss and revenue loss (Llewellyn et al. 2016). Barley grass has several biological traits that make it difficult for growers to manage it in the low rainfall zone, so it is not surprising that it is becoming more prevalent in field crops in SA and WA.

Through recent GRDC investment, the research project ‘Demonstrating and validating the implementation of integrated weed management strategies to control barley grass in the low rainfall zone farming systems’ (hereby referred to as GRDC Low Rainfall Barley Grass) has commenced. An initial grower survey of current practice and attitudes towards barley grass was undertaken in 2019 to be used as the baseline to assess changes in grower attitudes and any change in practices after the completion of the three-year project.

The effect of combinations of crop row spacing, seedbed utilisation and preemergence herbicides on ryegrass management in barley

Farmers in the Kimba area have been producing oaten hay for export for several years. The industry has been expanding, with dedicated storage facilities established in recent years on the outskirts of Kimba. To maximise production and quality, the Buckleboo Farm Improvement Group wanted to identify the best current oaten hay variety for the Kimba area.

To:

• determine if physical intervention and soil mixing improved grain yield on a sandy soil on eastern EP,
• compare deep ripping with inclusion plates to spading,
• determine if deeper ripping improved results, and
• identify if the addition of fertilisers or organic material (OM) provide additional benefits.

To identify the best break crop options for different climate, soil type and biotic stress situations within major cropping regions of the southern low rainfall zone.

Legume pastures have been pivotal to sustainable agricultural development in southern Australia. They provide highly nutritious feed for livestock, act as a disease break for many cereal root pathogens, and improve soil fertility through nitrogen (N) fixation. Despite these benefits, pasture renovation rates remain low and there are opportunities to improve the pasture base on many low to medium rainfall mixed farms across southern Australia. There are also reports of poor protein levels in wheat following medic pastures and many reports of poor medic nodulation. Previous work has shown that substantial responses to inoculation are possible in the Victorian Mallee, which is possibly linked to the poor N fixation capacity of some populations of soil rhizobia. The extent to which inoculation can still improve medic nodulation on Eyre Peninsula requires clarification.

The Dryland Legume Pasture Systems (DLPS) project aims to develop recently discovered pasture legumes together with innovative management techniques that benefit animal and crop production and promote their adoption on mixed farms in the low and medium rainfall areas of WA, SA, Vic and southern NSW.  One objective within this work program is to increase the amount of fixed N provided by the pasture.

This is a component of a new five year Rural Research and Development for Profit funded project supported by GRDC, MLA and AWI; and involving Murdoch University, CSIRO, SARDI, Department of Primary Industries and Regional Development; Charles Sturt University and grower groups.

Legume pastures have been pivotal to sustainable agricultural development in southern Australia. They provide highly nutritious feed for livestock, act as a disease break for many cereal root pathogens, and improve fertility through nitrogen (N) fixation. Despite these benefits pasture renovation rates remain low and there is opportunity to improve the quality of the pasture base on many low to medium rainfall mixed farms across southern Australia. A diverse range of pasture legume cultivars are currently available to growers and new material is being developed. Some of these legumes, such as the annual medics, are well adapted to alkaline soils and have high levels of hard seed, which allow them to self-regenerate from soil seed reserves after cropping (ley farming system). Other legume cultivars and species are available and being developed that offer improved seed harvestability, are claimed to be better suited to establishment when dry sown and/or provide better nutrition for livestock. Regional evaluation is needed to determine if they are productive and able to persist in drier areas (<400 mm annual rainfall) and on Mallee soil types common to the mixed farming zone of southern Australia.

The Dryland Legume Pasture Systems project will both develop and evaluate a range of pasture legumes together with innovative establishment techniques, measure their downstream benefits to animal and crop production and promote their adoption on mixed farms.

In southern Australian mixed farming systems, there are many opportunities for pasture improvement, providing positive impacts to both cropping and livestock systems. Dryland legume pastures are necessary in low to medium rainfall zones to support productive and healthy livestock, along with optimal production in crops following these pastures. The majority of pasture species used in these mixed farming systems are short-lived annuals that complete their lifecycle from winter to early summer, with dry seasonal conditions resulting in a shorter growth window between germination and senescence. This is a major issue for livestock producers in these regions due to unreliable rainfall patterns leading to fluctuating legume growth, and the subsequent impact on feed supply and quality for grazing animals.

Innovative and improved legume species and pasture systems have the potential to fill existing nutrient gaps, thus reducing supplementary feed required for optimum ruminant performance, and maintain or improve livestock productivity through growth rates, fertility or product quality.

The Dryland Legume Pasture Systems (DLPS) project aims to boost profit and reduce risk in medium and low rainfall areas by developing recently discovered pasture legumes together with innovative management techniques that benefit animal and crop production and farm logistics. A theme of the DLPS project involves ‘Quantifying the benefits of novel legume pastures to livestock production systems’ and aims to maximise the advantages that pastures provide to livestock through increased animal growth and reproduction by extending the period of quality feed and reduced supplementary feeding. The animal systems research within the project will also assess areas of understanding anti-nutritional factors and ‘duty of care’ for new pasture species, providing opportunities for improved weed management and evaluate the main benefits of novel self-regenerating pasture legumes in crop rotations on animal production, health and welfare.

This theme is a component of a five year Rural R&D for Profit funded project supported by GRDC, MLA and AWI; and involving Murdoch University, CSIRO, SARDI, Department of Primary Industries and Regional Development; Charles Sturt University and grower groups.

A five-year grazing system trial was established at the Minnipa Agricultural Centre (MAC) in 2018 to examine this theme and is the main livestock field site for the DLPS trial in the southern region of Australia.

To determine the impact of different fertiliser products and placement relative to the seed on crop emergence, crop WUE and grain yield.

To report on a summary of paddock surveys of harvest weed seed collection samples taken in 2016, 2017 and 2018 as a part of the GRDC Stubble Initiative project ‘Maintaining profitability in retained stubbles on upper Eyre Peninsula’ (EPF00001).

To determine the potential toxicity of the fungicide P-Pickel T (PPT) to rhizobia applied as a commercial inoculant (peat and freeze-dried) on field pea (R. leguminosarum, group F) in field conditions in a soil with a low rhizobial background.

To investigate water repellence mitigation options at seeding. The trial aims to identify the driving chemistries (surfactants vs humectants) and application techniques (furrow surface, vs seed zone) that are better able to lift crop responses under local sowing conditions. This article reports on the Year 1 data, with more work being planned for the 2019-20 seasons.

To identify crop safety levels and economic risk of pre- and post-emergent herbicide use on lentil across different soil types and environments in the southern low rainfall zone. This project builds on previous GRDC-funded projects, including DAV00113 (southern region pulse agronomy).

To identify plant varieties or mixtures that can increase dry matter production of the pasture break phase on the highly alkaline soils of upper Eyre Peninsula. Current cropping and grazing systems are mostly based on monocultures and the potential feed base of the break phase could be broadened to be more productive for grazing and available for a longer time period in the season. Current oat varieties, mixed break crops and newer pasture species were trialled at Piednippie in 2018 to investigate whether a more productive and prolonged feed base is possible.

Barley grass weed density was monitored in three paddocks on upper EP (Minnipa Agricultural Centre (MAC), Heddle’s at Minnipa and Wilkins’ at Yaninee using an UAV during the 2017 (EPFS Summary 2017, p 83) and 2018 growing seasons at three different timings, with paddock transects conducted to verify grass weed density in paddocks.

To determine whether adding extra nitrogen (N) at GS31 will bring benefits above the current standard practice of only applying nitrogen at or near sowing in three different Eyre Peninsula (EP) environments.

To assess a range of commercial rhizobia inoculant products, application strategies and sowing times to provide growers with recommendations that ensures adequate nodulation and nitrogen fixation in dry sown crops.

To develop predictive formulas that can be used by growers to estimate in-season soil moisture at different depths and crop nutrient content from proximal sensing (PS) data.

To assess barley grass weed seed capture by swathing and weed seed capture in chaff dumps after harvest, to determine how effective these practices can be in contributing towards an IWM program for barley grass on upper Eyre Peninsula.