Minnipa SA trials

To assess the role of annual medics as a break crop in a wheat-sheep mixed farming system, by measuring the biomass produced over the growing season followed by the retention of the pasture residue over the summer autumn period, then subsequently assessing the impact of the pasture in the following cereal phase in terms of yield and grain quality.

To assess the performance of annual medics in a pasture – wheat rotation over the 2009 and 2010 seasons.

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.

To include the Minnipa flock within the program to help:

• educate ram buyers of the merits of ASBVs so they seek out, and buy rams from, breeders that are members of Sheep Genetics “LAMPLAN” or “MERINOSELECT”.
• encourage more breeders to become members of Sheep Genetics “LAMPLAN” or “MERINOSELECT” and to offer ASBVs on sale rams.
• encourage more breeders to use ASBVs when buying stud sires or semen.

To build resilience into EP farms by understanding the interactions between soil potential, climate and management.

To compare current released varieties at two locations on Eyre Peninsula, plus a demonstration at Penong.

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.

To investigate swathing early then harvesting for weed seed collection to evaluate usefulness for farmers in providing 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.

To discuss the critical growth stages for maintaining sound nutrition of crops on Upper EP.

• To assess the crop production and economic outcomes from applying P at nil, replacement, 10 kg P/ha (district practice, DP) and 20 kg P/ha (double district practice, DDP) rates on 2 soil types at Minnipa.

To monitor crop production and economic outcomes from applying P at nil, replacement, average and twice average rates on both a deep sandy loam and a shallow constrained soil.

To compare current released varieties at two locations on Eyre Peninsula.

Previous work in the Mallee has shown the EM38 technology has benefited farm profit. On that basis we have commenced a demonstration on the Minnipa Agricultural Centre to validate previous Mallee outcomes.

• To investigate the potential to incorporate a mixture of perennial species into farming systems in low-rainfall areas across southern Australia.

To identify better perennial species than what is already available in low rainfall areas.

To measure comparative wheat yields in response to varying P applications on 2 soil types.

• To identify alternative perennial legumes to lucerne suitable for incorporation within cropping systems, there are at least 3 options potentially adapted to areas within the Eyre Peninsula environment.

To identify alternative perennial legumes to lucerne suitable for incorporation within cropping systems, there are possibly at least 3 options adapted to areas within the Eyre Peninsula environment.

To reinvigorate the livestock component of the EP farming system.

To report on a series of articles are from trials undertaken in 2011 on the three focus sites or funded via the
EPFS 3 project.

To assist farmers to understand what their land is capable of producing under a range of conditions and how to tailor inputs to get the most profitable outcomes.

• The Minnipa Agricultural Centre (MAC) has been funded by Grains Research and Development Corporation (GRDC) to run a research and extension program (Eyre Peninsula Farming Systems 3 – Responsive Farming Systems) to improve water use efficiency on farms by 10% on upper Eyre Peninsula (EP). This is seen as one of the main ways to improve profit and manage risk for farm businesses.

To provide data to assist in decision making when planning to use a field crop as a potential resource for grazing, hay and/or grain based on seasonal conditions, while in some cases utilising the benefits of a break crop within the cropping rotation.

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 understand the impact of soil carbon and nitrogen cycling on disease suppression.

To understand the impact of soil carbon and nitrogen cycling on disease suppression.

To see if disease suppression can be stimulated by increasing organic matter (i.e. carbon) inputs into farming systems under local conditions.

To investigate the question 'Is time of sowing as important in a high decile season'?

• To measure crop response in a field trial at Minnipa to different fertiliser rates over time, with soil P levels measured annually as Colwell P.

To assess the P response from current and residual fertiliser applications.

To assess the P response from current fertiliser applications at MAC.

To compare the impact of four different management strategies on production, profitability and sustainability at the Minnipa
Agricultural Centre.

The Farming Systems Competition was commenced in 2000 to compare the impact of four different management strategies on production, profitability and sustainability at the Minnipa Agricultural Centre.

• To compare the impact of four different management strategies on production, profitability and sustainability at the Minnipa Agricultural Centre.

To test whether nitrogen management options typical for upper EP would ‘switch off’ disease suppression.

To compare up front applications of N with a split application of N, as well as the efficiency of foliar N compared to granular N.

To question how much nutrition did you export to the silo last year and how much fertiliser are you applying this year?

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 determine the optimum ratio of peas and canola for grain yield, profitability and post harvest ground cover.

To further evaluate variable rate sowing as a tool to improve profitability in low rainfall upper EP farming systems, this broad acre trial
began in 2008 and has continued through to 2010.

To manage risk through variable rate technology using different inputs over variable soil types and testing the use of Yield Prophet to match plant available water and nutrition with modelling of climatic conditions, knowing that we can have unpredictable finishes to seasons.

• To compare very early maturing feed and malting barley lines selected from the University of Adelaide Barley Program advanced yield trials.
• To compare these varieties with other adapted and current varieties, and to evaluate their specific adaptation to the upper EP environment.

To provide early feed for stock in autumn, a time of year when pastures haven’t established properly, and get ewes and lambs out of the confinement feedlot and onto good quality feed as soon as possible.

To see how the commonly grown varieties with a range of maturities respond to seasonal conditions, soil type and sowing time, i.e. to evaluate how they can best fit into the farming system.

To investigate the effects of row direction, row spacing and stubble cover on grain yield and quality.

To investigate the effects of row direction, row spacing and stubble cover on grain yield and quality.

To evaluate variable rate technology using low, standard and high seed and fertiliser inputs on 3 soils zoned as of poor, medium and good production potential from a pre-2008 yield monitor, EM38 and elevation maps.

To demonstrate the impact of different stubble management techniques on soil biota activity and nutrition demands would be monitored using the same fertiliser applications in crop and by comparing yields. In subsequent years the effect of different treatments will be monitored.

To trial supplementing sheep grazing medics with La Trobe pellets to accelerate growth.