Sown Annuals for Biomass Production

TreatmentsA replicated trial site was established at Navan, near Tarlee, in the Mid North of South Australia. Plots of a range of species were sown using a cone seeder at an appropriate sowing time given the break to the season. Seeding rates were to achieve recommended or commonly used plant populations. There were three times of seeding: TOS 1 June 6, 2011 when all winter growing annuals were planted, TOS 2 November 1, 2011 and TOS 3 November 4 2011 when summer growing annuals were planted. The trial consisted of three replicates and contained 28 ‘winter’ species and 14 ‘summer’ species or varieties. Dry matter production was assessed at critical times during the growing season and total dry matter production measured for each ‘winter’ treatment when the first flowers were withering for legumes, when anthers were protruding for cereals and before grain colour formation in brassicas. For ‘summer’ species a single dry matter assessment was conducted in late autumn 2012. Winter annuals were sown into good moisture conditions. Summer annuals were sown into fallow conditions created by maintaining weed control during winter and although initial conditions for germination were not ideal on Nov 1 heavy rolling immediately after sowing on the Nov 4 seeding created ideal conditions for germination. Summer crops were sprayed for helicoverpa and baited for mice.The soil type chosen for this trial was able to store substantial quantities of soil water from winter rainfall and had no barriers to root proliferation in the top 1 metre of soil. In actual fact it is the ideal soil

type for storing water from rainfall for subsequent use.

ResultsThe dry matter yields of the sown cereals ranged from 5.9 to 11.2 t/ha. The early season production of Moby barley was the highest of all entries. The total production of Endeavour triticale and Southern Green Ryecorn was the greatest. Wheat selected for early vigour (UA47) due to rapid leaf area development produced more dry matter than the dual purpose winter wheat, Naparoo. Pasture legumes produced poor early and winter growth but some made significant growth during spring. The highest pasture legume dry matter was achieved with the Zulu 2 arrowleaf clover. Production of Foxtail Restharrow, Melilotus elegans and hedysarum flexuosum in spring was reasonable. Sub clover is grown widely throughout the mid north but the production of Antas was poor in this trial.The summer growing species had good yields with the exception of the summer legumes. There was no significant difference in the yields of the forage sorghum varieties, one grain sorghum and one maize. White French Millet was significantly lower yielding than the forage sorghum and maize. The millet showed moisture stress much earlier and more significantly than any other species.Of the summer legumes the lab lab and soybean produced worthwhile production while the pigeon pea and cowpea production was very low. Summer growing species may be viable where the soil has a high Plant Available Water Capacity and high Plant Available Water at seeding. This trial was conducted on some of the deepest, well structured soils of the mid north.

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Key Outcomes Sown cereals produced the highest dry matter of winter sown annual species There are a range of annuals that are not currently being used that could have a

role in farm production Annual pasture legumes only produced significant growth in spring The yield of summer species indicates they can be productive on high soil moisture

holding soils that actually contain high amounts of plant available water

Trial Objectives: The aim of the project is to compare a range of sown annual species for biomass production. The biomass production could be utilised for grazing, fodder conservation or energy. Plot Size: 10m x 1.6mReplicates: 3

Trial Results

Table 1 Dry matter production of winter growing annuals

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LSD (P=0.05) 1876

Table 2 Dry matter production of summer growing annuals

Summer Growing Species

Dry Matter kg/ha

Sprint Forage Sorghum 9896

BettaGraze Forage Sorghum 9374Rocket BMR Forage Sorghum 10298Speed Feed 2 Forage Sorghum 8651PAC2434 Grain Sorghum 744584G22 Grain Sorghum 881938F70 Maize 888736Y84 Maize 7664White French Millet 3551Pigeon Pea 987A6785 Soybean 1444Rongai Lab Lab 1047Highworth Lab Lab 829Red Caloona Cowpea NALSD (P=0.05) 1876

Putting It Into PracticeEarly season (July) dry matter production was greatest in sown cereals with Moby barley being the highest. July/August production was greatest with sown cereals and the cruciferous species but the vetch was reasonable. Peas and narbon beans did not produce as much dry matter as vetch and the ryegrasses starting to accumulate dry matter during the early tillering phase. Possible contributing factors – Short periods of waterlogging occurred during winter and may have limited production of very sensitive winter growing species. The LSD is high due to large variability caused by soil type variation.The soil type and Plant Available Water for summer production were near field capacity at sowing.

Acknowledgements Pat and Mary Connell for allowing the MNHRZ

group trials on their land

SARDI for supplying seed of some species

Seed companies for supplying seed

Funding BodyGrain & Graze 2 – A GRDC & Caring for Our Country initiative

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Winter Growing SpeciesDM

(kg/ha)Endeavour Triticale 11190.0Southern Green Ryecorn 10845.5Kohl Rabi 8718.2Winterstar 2 Ryegrass 8506.7Commander Barley 8428.4Hyola 50 Canola 7870.4Moby Barley 7862.0Tetrone Ryegrass 7702.5 Wintaroo Oats 7687.4Tuckerbox Triticale 6985.5Naparoo Wheat 6768.8Zulu 2 Arrowleaf Clover 6072.7Jeanne Ryegrass 6031.3Eurabbie Oats 5959.1Foxtail Restharrow 5941.4UA 47 Wheat 5896.6Sungrazer Ryegrass 5832.7Melilotus elegans 5316.6Garden Radish 5056.7Hedysarum flexuosum 5008.2Morava Vetch 4936.1Blaza Crimson Clover 4579.6Elite 2 Berseem Clover 3833.7Turnip (tops + bottoms) 3799.8Morgan Peas 3784.6Narbon Beans 3139.2Antas Sub Clover 2492.4Spring Onion 488.5LSD (P=0.05) 2605.7

Weather Probe

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