Assessing seed priming, sowing date, and mulch film to improve the germination and survival of direct‐sown Miscanthus sinensis in the United Kingdom

Abstract

Direct sowing of Miscanthus seed could lower crop establishment costs, and increase the rate of grower uptake and biomass supply for the emerging bio‐economy. A replicated field trial was conducted at two contrasting UK sites: Aberystwyth ( ABR ) in mid‐Wales and Blankney ( BLK ) in Lincolnshire. These sites encompass the west–east meteorological gradient in the United Kingdom where the growing season at ABR is cooler and wetter while BLK is warmer and drier. Primed and unprimed Miscanthus sinensis seeds were sown directly onto the soil surface with and without a clear biodegradable mulch film, at nine dates interspersed from May to October. Average daily mean soil surface temperatures measured over the first 2 months after sowing under the mulch film were higher than control plots (2.7°C ABR and 4.2°C BLK ). At both sites, the film covering also affected soil volumetric moisture relative to uncovered control plots (−3% ABR and 8% BLK ), demonstrating the negative impact of mulch film when sowing on dry soil. Over nine sowings, seed germination at ABR under film varied between −28% and +18% of germination under control conditions. Seedlings from the first three sowings at both sites under film had sufficient physiological maturity to survive the first winter period. At BLK , mulch film significantly increased tiller count and height in both the first and second years after sowing. At ABR , where temperatures were lower, film covering significantly increased tiller height but not count. Water priming had no significant effect on seed viability or germination in the field tests. Base temperatures for germination of primed and unprimed seeds on a thermal gradient plate were 7.0°C and 5.7°C, respectively, with a ± 1.7°C confidence interval. Based on our results for M. sinensis in the United Kingdom, we recommend the sowing of unprimed seed in May under film and only when the soil is moist.

How to Generate Yield in the First Year—A Three-Year Experiment on Miscanthus (Miscanthus × giganteus (Greef et Deuter)) Establishment under Maize (Zea mays L.)

“…The most common procedure, rhizome planting, entails costs of 1904-3375 € [30]. Although future improvements in seed-based establishment could reduce the costs of this method [16,31], it will only be practicable for fertile genotypes. As the most common and commercially available genotype Miscanthus x giganteus is triploid [30], it does not produce fertile seeds.…”

Allelopathic and intraspecific growth competition effects establishment of direct sown Miscanthus

“…Germination in soil within a controlled environment was used to determine the effect of competition using a more realistic substrate but controlling for other potentially confounding factors such as temperature. This experiment used 3 mm sieved and autoclaved soil collected from the field described in Ashman et al (2018; Aberystwyth, Wales, 52°24′53.8″N, 004°02′31.7″W). Four replicate trays (360 × 210 mm) were filled 50 mm deep with a sandy loam soil, then 32 (4 × 8) divots were made (15 mm × 15 mm × 15 mm) in the surface of each replicate tray 30 mm apart.…”

“…Results were averaged within each set of eight divots for each replicate tray. Each tray was covered with SAMCO grey mulch film (Adare, Ireland) as previously described for use in Miscanthus field planting (Ashman et al, 2018). The trays were placed in a line in a Fisons Fitotron 600h 120 plant growth chamber, and kept under constant illumination (from both the tungsten and fluorescent lighting 170 ± 10 µmol m −2 s −1 ; Caffarra, Donnelly, Chuine, and Jones, 2011), at 25°C for 32 days.…”

“…Switchgrass ( Panicum virgatum ) is often oversown (400 seeds per m 2 ) to account for low establishment (Vogel, 1987) and this technique may be suitable to provide a more consistent density of Miscanthus plants from seed. In the United Kingdom, direct sowing of Miscanthus seed was tested by sowing in rows at 300 seeds per meter (Ashman, Awty‐Carroll, Mos, Robson, & Clifton‐Brown, 2018), but this resulted in uneven emergence. A refinement of this method, that better controls plant density, is oversowing seed in small patches of 1 cm diameter (here referred to as clusters).…”

Soil N2O emissions with different reduced tillage methods during the establishment of Miscanthus in temperate grassland

“…However, the impact of no till cultivation on N 2 O emissions can vary and seems to be linked to soil type and water content (Chatskikh & Olesen, ; Grave et al., ; Rochette, ). The use of a bio‐degradable film mulch has shown improved agricultural and economic performance of Miscanthus by increasing shoot density during establishment in cool temperate climates through increased soil temperature and conservation of moisture (Ashman, Awty‐Carroll, Mos, & Robson, ; Olave et al, ). Although not currently routinely employed with Miscanthus , the use of this type of film may expand as an aid in establishment, with increasing use of lower agricultural grade land at higher altitudes (Alexander et al, ; Clifton‐Brown et al, ; Lovett et al, ).…”