Developing extruded seed pellets to overcome soil hydrophobicity and seedling emergence barriers

Globally soil water repellency is a major constraint to plant establishment, restricting water infiltration and moisture retention in the seed zone, resulting in poor germination and seedling emergence.

To address this problem within an ecosystem restoration context, we investigated the use of a surfactant in extruded seed pellets to improve native plant recruitment in water repellent topsoils of two proteaceous woodland species, Banksia menziesii R.Br (glasshouse trial) and Lambertia inermis R.Br (field trial). In this two-part study, we first examined B. menziesii seedling performance in detail under glasshouse conditions for differences in survival between the extruded pelleting formulations after an induced drought at 12 weeks.

We demonstrated that there was no difference in seedling emergence, amongst control seed and pellet treatments in B. menziesii. Initially B. menziesii seedlings emerged faster in the control treatment (non-pelleted control seeds) and had greater initial...