A particle delivery system of an agricultural row unit includes a particle belt having a particle acceleration section. The particle belt is configured to receive a particle, to accelerate the particle at the particle acceleration section, and to expel the particle toward a trench in soil. The particle delivery system includes a first hub assembly engaged with the particle belt at a first location and a second hub assembly engaged with the particle belt at a second location. The particle acceleration section is disposed generally at the first location, a substantially no-slip condition exists between the first hub assembly and the particle belt at the first location and between the second hub assembly and the particle belt at the second location, and the first hub assembly and the second hub assembly are configured to stretch the particle belt at the particle acceleration section to accelerate the particle.