Dynamics of wet and dry aggregate stability from a three-year microalgal soil conditioning experiment in the field

Palmelloid, unicellular green microalgae in the genus Chlamydomonas were inoculated onto replicated plots at rates calculated to approximate feasibility through sprinklers (5 x 10 super(11) log phase cells ha super(-1) yr super(-1)) and with an airplane (5 x 10 super(7) ha super(-1) yr super(-1)) to test their value as soil-conditioning agents. Applications were made to the same parcels of a Quincy loamy sand for three consecutive growing seasons. High-rate plots consistently showed significantly greater (5% level) stability to slaking of 0.92- to 1.68-mm sized aggregates from the surface (2 to 3 mm) algal veneer compared with low-rate and control plots, which were not different. This ranged from about 11 to 27% increased stability at the end of each season.