The short-term effects of fresh kelp (Macrocystis integrifolia) on physical properties of a fine-textured soil

In a two year field investigation fresh kelp (M. integrifolia) was broadcast and incorporated into plots of silty clay loam soil in the lower Fraser Valley of British Columbia. The effects of this amendment on bulk density, particle density, total porosity and aeration (volume of pores occupied by air after a saturated core was allowed to freely drain for 12 h at a soil water potential of −0.60 m) were measured. Soil aeration was increased in the first year with 30 and 60 t ha^-1 kelp application but decreased with the 120 t ha^-1 application. This soil aeration effect did not persist into the second year. Soil bulk density, particle density and total porosity were not significantly affected.