Abstract
The angle of repose and internal friction angle of fertilizer seldom correspond. The author studied the relations of these two kinds of angles theoretically. The former angle is affected partly by the latter, but chiefly and proportionally by the aggregation of particles which include cohesion.
The aggregation of fertilizer is a function of a unit-weight, and is affected by internal friction and relative surface area, which is decided by the fineness and shade of a particle or an aggregate. Both theoretically and experimentally, the more intensive the aggregation is, the lower its fluidity is. So that, the angle of repose conveniently indicates the fluidity of fertilizer. The fluidity is, however, affected not only by such negative factors as aggregation which is presumed from the angle of repose, but also by positive factors concerning the reduction of density of fertilizer in case of being sheared.
