HERBAGE DRY MATTER PRODUCTION: THE BALANCE BETWEEN GROWTH AND DEATH

Abstract

Dry matter accumulation patterns in pastures are the net result of two processes: the growth of new herbage and the death, and disappearance of old herbage. The relative importance of these two processes in influencing regrowth is discussed and illustrated with data from two markedly different pasture types. In a Nui ryegrass/ white clover pasture and a pure Maku lotus sward, defoliation intensity and season markedly influence the accumulation of dead material, its subsequent disappearance, and hence net dry matter production. The effect of new growth on dry matter accumulation was greatly diminished by within-canopy dry matter losses. The implications of herbage death and disappearance are discussed with reference to the adequacy of certain experimental techniques in estimating herbage dry matter production.