Factors Affecting the Viable Seed Content of Soils Beneath Lowland Pastures

SUMMARY (2) Freshly-shed seeds of the four species above were tested for innate dormancy. The effects of light and of burial of seed were also studied. Many of the seeds of P. annua shed early in the season were innately dormant. Burial and darkness enforced dormancy on a proportion of the P. annua and P. trivialis seeds. Seeds of F. rubra and L. perenne had no innate dormancy, nor was dormancy enforced by burial or darkness. (3) The results of the assessments of buried viable seed content are interpreted in the context of the history of the swards and the management practices applied. The presence or absence of dormancy mechanisms, together with the amount of seed produced and the chances of this seed being buried, are discussed in relation to the buried viable seed data. All the results are related to the known sequence of changes in sward botanical