Influence of cultivation regime upon buried weed seeds in arable cropping systems.
The effects of cultivation on the number of seeds of different spp. in arable land were investigated at 4 sites over several yr. Soil cores were obtained from uncultivated and ploughed plots and the seed content determined by germinating the seeds and counting and identifying the emerged seedlings. Distribution of seeds was not uniform in the soil profile and fluctuated annually on ploughed plots. Seed decline, although not markedly different between treatments, was more rapid in ploughed soil. The rate of seed decline at different depths was similar for both uncultivated and ploughed plots. Successful germination alone could not account for the rate of seed decline reported, indicating that losses from other causes were substantial. A considerable number of spp. was recorded in the seed bank (23-30), but the majority was comprised of only a few (3-4).