Buried viable propagules in native prairie and adjacent agricultural sites in central Saskatchewan

Abstract

Soil cores to a depth of 10 cm taken from native prairie and three adjacent agricultural sites were tested for the presence of buried viable propagules by stimulating germination from the samples in the laboratory. A total of 739 individuals per square metre emerged from the native prairie samples with 476 individuals per square metre from the grazed pasture, 520 individuals per square metre from the wheat stubble, and 1667 individuals per square metre from the summer fallow site. In addition, vegetative regeneration, mostly for grasses and sedges, was important in the native prairie and grazed pasture sites, giving rise to 694 and 2154 individuals per square metre, respectively. Nongerminating seeds were recovered at rates, per square metre, of 19 for native prairie, 387 for grazed pasture, 685 for wheat stubble, and 1007 for summer fallow. It is concluded that various cultural and chemical practices have altered the natural buried propagule complement of the region with the populations of weed seeds building up in the soil as cultivation continues.