Spatial variability of fathen seeds in the soil under repeat maize cropping

摘要

Variability in distribution of fathen seeds in the soil was investigated to develop sampling protocols. Vertical distribution of seeds was assessed at 0-2.5, 2.5--5. 0, 5.0-10.0 and 10.0-15.0 cm depth. Horizontal distribution of seeds in the top 5cm of soil was assessed in a 20 by 2.5 m grid at 50 cm iontervals. Seeds were extracted from the samples by sieving and their viability was assessed. The fathen seed numbers halved with each 5 cm increase in depth. Seed numbers declined along the row in some cases but there was little localised clumping (+- 1 m ) of the seed. The most efficient method of sampling the fathen seedbank in a large field would be to take samples on a rectangular grid pattern to a depth of 10 cm.