Fates of weed seeds in soil: a seeded core method of study.
A method is described for the study of the fates of unprotected seeds in soil. Its key features include: (1) selection of seeds on the basis of anticipated high viability; (2) placement of unprotected seeds in known positions in the soil; (3) extraction of soil cores containing the seeds several times each year; (4) elutriation of these cores and recovery of the seeds; and (5) germination and viability testing of the recovered seeds. Initial results for an experiment conducted (start = Nov. 1992) with seeds of four weed species (sunflower, Hibiscus trionum, Rumex crispus and sorghum) in an agricultural field in the midwestern USA (Lincoln) are used to demonstrate the soundness of the method. The strengths, weaknesses and assumptions of the method are discussed.