Influence of simulated seed rain on the seed bank of wild-proso millet

Abstract

A field experiment was conducted between 1988 and 1993 to determine the number of wild-proso millet seed that could be returned to the soil without increasing future soil seed bank populations. The first seed bank (1988) was 15,300 seed m−2 and ranged from 14,000 to 21,000 seed m−2, which represented a high seed population for the area. Seed rain treatments of 0, 3, 6, 12, 24, and 48% of the 1988 soil seed bank were returned each fall. By 1993, more than 90% of the original millet seed bank had been depleted for all treatments. It was estimated that 77% of the seed rain and 68% of the spring seed bank were lost each year. As a result, wild-proso millet must produce approximately three times the seed in the soil to maintain a constant seed bank population.