The effects of soil organic matter on seedling emergence in sunflower (Helianthus annuus L.)

Seedling emergence is one of the most important factors in the establishment of optimum plant density for a maximum yield. Seed quality and seedbed conditions affect seedling emergence. Seedbed condition is affected by soil content, especially soil organic matter. Therefore, the objective of this study was to determine the effects of soil organic matter on germination and seedling emergence of three hybrid sunflower (Helianthus annuus L.) cultivars. This research was conducted in 2000 and 2001 in field and glasshouse conditions. Perlite and 20 soils with different organic matter contents were used as seedbed conditions. Soil organic matter, environment, and soil organic matter x environment factors had significant effects on seedling emergence. Decreasing soil organic matter content resulted in a decrease of seedling emergence due to the decreases in water content of the soil. This effect was clearer in adverse environmental conditions, especially in the soils with less than 2% organic matter.