EFFECT OF SOIL TEMPERATURE ON SEEDLING EMERGENCE

Abstract

Rate and percentage of emergence of 19 native and cultivated herbaceous species were studied at the following soil temperature: 6°, 13°, 18°, and 24 °C. The soil temperatures were held uniformly constant, and emergence data at the end of 5 weeks from four replications in time were obtained. The rate of emergence of all species was greater at 18 °C. than at 6 °C., and of all but five species was greater at 24 °C. than at 18 °C.The percentage of emergence of barley, bromegrass, crested wheatgrass, mustard, oats, peas, spring wheat, and wild oats was not significantly affected by soil temperature. Beans, corn, sugar beets, and sunflowers showed significantly lower emergence percentages at 6 °C. than at the three higher soil temperatures. Alfalfa, creeping red fescue, winter wheat, orchardgrass, rough fescue, sweet clover, and flax emerged best at moderate soil temperatures.