Cotton Emergence Force as Affected by Soil Temperature, Moisture, and Compression
- Y. N. Chu,
- C. G. Coble and
- W. R. Jordan *
Emergence force of a seedling is a major factor influencing the ability of the seedling to emerge through a surface soil crust. This study was conducted to evaluate effects of soil physical conditions on the maximum emergence force of cotton [Gossypium hirsutum L.]. Effects of soil temperature and moisture on the emergence force were studied when the seedling was supported laterally to prevent buckling. The effect of compression of the top soil was investigated using a plate on the soil surface to simulate a crust. Measured emergence forces when the seedlings were laterally supported were greater than previously reported for cotton. Maximum emergence force varied quadratically with increases in soil temperature and moisture. The highest force was 11.4 N for a temperature of 28.5 °C and a soil water potential of −10 J kg−1. Maximum emergence force increased linearly with the hypocotyl cross-sectional area, while calculated turgor potentials of hypocotyl cells were 768, 756, and 518 J kg−1 at soil water potentials of −10, −30, and −300 J kg−1, respectively. The emergence force was greatly reduced when lateral support was not provided. A compression pressure of 13.8 kPa on the top soil increased emergence force from 0.9 N at zero compression to 2.2 N, only ≈20% of the maximum force observed with adequate lateral support.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © . .