Prediction of soil temperature from air temperature for estimating corn emergence

• Published in: Canadian journal of plant science 1990-07, Vol.70 (3), p.619-628
• Main Authors: Dwyer, L.M, Hayhoe, H.N, Culley, J.L.B
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; air temperature; Biological and medical sciences; cultivars; Economic plant physiology; Embryo development. Germination; field tests; Fundamental and applied biological sciences. Psychology; Germination and dormancy; growing degree day; Growth and development; growth rate; mathematical models; Plant physiology and development; prediction; seedling emergence; soil temperature; Zea mays
• ISSN: 0008-4220; 1918-1833
• DOI: 10.4141/cjps90-078

The soil thermal environment is critical to corn (Zea mays L.) emergence in short-season production areas. A field study was therefore carried out during the emergence period to test a method to predict 0.05-m soil temperatures from air temperatures and to develop a method to quantify emergence rates as a function of actual and predicted soil thermal units. Thermal units (base 10 °C) were calculated from hourly air and measured and predicted 0.05-m soil temperatures; these thermal units were fit to test emergence data collected on six cultivars. The nonlinear response of percentage emergence to thermal units was approximated by an exponential function. Comparisons of cultivar emergence rates, expressed as the number of thermal units to 0 and 75% emergence, statistically differentiated (P ≤ 0.05) the test cultivars into three main groupings. When predicted soil temperatures were used to calculate the number of thermal units, the thermal units to specific emergence levels were within the equivalent of 1 or 2 d of those generated using measured soil temperatures.Key words: Growing degree days, regression, thermal regimes, seed zone temperature, corn emergence