TEMPERATURE PROFILES IN A RAPE FIELD BEFORE AND AFTER HARVEST

Abstract

Temperature was recorded at replicate locations in a rape field, both in the soil and in the crop canopy. Sources of variability in these records are examined, and the temperatures are compared with standard records from nearby meteorological stations. Variability within replicates depends on elevation, reaching a maximum at a soil depth of 5 cm. Temperatures in the soil of the rape field were more extreme than those recorded under sod at a nearby meteorological station, though the differences were small when a full rape canopy was present. Removal of the canopy at harvest caused wide diurnal fluctuations and an increase in the average daily maximum at all crop elevations, though temperatures recorded at a nearby meteorological station were similar before and after harvest. Linear regression equations are provided that estimate daily maximum and minimum temperatures in the soil of the rape field to a depth of 20 cm from standard meteorological records.