Evaluation of Soil Heat Transfer in Relation to Climate Variability across Umudike, Abia State, Nigeria

The need to understand the trends, magnitudes, nature and rates of soil quality changes due to soil heat transfer and climate variability is important.Therefore, a study was conducted in Umudike, Ikwuano Local government area of Abia State to evaluate the relationship between soil heat transfer and climatic variables (temperature, relative humidity, sunshine duration, wind speed, rainfall and soil moisture content).From the study area, within an arable land, field measurements of soil temperatures at 0-20cm and 20-40cm depths were taken three times in a day.Soil core samples for moisture content were also collected at 0-20cm depth from the designated sampling points.Daily meteorological data used for this study were obtained from the National Oceanic and Atmospheric Administration/National Centre for Environmental Prediction (NOAA/ NCEP) under the National Weather Service, United States of America.The data were transformed subjected to regression analysis which was used to compare the influence of climate variables on the measured soil heat transfer over a period of time.The results showed that the soil temperature had a strong direct relationship with atmospheric temperature (R 2 = 0.9626), and a weak inverse relationship with rainfall (R 2 = 0.2445), relative humidity (R 2 = 0.1713) and soil moisture content (R 2 = 0.2161).The study showed that the soil thermal conductivity had a weak direct relationship with atmospheric temperature (R 2 = 0.1356), and strong direct relationship with rainfall (R 2 = 0.6833), relative humidity (R 2 = 0.8713) and soil moisture content (R 2 = 0.8931).The relationship between soil heat flux and other climatic variables studied also showed that the soil heat flux had a weak relationship with atmospheric temperature (R 2 = 0.0076), and strong direct relationship with rainfall (R 2 = 0.6396), relative humidity (R 2 = 0.6705) and soil moisture content (R 2 = 0.7309).Furthermore, the effects of climate on soil heat transfer should be studied for different crops to predict the temperature requirements of crops.