Soil CO2 Emission under Different Tillage Practices in Major Soils of Kerala

Abstract

International responsibility is increasing in India to adopt a more pro-active role in greenhouse gas emission. Hence, it is important to develop a clear understanding of our emission inventory towards reducing Carbon dioxide (CO2) emissions. Soils are an important pool of active carbon and tillage can lead to carbon emission from agricultural soils. This study assess the quantity of CO2 release from three major soils (red loam, coastal sandy and paddy field soil) of Kerala under different tillage practices(conventional, with cultivator and with rotovator) and to optimize the tillage practices with minimum CO2 emission. The CO2emission from soil surfaces was measured using base trap method with Sodium hydroxide (NaOH) as base. The influence of soil temperature, soil moisture content, organic matter in soil, soil pH, bulk density, atmospheric temperature and relative humidity on CO2 emission was assessed. The conventional tillage resulted in the maximum CO2 emission followed by the tillage with cultivator and the least value was observed when tilled with rotovator. The maximum CO2 emission was observed in the paddy field soil followed by red loam and the least value was observed from the coastal sandy. The major quantity of CO2 was released just after the breakage of soil in all kind of tillage methods and became almost equal to the undisturbed condition after two hours of ploughing. The bulk density of soil was negatively correlated, organic carbon content was positively correlated, soil temperature was positively correlated and atmospheric temperature was positively correlated with CO2 emission from the red loam soil in all the tillage practices. No significant correlation was obtained between relative humidity and soil moisture with CO2emission.Tillage with rotovator contributed the minimum CO2 to atmosphere and significantly affects the concentration of CO2in the atmosphere, ultimately contribute in mitigation of global warming.