John Olamofe, Prairie View A&M University

Soil CO2 emissions from an experimental research farm: Effects of organic amendments, rain and temperature

Abstract: Vegetated land surface plays an important role in determining the fate of carbon in the global carbon cycle.  However, our understanding of the functioning of the terrestrial biosphere on this scale is subject to considerable uncertainty, especially with respect to the impacts of climatic variables. Soil acts as source and sink for CO2 emission and helps in soil carbon sequestration. The agricultural management practices such as cover cropping and crop rotation influence soil water dynamics as well as carbon cycling by changing soil CO2 emission and uptake rates. The rate of change of soil CO2 emission can be different for different crops and different organic amendments. Thirty-six plots were developed to grow Collard Greens in three rows on Prairie View A&M University’s (PVAMU) research farm. Three types of organic amendments (chicken manure, dairy manure, and Milogranite) were applied to the plots. Each organic amendment was applied to nine randomly selected plots at three different rates (168, 336 and 672 kg/ha). Three random plots were used as control in each row. We measured daily soil CO2 flux for the first two weeks and every other day in a week during the experiment. We evaluated the effects of organic amendments on soil CO2 emission for collard green before and after the rainfall event, and under dry and wet soil conditions. The results showed that the higher the application rates of each organic amendment, the higher the CO2 emissions from the soil. The results also showed higher CO2 emissions under the wet soil conditions than the dry soil. In sum, the project delineates temporal and spatial variations of soil CO2 emission during the growth periods of collard green using different organic amendments and its application rates.

Presentation Author(s):
John Olamofe*, Ram Ray, Richard Griffin, Eric Risch, Ripendra Awal,  Almoutaz Elhassan, Peter Ampim, Ali Fares

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