Assessing the Impact of Organic Farming Practices on the Soil Organic Carbon Stock and the Efflux of Greenhouse Gases of Calcareous Arid Soils

Soil is a significant part of the global terrestrial carbon and nitrogen biogeochemical cycles. Recently those cycles have been intensively altered by anthropogenic activities. That leads to a massive imbalance that enriches the atmosphere with additional Greenhouse gases (GHG). Organic farming practices are considered a form of sustainability that can enhance soil quality and reduce GHG emissions. Little research has focused on the impact of crop rotation and compost addition in the enhancement of organic carbon soil (SOC) and reducing GHG emissions from the soil on arid lands. Thus, this research aimed to investigate the impact of annual crop rotation (Sweet corn, Sunflower, and Eggplant) and unique alkaline compost addition on improving (SOC) stock and reducing GHG emissions in arid soils. This research was conducted on a field scale for two years. Unique alkaline compost was used as a treatment with two different application doses (dose1 and dose2) based on soil exchangeable primary macronutrient calculation with an equivalent dose of NPK for both application doses. The closed static chamber method was used to measure the CO₂, CH₄, and N₂O efflux from the plots. Randomized complete block design (RCBD) experimental design was followed. Soil samples were collected at the beginning and the end of each growing season from each plot to measure the change in soil organic matter and SOC. The primary results of this study showed there was a significant increase of SOC from sweetcorn to eggplant season in both compost application doses. SOC stock in the second application dose at eggplant season was the highest among all the other treatments in all growing seasons. Similarly, organic matter (O.M) content increased steadily from sweetcorn to eggplant seasons. Regarding the GHG effluxes, dose1 of the compost contributes to lower N₂O and CH₄ efflux compared to dose2 in all the growing seasons. Dose 2 of the compost in sweet corn season contributed to the highest CH₄ and N₂O effluxes. The primary results from this research confirmed that utilizing organic farming practices can enhance the organic carbon stock in arid land and lower GHG emissions from the soil.