Effect of different agricultural practices on carbon emission and carbon stock in organic and conventional olive systems

Abstract

Agricultural practices, particularly land use, inputs and soil management, have a significant impact on the carbon cycle. Good management of agricultural practices may reduce carbon emissions and increase soil carbon sequestration. In this context, organic agricultural practices may have a positive role in mitigating environmental burden. Organic olive cultivation is increasing globally, particularly in Italy, which is ranked first worldwide for both organic olive production and cultivated area. The aim of the present study was to assess the effects of agricultural practices in organic and conventional olive systems on global warming potential (GWP) from a life cycle perspective and to identify the hot spots in each system. The impacts assessed were associated with the efficiency of both systems at sequestering soil in order to calculate the net carbon flux. There was a higher environmental impact on GWP in the organic system because of higher global greenhouse gas (GHG) emissions resulting from manure fertilisation rather than the synthetic foliar fertilisers used in the conventional system. However, manure was the main reason behind the higher soil organic carbon (SOC) content and soil carbon sequestration in the organic system. Fertilisation activity was the main contributor to carbon emissions, accounting for approximately 80% of total emissions in the organic system and 45% in the conventional system. Conversely, given the similarity of other factors (land use, residues management, soil cover) that may affect soil carbon content, manure was the primary contributor to increased SOC in the organic system, resulting in a higher efficiency of carbon sequestration in the soil following the addition of soil organic matter. The contribution of the manure to increased SOC compensated for the higher carbon emission from the organic system, resulting in higher negative net carbon flux in the organic versus the conventional system (-1.7 vs -0.52tCha-1 year-1, respectively) and higher efficiency of CO2 mitigation in the organic system

Spatial-Temporal Characteristics of the Driving Factors of Agricultural Carbon Emissions: Empirical Evidence from Fujian, China

“…The residual sum of squares (RSS) and F-value of GTWR were also better than those of the other models. Moreover, the smaller the AIC value is, the higher the precision of the model is [58]. Furthermore, if the difference of the AIC values between two models is more than three, this shows that there is a significant difference between the two models.…”

“…R & D investment in technology can significantly reduce agricultural carbon emissions, so the governments should continue to increase R & D investment in technology in the agricultural field and develop new technologies that are low carbon and have higher efficiency. Moreover, the governments should also promote new production models, i.e., organic agriculture and ecological agriculture, and finally, give full play to the role of agricultural technology in low-carbon agriculture [58]. In addition, there is a time lag effect of R & D investment on agricultural carbon emissions.…”

Soil carbon stock in olive groves agroforestry systems under different management and soil characteristics

“…Few studies are available examining the C stock in olive groves in Italy, notwithstanding the diffusion of these systems in the Mediterranean region. Mohamad et al (2016), who examined C stock in organic and conventional olive cultivation systems, report 63.69 ± 9.94 Mg C ha -1 SOC in the organically managed olive grove and 54.58 ± 1.16 Mg C ha -1 in the conventional one.…”

Environmental Impact Assessment of Organic vs. Integrated Olive-Oil Systems in Mediterranean Context

“…Looking at the calculated CO 2 fluxes (Annual Net Primary Productivity versus total emissions), this olive orchard system showed a positive budget, with a high gain of CO 2 (15.45 t ha −1 year −1 ) sequestered from the atmosphere. Mohamad et al [51] found that manure was the primary contributor to increased SOC in an organic system, resulting in a higher efficiency of carbon sequestration. This SOC increase compensated for the higher carbon emission from the organic system, resulting in higher negative net carbon flux in the organic versus the conventional system (−1.7 vs. −0.52 t C ha −1 year −1 , respectively) and higher efficiency of CO 2 mitigation in the organic system.…”