Assessing the Contribution of Citrus Orchards in Climate Change Mitigation through Carbon Sequestration in Sargodha District, Pakistan

Agroforestry olive orchards for soil organic carbon storage: Case of Saiss, Morocco

Soil supports numerous ecosystem services and contributes to climate change mitigation. Several publications have appeared in recent years considering soil as a persistent carbon sink and reported that agroforestry systems have a potential for soil organic carbon storage. However, there is still little knowledge about the soil organic carbon storage in olive orchards and its role in climate change mitigation. Therefore, soil samples collected from topsoil (0-30 cm) and subsoil (30-60 cm) in 57 different olive orchards provide an excellent opportunity to investigate the role of several factors (tree ages, planting density, farming system type and soil depth) in driving soil organic carbon storage variability in agroforestry olive orchards compared to olive trees in monoculture system across the Saiss region (Morocco). The difference was significant between the two types of plantation systems studied (agroforestry and monoculture) and between the two soil layers studied (topsoil and subsoil). Agroforestry olive orchard systems stored approximately 1.2 times the organic carbon in the soil compared to monoculture systems. In addition, topsoil stores 1.5 times compared to subsoil. The correlation results showed a positive relationship between the organic carbon stock of the topsoil and the subsoil, indicating that an increase in the topsoil is accompanied by an increase in the organic carbon stock of the subsoil. These results can provide a better understanding of the effect of agroforestry on deep soil organic carbon stock in Moroccan olive orchards. Furthermore, it can provide a valuable reference for future research on the soil organic carbon storage variability in Morocco and from an international perspective.

Health Risk and Metal Contamination Assessment in Orange (Citrus aurantium) of Pakistan: a Multivariate Study

Toxic metals (TMs) are serious health hazard and are known to accumulate in fruits, which are consumed by people, owning to their distinct sweet flavor and potential health benefits. In the present study, arsenic (As), lead (Pb), chromium (Cr), copper (Cu), cadmium (Cd), nickel (Ni), and mercury (Hg) were measured by atomic absorption spectrometry (AAS) techniques in orange samples from 11 farmhouses of Sargodha, Pakistan. Principal component analysis (PCA) is a very useful analysis and data-reducing tool. This technique was used to explore the relationship between different metal levels in the oranges. The conventional wet acid digestion method was validated and assured with two (02) certified reference materials NIST-SRM 1515-Apple and (CRM) NIST-1570a Spinach Leaves by recovery test coupled with standard addition procedure. The results showed that Cd and Cr average daily intakes are 0.084 and 0.15 mg slightly higher than World Health Organization/Food and Agriculture Organization of the United Nations (WHO/FAO) recommended tolerable daily intake respectively. The assessment of health risk was also carried out in form of total hazard quotient (THQ) and hazard index (HI), indicating three heavy metals (Pb, Cd, and Cr) have significant human health risk potential to consumers while Cu, As, Hg, and Ni have non-significant (THQ < 1) health risks.