Cost of raising soil organic carbon for a quarter-century in a semi arid turkish plain: Harran Plain

Abstract

For decades, scientists have been studying the role of soil organic carbon (SOC) in the environment. SOC in agricultural lands may rise if conditions such as adequate soil water retention, balanced nutrition, minimal tillage, crop rotation, added organic residues, and fertilizers are met. However, implementing all of these measures takes a long time, large expenditures, and enormous effort, particularly in semi-arid and arid lands where organic matter accumulation is difficult; such depletion can be attributed to oxidizing soil conditions. As a result, the long-term cost of increasing organic carbon is uncharted territory for policymakers and land users. In this context, the Harran Plain of SE Turkey, which borders the arid lands of Northern Syria, provides an opportunity to calculate the cost of a unit increase in organic carbon as a result of a drastic change in cultivation over 30 years of irrigation. We attempted to reveal the price of organic carbon increase in a semi-arid region that is far from sustainable agricultural practices after irrigation in this study. The organic carbon in the plain increased by 14,93 t. C/ha i.e. 0.28% on average which is well-below COP 21 initiative of 0.4% annual increase. When the irrigation network investment expenses, annual fertilizer use, and labor need for agricultural production were calculated for the entire Harran Plain from 1995 to 2018, it was calculated that one-ton C/ha in the Harran Plain costs US$491,19. We can estimate that the total SOC increase over 167.400 ha cost around $1,047,029,777. This revealed that increasing SOC in semi-arid climates is an expensive goal.