ABSTRACT
Soil organic carbon (SOC) is a very important component of the global carbon cycle, and the fate of SOC will have an important impact on the future global climate. Moreover healthy soils are not only more productive from an agricultural point of view, but they also provide other key ecosystem services. Maintaining a healthy level of SOC is essential to maintain or improve soil health and is explicitly mentioned in Global environmental facility strategy documents. Two thousand five hundred ninety surface soil samples from the entire 232257 ha. area which covers fifteen soil series of Nagapattinam district, Tamilnadu, India were analyzed to know the strength and mapping of soil organic pool. The standard procedure was used for the analysis. This study showed that Kutthalam taluk soils ranged between 0.20 and 0.26% with an average value of 0.23%, Mayiladuthurai taluk soil: min 0.14% max 0.49% with the mean value of 0.29%, Kilvelur taluk soils: min 0.29% max 0.57% mean value of 0.39%, Vedaranyam taluk: ranged between 0.21 and 0.37% with an average value of 0.28%, Nagapattinam taluk: ranged from 0.16% to 0.49% mean- 0.29%. Sirkali taluk soils: from 0.23% to 0.67% mean value – 0.43%, Tharangampadi Taluk OC level was ranged between 0.30% and 4.56% with the mean value of 1.51% and Thirukkuvalai taluk was varied from 0.19% to 0.65% with the mean value of 0.36%. The area where the OC pool is low, medium and high is identified, nutrient index calculated and mapped. The results of present study about organic carbon (OC) of Nagapattinam district revealed that the range was 0.14 to 4.56 % with the mean value of 0.47%. The low content organic carbon was 100% in Kutthalam, 83.58% in Mayiladuthurai taluk, 53.70% in Kilvelur taluk, 100% in Vedaranyam taluk, 90.59% in Nagapattinam taluk, 28.72% in Sirkali, 15.71%in Tharangampadi and 62.86% in Thirukkuvalai. Out of 232257 ha. area of Nagapattinam District, 152584.5 ha area under low level, 67392.7 ha. area under medium level and 12279.8 ha area has sufficient quantity of OC. 66.9% of this district under low level of OC. The inappropriate land use and mismanagement practices including natural calamity are the reason for the depletion and the land users are urged to adapt with best land use practices to reclaim SOC pool in the soil.
