Effects of cropping on soil properties and organic carbon stock in Deras region, India

Abstract

The agricultural production systems leading to loss of soil organic carbon (SOC) might be contributing to release of CO₂ into the atmosphere. Therefore, an attempt was made to assess the organic carbon stock in the soil profile and related soil properties under different cropping systems like rice–fallow, rice–groundnut, rice–potato, rice–rice, mango and guava orchard in the Deras command in Odisha province, India. Analyses on particle size distribution and pH revealed that soil was sandy loam to sandy clay loam and acidic in nature. The bulk density ranged from 1.54 to 1.79 Mg m⁻³ depending on the soil depth and cropping system; it was lower in the soils of mango and guava orchards. Available water capacity of soils was significantly highest in the rice–rice system in almost every soil depths except in the 0–15-cm layer. The SOC stock was highest within 0–15-cm soil and gradually decreased with increase in depth in each land use systems. In 0–15 cm depth, highest SOC stock (16.80 Mg ha⁻¹) was estimated in rice–fallow system and the lowest (11.81 Mg ha⁻¹) in the soils of guava orchard. In 15–30 cm, it ranged from 8.74 in rice–rice system to 16.08 Mg ha⁻¹ in mango orchard. In the 30–45-cm soil depth, the SOC stock ranged from 6.41 in rice–potato to 15.71 Mg ha⁻¹ in rice–fallow system. The total SOC stock within the 0–60-cm soil profile ranged from 33.68 to 59.10 Mg ha⁻¹ among rice-based systems, highest being in soils under rice–fallow system and the lowest for rice–rice system. The mango and guava orchard soils had 68.53 and 54.71 Mg ha⁻¹ of SOC, respectively, in the 0–90-cm soil depth. The change of SOC stock due to continuous cropping was positive in every land use systems; however, the increase was the highest in rice–fallow system followed by mango orchard.