Organic carbon storage in agricultural soils of the Potosi intersalt zone under different types of use

Oscar Ranulfo Ayala Aragón, Milenka Vanessa Almanza López

Abstract

The agricultural soils, producing quinoa, of the intersalar area are in a process of desertification; Due, mainly, to the problems of aridity, wind erosion and the indiscriminate use of machinery in the soil; therefore, the loss of organic C from the soil intensifies, contributing to global warming and the acceleration of climate change, in this region of high vulnerability; in consecuence, it becomes a priority to carry out further studies in these highly vulnerable areas. In this framework, the present investigation was carried out with the objective of evaluating the storage capacity of organic C in the soils of these areas for the different types of use. Based on this, a sampling and physical-chemical analysis has been carried out in soils of the Communities of Chacala, Chita, Keluyo, Opoco and Palaya in resting, cultivated and puruma or virgin soils. Obtaining on average a storage of C from 6 to 20 t ha^-1 and for the case of N from 0.30 to 1.72 t ha^-1. Carrying out the statistical analysis, a non-significance has been determined between the physical-chemical parameters associated with organic C both among the soils of the study communities and in the different land uses. The principal component analysis has established a high correlation between the storage of C and N with the availability of OM and inversely proportional with the apparent density of the soil. One of the determining factors for the low mineralization and decomposition of OM is also due to the particularities of the type of soil leptosol and regosol, characteristic of arid, semi-arid and highly eroded regions as is the case of the soils studied.