Carbon retained by litter and roots in different land uses in the semiarid region of Chaco province

Flora E. Céspedes Flores ^{1, 2*}, Juan A. Fernández¹, Laura Giménez¹, Edgardo A. Leonhardt³, Aldo C. Bernardis¹

ABSTRACT

Agricultural conservation practices and various traditional production systems can significantly increase organic carbon in soils. A study was carried out in order to evaluate the accumulation of carbon in root and litter biomass with different land uses. The essay was conducted in the west of the Chaco province, Argentina. The following land uses (treatments) were evaluated: natural grassland, pasture, silvopastoral system, semi-arid native forest and cultivated field. Pits were made along a transect and the following strata were sampled: 0 to 0.05; 0.05 to 0.15; 0.15 to 0.3; and 0.3 to 0.6 m. A randomized complete block design was used, with 3 replicates. The results were analyzed with ANOVA and Tukey test (p ≤ 0.05). Litter carbon was higher in the pasture (670.7 kg ha^-1) and silvopastoral system (944.1 kg ha^-1) compared to values recorded in the natural grassland, native forest and cultivated field, which reached 300.3 kg ha^-1; 200.3 kg ha^-1; and 500.24 kg ha^-1, respectively. The carbon contribution from the roots was greater in the first two strata sampled (0 to 0.05m and 0.05 to 0.15m). The native forest recorded values of 3156.9 and 2779.2 kg ha^-1, while the silvopastoral system reached values of 2448.4 and 1228.9 kg ha-1 at 0.05 m and 0.15 m depth, respectively. These two land uses recorded the highest root contributions of carbon.

 Key words: grassland, silvopastoral system, native forest, carbono stock, arid Chaco

¹ Facultad de Ciencias Agrarias, Universidad Nacional del Nordeste (UNNE), Sargento Cabral 2131. C.P. 3400, Pcia. Corrientes, República Argentina.

² Estación Experimental Agropecuaria INTA, Colonia Benítez, Av. Marcos Briolini S/N. C.P. 3505, Pcia. Chaco, República Argentina.

³ Agencia de Extensión Rural Pampa del Infierno, INTA Sáenz Peña, 9 de Julio N° 558, Pampa del Infierno, C.P. 3708, Pcia. Chaco, República Argentina.

^*Autor para correspondencia E-mail: fcespedes@agr.unne.edu.ar; cespedes.flora@inta.gob.ar