Inoculation with a soil fungus accelerates decomposition of avocado cv. Hass leaf litter in three plantations in Colombia

  • Álvaro Tamayo-Vélez Colombian corporation for agricultural research, AGROSAVIA, Colombia
  • Guillermo Correa-Londoño Universidad Nacional de Colombia, Sede Bogotá, Agricultural Sciences Faculty, Bogotá, Colombia
  • Nelson Walter Osorio Universidad Nacional de Colombia, Science Faculty, Bogotá, Colombia
Keywords: Persea americana, litter bags, litter decomposition, nutrient cycling

Abstract

The objective of this study was to evaluate the effect of a fungal inoculation on the litter decomposition in three plantations of avocado (Persea americana) cv. Hass in Colombia at different altitudes (Támesis 1340 m, Jericó 1900 m, and Entrerríos 2420 m). These processes are key in the proper functioning of soil biogeochemical cycles. The litter was either uninoculated or inoculated with the fungus Mortierella sp., then transferred into litter bags and finally deposited in the field sites where remained for 430 days. Residual dry matter (RDM) and nutrient content was monitored overtime. Five regression models of litter decomposition were employed: single, double, and triple exponential models and two continuous models. Although, all models properly fitted the data variation, the double exponential was the most effective based on regression parameters (mean  square error and Akaike index). In all three sites the rate of decomposition was higher when the litter was  inoculated with the fungus. Thus, the RDM was significantly lower when the litter was inoculated with  Mortierella sp. At day 430, the uninoculated RDM in Tamesis, Jerico, and Entrerrios was 0.48, 0.47, and 0.50,  respectively; while the inoculated RDM was 0.47, 0.44, and 0.46, respectively. The rate of decomposition  followed the decreasing sequence: Jericó > Támesis > Entrerríos. The nutrient release pattern was: K > Ca > Mg >  N > P > Cu > Mn > Zn > Fe. While K was rapidly released, Ca, Mg, and N were slowly released; P, Cu, Mn, Zn,  and Fe were immobilized during the decomposition process. However, fungal inoculation on the litter  significantly reduced the magnitude of nutrient accumulation for P, Mg, S, Mn, and Zn. This effect was variable  overtime and among sites. Litter N and P contents and the N:P ratio were good indicators of the decaying  process.

Published
2019-05-17
How to Cite
Tamayo-Vélez, Álvaro, Correa-Londoño, G., & Osorio, N. (2019). Inoculation with a soil fungus accelerates decomposition of avocado cv. Hass leaf litter in three plantations in Colombia. AUC Geographica, 54(1), 24-36. https://doi.org/10.14712/23361980.2019.3
Section
Original Articles