Comunidades y grupos funcionales de nemátodos indicadores de la calidad del suelo en dos sistemas de manejo de cafetal en la zona oriental de el salvador

Abstract

The  research  was  carried  out  in  the  period  from  October  2015  to  October  2016, in the Cooperativa Las Marías 93 de R.L. located in the municipality of  Jucuapa,  department  of  Usulután  and  the  municipality  of  Chinameca,  department  of  San  Miguel,  at  an  average  height  of  879  msnm  with  the  objective  of  characterizing  edematous  nematode  communities  in  organic  and  conventional  coffee  production  systems.  Two  organic  farms  of  this  cooperative  and  two  conventional  producers  were  sampled  in  the  rainy  season  favorable  for  the  development  and  growth  of  the  nematodes,  for  each farm soil samples were taken by the zigzag transect method in which physical  parameters  were  measured  -  soil  chemistry  and  the  composition  of  the  nematode  communities  in  each  of  the  systems.  The  alpha  and  beta  diversity of the nematode communities were estimated using the R program packages. The richness of taxonomic groups and the equivalent number of species was found to be related to the percentage of clay present (p <.001). The  abundance  of  taxonomic  groups  of  each  farm  was  also  evaluated,  in  which  differences  were  observed  between  the  nematode  communities  of  the  farms  with  conventional  management  in  relation  to  those  of  organic  management  (p  =  0.002);  and  that  the  apparent  density  influences  the  difference  in  the  composition  of  the  nematode  communities  (p  =  0.042).  When  evaluating  the  abundance  of  each  taxonomic  group  individually,  it  was  observed  that  the  free-living  nematodes  (p  =  0.005)  and  the  genus  Discocriconemella (p = 0.007) showed differences between the systems. A high dominance of colonizing nematodes c-p1 and c-p2 was determined in the organic farms with a higher maturity index than the conventional ones. Therefore, the high presence of vegetal remains provides a high content of organic matter, which generates the favorable conditions to maintain a high diversity and abundance of free living nematodes, being more abundant in the organically managed coffee tree, thus obtaining indices of maturity that demonstrate a better soil quality.