Physical properties of soil in the early stage of an agroforestry system in the High Andean zone

Abstract

In  Nariño,  Colombia,  land  use  has  generated  some  problems  such  as  erosion,  compaction,  lack  of  fertility,  among  others,  so  it  is  necessary  to  search  for  alternatives  to  mitigate  these  impacts.  The  objective  of  this  study was to evaluate some physical properties of the soil in an agroforest system  with  Morella  pubescens  (Humb.  &  Bonpl.  ex  Willd.)  Wilbur  with  Smallanthussonchifolius (Poepp.)  H.Rob,  in  the  experimental  farm  of  Botana,  in  the  city  of  Pasto,  Nariño,  where  the  bulk  density,  real  density,  total porosity, structural stability properties and distribution of aggregates were  analyzed.  The  datas  were  obtained  in  two  phases:  f1  and  f2  before  and after agroforestry system implementation, respectively. A randomized complete block design with three treatments and three replications were used. The treatments corresponded to plant densities, T1: S sonchifoliuos, sowed  to  1x1m,  T2:0.8x0.8m  y  T3:0.5x0.5m,  with  three  replications.  M  pusescens was stablished to 4x4m between plants and 9 m between rows and  the  control  (f1).    The  statistics  have  differences  between  f1  (control)  and f2 (treatments), to the structural stability properties and distribution of  aggregates.  The  ground  suffered  a  structural  stability  change  to  stable  lightly  (0.97  D.P.M)  in  f1  to  a  stable  moderate  (2.53  D.P.M),  in  f2.  The  distribution of aggregates passed to 60% in f1 to 70.3% in f2, with a media aggregation  status.  The  different  agroforest  systems  management  could  help,  in  the  long  term,  by  improving  the  structure  of  the  ground  through  the vegetal material of arboreal component, the application of a minimum farming and the addition of organic matter.