Isaac Scientific Publishing

Annals of Advanced Agricultural Sciences

Soil Quality Indexes Response to Land Use Change in Puerto Ayacucho, Venezuelan Amazonia

Download PDF (216.7 KB) PP. 54 - 64 Pub. Date: November 3, 2017

DOI: 10.22606/as.2017.12002


  • Danilo López-Hernández*
    Universidad Central de Venezuela, Instituto de Zoología y Ecología Tropical, Laboratorio de Agroecología, Apdo. 47058, Caracas 1041A, Venezuela.


Shifting cultivation (SF) or “conuco” is a form of crop cultivation of native Amerindian in Venezuelan Amazonia. SF is practiced in the primary forest as traditional conuco (TC) or in forestfallow as conuco in fallow (CF). Soil samples were random collected from previously settled conucos (TC and SF) and controls, and compared for fertility parameters (pH, C, N, available-P, Nmineralization), microbial biomass (C,N) and enzymatic activities. In CF, soil organic matter was drastically reduced (58%), whereas in the TC there was no significant difference with the control. Soil microbial biomass did not present a consistent trend within TCs, however, a drastic decrease was presented in the CF (59%). Phosphatase and urease were higher in the traditional conuco than in the primary forest, however the activities of both enzymes drastically declined in the conuco in fallow. Soil enzyme activity and microbial biomass were strongly affected by land degradation and represent very sensitive indicators of soil disturbance.


Conuco, microbial biomass, phosphatase activity, deforestation, swidden cultivation.


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