Improvement of soils affected by forest fires using microbiote of native soils

Abstract

Forest fires affect the vegetal and edaphic characteristics of the sites where the accident occurs. A place that has suffered multiple fires since 2002 is the Protected Forest "Loma de Guayabillas". The objective of this research was to evaluate the application of microbial extract from native soils on soils impacted by forest fires. First of all, the areas affected by the last forest fire that occurred in the "Loma de Guayabillas" in 2014 were determined, then, the soils were characterized considering the following parameters: phosphorus, potassium, nitrites, ammonium, nitrates, electrical conductivity, organic matter and microorganisms. For the characterization of the microbial communities, the DNA was extracted, which was amplified using the PCR technique and gel electrophoresis with denaturing gradient (DGGE). The microbiota was extracted from the native soils and the inoculum was implanted according to the four treatments: (T1) Native soil, (T2) Burned soil, (T3) Burned soil with native extract, (T4) Burned soil sterilized with native extract and carried pots with a depth of 20 cm so that the habitat of microorganisms can be simulated. Bean was planted and evaluated: the percentage of germination was higher in native soil with 98.33% as well as the root biomass with 45.39%, foliar biomass with 27.08% in soil burned with native extract and the size total of the plant presented the highest values in this same treatment. It was evidenced that the soils of the Protective Forest present little organic matter, phosphates, total nitrogen due to the burnings suffered during years. The treatment with the highest bacterial activity was T4 Burned soil sterilized with native extract and this inoculum could be normally developed, thus increasing the amount of nitrogen, phosphates, keeping the soil at a neutral pH, allowing to improve the characteristics of the soil affected by the fire.