Avaluació de l’efecte de diferents esmenes orgàniques en la microbiota i la capacitat de segrest de carboni en diferents sòls agrícoles

Abstract

On behalf of the actual climatic context, it is needed to find new ways to decrease or mitigate the greenhouse gases (GHG). For this, soils are of great importance, due to their ability to sequester carbon and thereby mitigate climate change. However, since the industrial revolution, there has been a decline on the original soil’s carbon reserves as a consequence of unsustainable agriculture practices. That is why it is needed to implement new sustainable soil management in order to maintain soil’s functionality. This project arises from this mentioned problem and it is focused on the importance of adding organic composts to the soil. These compounds can contribute to ameliorating the soil’s quality and its related ecosystem’s services. The main goal has been to determinate the effect of the different organic composts on the quality parameters, the microbiome and the sequestering capacity of representative soils from the Tarragona’s province. The chosen soils have been: cereal field (Conca de Barberà), vineyard (Priorat) and vegetable patch (Baix Camp). The added composts have been a fungi inoculum made through the Biologically Enhanced Agricultural Management (BEAM), an organic compost made from microbial carbonization (CM) and the mix of both. In order to accomplish the goal, the study has been divided in two parts. First of all, there has been done a bioassay with the aim of seeing how the different organic composts effect in the different agricultural soils. Secondly, it has been sampled an experimental cereal field where these same different composts were applied. So that, it has been possible to see the composts effect in vitro and in vivo. A physicochemical and a biochemical characterization of the soil’s samples and a plant analysis of the bioassay have been done. It has been conducted an ANOVA statistical analysis of the obtained results in order to see if there are significant differences between soils or treatments. Moreover, a Tukey’s post hoc test and a principal component analysis have been carried out. Cereal’s field only the variables that present significant difference for the treatment factor in the bioassay have been analysed. On the bioassay it has been possible to see that the application of the CM and the BEAM+CM treatments has implied an increase on some of the soil’s analysed characteristics such as the cationic exchange capacity and the most essential minerals for plants (N, P and K). Furthermore, an increase of the variables related with “organic reserve”: oxidizable organic carbon, total organic carbon, CaCO3, glomalin (total and easily extracted) and vegetal biomass. Regarding the results of the experimental field, it has not been possible to see significant differences compared to the initial sampling. An increase of the oxidizable organic carbon and the microaggregates stability (0.25-2 mm) has been seen due to the application of the CM and the BEAM+CM composts