Qualidade biológica dos solos sob sistemas de uso na Fazenda Experimental de São Domingos - PB.

Abstract

The effects caused by natural processes and anthropic action on soil attributes, mainly on biological and biochemical attributes, are important tools for assessing environmental impacts, serving as subsidies for the implementation of agronomic practices that promote maintenance and, or, improving soil quality. In view of this, it aimed to evaluate the biological attributes (edaphic respiration, biomass carbon and metabolic quotient) indicators of soil quality, in areas under use systems at the Experimental Farm of CCTA / UFCG, located in the city of São Domingos-PB. The work was carried out in areas of the Experimental Farm Rolando Henrique Rivas Castellón of UFCG in the municipality of São Domingos - PB. The work used the DIC, in 9 systems of use of soil in producing areas, being: A1 - system cultivated with fruits for research (FP), A2 - system cultivated with vegetables for practical classes (OAP), A3 - system cultivated with vegetables for research (OP), A4 - system cultivated with fruit for practical classes (FAP), A5 - systems with large cultures for research (GCP), A6 - system cultivated with large cultures for practical classes (GCAP), A7 - production system grazing (PP), A8 - fallow system (P) and A9 - APP Permanent Protection Area - preserved system - legal reserve (RL) reference; where samples were collected with three replications. The values obtained in the different treatments were subjected to analysis of variance by applying the F test at 5% probability, with a significant effect, the treatment averages were compared by the Scott-Knott test, at 5% probability. Performed multivariate analysis of main components with 18 variables, nine chemical attributes (pH, CE, MO, P, Ca, Na, Mg, K, H + Al), six physical attributes (clay, sand, silt, DS, DP and VTP), and three biologicals (respiration, biomass carbon and metabolic quotient). It is noted that the edaphic breathing showed greater in the systems of use of areas A4, A5, A6, A7, A8; intermediate values for A1 and A9, and A3 obtained the lowest values. In the carbon attribute of microbial biomass (CBM), it was observed that the highest results were in A2 and A5, and the others had lower carbon values. The qCO2 values differed between the systems of use of the areas, highlighting the highest results in A4. It was concluded that the biological attributes were responsible for the separation between the use systems and the legal reserve, and the analysis of main components and the similarity dendrogram allowed the joint visualization of chemical, physical and biological attributes and how management, different use systems and soil classes, affected them.