Microbiological attributes of a soil under history of swine wastewater application

This research sought to study the effect of applying swine wastewater (SW) on the microbiological attributes of a clayey soil cultivated with physic nut (Jatropha curcas L.). This experimental area was subjected to SW applications for 3 years, followed by fallow for other 2 years. In December 2017, soil collections were carried out and the experiment conducted in randomized complete blocks (RCB) with six treatments and three replicates, namely T1: 0 (control), T2: 40, T3: 80, T4: 120, T5: 160 and T6: 200 m3 ha-1. The evaluated attributes were the following: CFU, diversity, MBC, SBR, qCO2 and FDA. Values of the CFU means demonstrated an increase in the bacterial population density and the diversity pointed to the favoring of bacterial morphotypes already present in the soil, in all treatments under SW application. CFU and SBR were the most effective variables in obtaining results and in the treatment discrimination. The dose with the best metabolic performance was 160 m3 ha-1 due to the better relationship of the parameters previously evaluated in this study.