Seasonal occurrence of different Grasshoppers species (Orthoptera: Acridoidea) in Uruguay

This paper aims at knowing the seasonal occurrence of grasshoppers (Orthoptera: Acridoidea) in Uruguay. The populations of these native herbivores are generally in equilibrium, although population increases were recorded under certain conditions, causing significant economic loss. The population was monitored during five seasons on sites located in the departments of Florida and Durazno. The insects were categorized into young nymphs (I, II and III), older nymphs (IV and V), and adults. At each sampling time, data from the different sites were grouped to calculate the percentage of each category. Twenty-six species were collected, eight of which were abundant. Borellia bruneri (Rehn, 1906), B. pallida (Bruner, 1900), Dichroplus pratensis Bruner, 1900 and D. elongatus Giglio-Tos, 1894 proved to be univoltine. More than one generation of Baeacris pseudopunctulatus (Ronderos, 1964), Orphulella punctata (De Geer, 1773), Scotussa lemniscata (Stål, 1861) and D. conspersus Bruner, 1900, was recorded per year in some seasons. The first births of B. bruneri, B. pallida, D. pratensis, D. conspersus, S. lemniscata and B. pseudopunctulatus occurred in October, whereas for D. elongatus and O. punctata they happened in November. Considering the eight species, young and older nymphs predominated until early December and from late December to early January, respectively. Adulthood was predominant since the end of January. These results are the basis for establishing a monitoring plan. In order to determine the need for control and to avoid irreparable loss, samples must be intensified from early November to the beginning of December, when the young nymphs are no longer predominant

Evaluación de la densidad, biomasa y diversidad de la macrofauna del suelo en diferentes sistemas de producción

Orientadores: PhD Ing. Agr. Nora Altier, Dr. Ing. Agr. Alejandro Morón, Dra. Lic. Claudia RodríguezTribunal: Ing. Agr. Ricardo Cayssials, Q. F. MSc. Bioquím. Alicia Arias, PhD Ing. Agr. Fernando García, Dr. lic. Alejandro Brazeir

Influence of aerobic treated manure application on the chemical and microbiological properties of soil

Aim of study: This study evaluated the effect of the application of liquid aerobic treated manure (continuous liquid composting, CLC) on physical, chemical and biological soil properties, with the objective of monitoring changes induced by soil management with CLC as a biofertilizer. Area of study: Colonia, Uruguay (lat. 34,338164 S, long. 57,222630 W). Material and methods: Soil?s chemical properties, including nitrogen mineralization potential (NMP) and 15 microbiological properties (microbial biomass carbon, MBC; mesophylic aerobic bacteria; actinobacteria; filamentus fungi; fluorescein diacetate hydrolysis; dehydrogenase; with NMP; acid and alkaline phosphatase; cellulolose degraders; P-solubilizing bacteria; nitrifying; denitrifying and free-living N-fixing microorganisms; glomalin; and soil-pathogenicity index, SPI) were evaluated in two sites with similar cropping history, with one and three years of respective CLC application. Main results: CLC application had significant effects on soil microbial biomass (p<0.05), soil enzyme (p<0.1) and functional groups activity (p<0.05). SPI decreased in both sites with CLC application. No significant variations were detected for the chemical variables, with the exception of NMP, which was significantly high (p<0.05) in soil treated with CLC at both sites. Research highlights: The improved biological soil properties analyzed (MBC, soil enzyme activities and SPI, together with NMP) emerged as reasonable indicators to assess and monitor the effects of CLC applicatio