ABSTRACT
Soils, in addition to supporting agricultural production, are the source of a wide diversity of essential ecosystem functions and services performed by invertebrate organisms. Earthworms play a key role as ecosystem engineers, but little is known about the diversity of the state of Rio Grande do Sul, Brazil, and even less concerning land-use conversion scenarios. Earthworms were sampled using the TSBF method in natural grassland (NG1) in July 2018 and subsequently converted to soybean in an agropastoral system (AP) in December 2018 and July 2019. In July 2019 a nearby natural grassland (NG2) was also sampled and considered as a reference. The earthworms were identified to family, genus and/or species, and the total number of individuals and proportion of native and exotic species were calculated and presented. A total of 583 individuals were collected and seven species were identified: three native species-Kerriona sp.7, Kerriona sp.8, Eukerria rosea; and four exotic/peregrine species-Amynthas corticis, Dichogaster bolaui, Bimastos parvus, Pontoscolex corethrurus. The two native Kerriona species are new to science and were found after the conversion of the area. The other native species (Eukerria rosea), also found after the conversion, had a high number of individuals in the last sample. The results can be related to the availability and changing of resources, due to the conversion of the land use with a high rain preceding the winter season.
Subject(s)
Ecosystem , Oligochaeta , Animals , Brazil , Grassland , SoilABSTRACT
Land-use intensification with a high demand for pesticides is a consequence of human population increase. Feasible alternatives for correct concentrated residues discharge are necessary to avoid soil and water resources contamination. Biobeds are in situ bioreactors for treating pesticide residues, used by several European and American countries due to its low cost and simple construction, whose efficiency has been scientifically proved for over 20 years. This review presents the state of the art of biobeds in Latin America (LA), identifying advances and future research needs. Factors affecting the efficiency of biobeds are discussed, like ideal temperature, moisture, and microbial communities, followed by methods for evaluating the bioreactor's efficiency. It was necessary to adapt this technology to the climatic and economic conditions of Latin-American countries, due to its European origins. Guatemala is the LA country that uses biobeds as official technology. Brazil, Argentina, Costa Rica and Chile are examples of countries that are actively investigating new substrates and pursuing legal aspects for the establishment of the biobeds. Robust scientific evidences may enable farmers start using this technology, which is an environmentally safe system to protect water resources.