Adriana Maria de Aquino

Soil macrofauna in cover crops of figs grown under organic management

A fauna do solo tem papel importante em sistemas orgânicos, atraves dos seus efeitos na decomposicao da materia orgânica, mineralizacao de nutrientes e condicionamento fisico do solo. Este trabalho avaliou a densidade e a diversidade da macrofauna edafica sob tipos de cobertura do solo em areas cultivadas com Ficus carica L. sob manejo orgânico do solo. A macrofauna foi coletada em areas de 0,25 × 0,25 m e amostraram-se as camadas de material vegetal e solo ate a profundidade de 0,3 m, nos meses de marco e setembro de 2001. Os tratamentos constaram de cobertura viva com grama batatais (Paspalum notatum), cobertura viva de siratro (Macroptilium atropurpureum) e cobertura morta formada por palha de grama batatais. A mais alta densidade da macrofauna e a mais baixa diversidade foi observada em grama batatais, sendo mais de 80% dessa fauna de formigas, o que caracteriza o solo sob influencia desta cobertura como o de mais baixa diversidade funcional e qualidade, comparado as outras coberturas.

Análise conjunta de atributos físicos e biológicos do solo sob sistema de integração lavoura-pecuária

The objective of this work was to evaluate the effects of the integrated crop-livestock system on the morphological, physical and biological properties of soil. The experiment was carried out in Dourados, Mato Grosso do Sul State, Brazil, in a typic Hapludox soil. The following systems were sampled: grain crop under conventional soil tillage system, integrated crop-livestock system under no-tillage, continuous Urochloa decumbens (Syn. Brachiaria decumbens) pasture and natural system. In each system, a trench was opened in order to detect morphological changes caused by different management, using the cultural profile method. Assessments of soil macroinvertebrates were done according to the method Tropical Soil Biology and Fertility. Undisturbed soil samples were also used to assess the physical attributes of soil (soil density, total porosity, macro and microporosity). Among the cultivated systems, better soil structure was observed in the integrated crop-livestock system, in the layers 0-0.1 and 0.1-0.2 m. The systems under crop-livestock and pasture continuously cultivated favored a more biologically active soil environment, among the other agricultural systems. The visualization of soil attributes showed that crop-livestock integration is a promising strategy to develop sustainable production systems and that the period of two years of management is considered suitable for crop-pasture rotation.

Macrofauna invertebrada do solo em sistema integrado de produção agropecuária no Cerrado

The objective of this work was to evaluate the density and diversity of soil invertebrate macrofauna in a crop-livestock rotation production system under no-tillage. The field experiment was performed in Dourados, Mato Grosso do Sul State, Brazil, on a Typic Hapludox soil, in parcels under a conventional monoculture system, a crop-livestock rotation system under no-tillage and continuous pasture, and a native vegetation fragment. The evaluations were conducted in January 2002, June 2002, January 2003 and July 2003, according to the method recommended by the Tropical Soil Biology and Fertility (TSBF) program. Systems with less anthropic interference showed greater abundance and richness of soil invertebrate macrofauna.

Agricultura orgânica em áreas urbanas e periurbanas com base na agroecologia

A agricultura orgânica com base na agroecologia e o mote tecnologico adequado a realidade dos agroecossistemas urbanos. Este artigo ressalta a necessidade de se desenvolver tecnologias e insumos especificos. A partir de experiencias com agricultura urbana em diferentes paises em desenvolvimento, evidencia-se a necessidade de se buscar capacidades locais e apoio do poder publico, especialmente nas iniciativas da sociedade organizada e mobilizada para a producao agricola urbana.

Soil oribatid mite communities under three species of legumes in an ultisol in Brazil.

Oribatid mite densities in the topsoil and their activity at the soil surface were monitored under three species of perennial legume cover crops namely, Arachis pintoi, Macroptilium atropupureum and Pueraria phaseoloides, grass (Panicum maximum) and bare plots on three occasions in 1998 and 1999 in a derived savanna zone in Brazil. Both densities and activity at the soil surface were higher in the early but cool dry season in April 1998 than in the early wet but warm season in November 1998 and 1999. Three taxonomic groups of macropyline oribatid mites, namely Nothrus, Archegozetes and Masthermannia as well as a brachypyline taxon, Scheloribates were suggested as possible indicators of effect of legumes on soil biota because their populations increased under the legumes and/or their residues. Nothrus in particular increased in abundance more than any other taxon in the presence of residues of A. pintoi. Each legume supported a unique oribatid mite community in terms of species composition and relative abundance. The large numbers of Archegozetes trapped from all the legume and grass plots in April and November 1998 were also attributed to highly conducive conditions provided by the vegetation cover and their residues. The results suggest that the oribatid mite community of the study area was numerically stable as the peak populations of different species were not synchronized. Many taxonomic groups of pycnonotic brachypyline mites were absent. Legume cover crops, especially A. pintoi, and their residues have potential in restoring oribatid mite populations to precultivation levels.

Populações de oligoquetos (Annelida: Oligochaeta) em um Latossolo Vermelho submetido a sistemas de uso do solo

This paper objective was to evaluate earthworm population dynamics in agricultural and livestock systems using as reference an area under native vegetation. The work was carried out in Dourados, MS, in a Typic Hapludox soil under conventional soil tillage (CT), no-tillage (NT), cropping/livestock integration (CLI), a continuous pasture (CP), and a natural system (NS). Samples were taken during summer and winter cropping seasons between 2000 and 2003. SPD, SILP, and PC systems benefited the development and establishment of earthworm population. NS system showed the largest earthworm population, being the majority of organisms from Enchytraeidae family. Among the systems, SPD also benefited the occurrence of organisms from Enchytraeidae family.

Serapilheira e teores de nutrientes em argissolo sob diferentes manejos no norte do Piauí

This work aimed to evaluate litter deposition and quantify contents of N, P, K, Ca and Mg in agroforest systems six (AFS6) and ten (AFS10) years after implantation, in three-year old ecological based systems (ES3), slash-and-burn agriculture (SBA) and native forest (NF), all located in Esperantina, northern region of Piaui, Brazil. Collections were carried out in the wet and dry seasons of 2007. The litter was separated into leaves and branches and weighted to estimate the deposition on the soil. The highest leaf depositions were found in NF (3.8 Mg ha-1), in the dry season, whereas for branches, in the AFS10 (2.2 Mg ha-1), in the wet season. AFS showed the highest nutrient contents in the litter fractions, and, among them the N concentration was higher than the others, in both seasons. The estimate transfer of nutrients by the litter followed the sequence N>Ca>K>P>Mg. The values for litter deposition and contents and input of nutrients in the AFS systems show the contribution of the agroforest management to soil quality and the economic sustainability of the system.

Response of soil mites to organic cultivation in an ultisol in southeast Brazil

Soil-dwelling mites of four plots under organic management were investigated in April and December 1998 and in December 1999. Their populations were compared with mite populations in a pasture and forest in the vicinity. It was observed that there was always an initial reduction in the populations of soil mites and in the activity of the epigeic forms whenever a plot was opened up and disturbed mechanically in preparation for cultivation, irrespective of previous organic inputs. With time, the densities and activities of mites recovered under organic management. The uropodine and oribatid mites in particular benefited more from organic management than gamasine and actinedid mites. Uropodine mites increased tremendously under banana where there was fresh cow dung manure. Oribatid mite species Nothrus seropedicalensis and Archegozetes magnus were dominant in organic plots where the soil was moist and temperatures were lower than the ambient. Protoribates rioensis was dominant in organic plots where the soil was drier and temperatures were higher than the ambient. Galumna was the most active oribatid taxon on the floor of all plots, with the highest activity recorded under maracuja and in pasture plots. The results suggest that while densities and activities of soil mites increased in the organic plots, the community structure and recruitment period of oribatid mites were altered. Oribatid mite diversity was higher in the organic plots than in the pasture but lower than in the forest, where Belba sp. and many Eremobelboid brachypiline genera were present, but absent in the organic plots and pasture.

The Structural and Functional Biodiversity of Soil: An Interdisciplinary Vision for Conservation Agriculture in Brazil

Brazil is a country of continental dimensions recognized for its extraordinary diversity of plants, vertebrates and insects. The belowground biodiversity, which comprises soil invertebrates and micro-organisms, is also large and vastly unknown. Agroecosystems developed under conservation practices are dependent on biodiversity for their sustainability. They also play an essential role in biodiversity conservation, which is considered a valuable heritage of tropical countries like Brazil.

Populações de minhocas em sistemas agroflorestais com café convencional e orgânico

Objetivou-se, neste estudo, determinar se as populacoes das minhocas sao alteradas em funcao do manejo do cafe (Coffea arabica) em Turrialba, CostaRica. Os seguintes sistemas de cultivo do cafe foram estudados: a pleno sol (PS) e sombreado com eritrina, Erythrina poeppigiana (E); terminalia, Terminalia amazonia (T) e casha, Chloroleucon eurycyclum (Ab). A hipotese foi de que o manejo orgânico do cafe e o fornecimento da serapilheira de melhor qualidade favoreceria a diversidade, a densidade e a biomassa das minhocas. As populacoes das minhocas foram alteradas, em funcao do manejo com insumos sinteticos ou orgânicos , sendo a densidade menor no cafe a pleno sol. Entre as especies utilizadas no sombreamento, a eritrina parece limitar a abundância das minhocas. Contudo, favorece a diversidade das mesmas, tendo sido registradas duas especies de minhocas com papeis ecologicos diferenciados, Pontoscolex corethrurus, endogeica e Metaphire californica, anecica; ao contrario dos demais tratamentos, onde somente foi encontrada a primeira especie, considerada cosmopolita com distribuicao pantropical.