RESUMO
In the Amazonian periphery, there are sources of numerous disservices, including deforestation, loss of wildlife habitat and biodiversity erosion. However, there are great opportunities to adopt appropriate agricultural management practices to take advantage of the benefits of ecosystem services for sustainable agricultural intensification. Thus, the aim of this work was to evaluate the effects of certain ecosystem services provided by combined use of legumes with residue of low- and high-quality on soil quality indicators, nitrogen use efficiency and sustainability of maize grain yield in infertile tropical soil. The overarching objective is to determine how ecosystem services can contribute to the improvement of land-use policy to ensure the sustainability of cultivated lands, in such a way that forest can be preserved by avoiding deforestation of other new areas through shifting cultivation systems. Four leguminous tree species were used, two with high-quality residues Leucaena leucocephala (leucaena) and Gliricidia sepium (gliricidia) and two with low-quality residues Clitoria fairchildiana (clitoria) and Acacia mangium (acacia). Maize grain yield was evaluated between 2011 and 2017 in these treatments. In 2018, to assess how ecosystem services affect crop performance, the treatments were divided into ten treatments with and without urea. We conclude that increased uptake of inorganic and organic N by maize resulting from improvement of the soil quality indicators may allow agricultural intensification. This improvement can help meet the challenges of sustainability and feasibility of agroecosystems of the Amazonian periphery by making the agroecosystem more productive year by year. Therefore, our results confirm that the utilization of an ecosystem services style approach can help meet the challenges of sustainability and feasibility in agrosystems of the Amazonian periphery. In addition, these results can contribute to the development of land-use policy in the Amazonian periphery, aiming for the intensification of agriculture in cropped areas to avoid deforestation of new areas from shifting cultivation systems.
RESUMO
The nitrogen-fixing bacterial strain UFLA 01-1174T was isolated from nodules of Campsiandra laurilifolia Benth. originating from the Amazon region, Brazil. Its taxonomic position was defined using a polyphasic approach. Analysis of the 16S rRNA gene placed the strain in the Bradyrhizobium genus, the closest species being B. guangdongense CCBAU 51649T and B. guangzhouense CCBAU 51670T, both with 99.8% similarity. Multilocus sequence analysis (MLSA) of recA, gyrB, glnII, rpoB, atpD, and dnaK indicated that UFLA 01-1174T is a new species, most closely related to B. stylosanthis BR 446T (94.4%) and B. manausense BR 3351T (93.7%). Average nucleotide identity (ANI) differentiated UFLA 01-1174T from the closest species with values lower than 90%. The G + C content in the DNA of UFLA 01-1174T is 63.6 mol%. Based on this data, we conclude that the strain represents a new species. The name proposed is Bradyrhizobium campsiandrae, with UFLA 01-1174T (= INPA 394BT = LMG 10099T) as type strain.
Assuntos
Bradyrhizobium/classificação , Fabaceae/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , Bradyrhizobium/genética , Brasil , DNA Bacteriano/genética , Genes Bacterianos , Tipagem de Sequências Multilocus , Bactérias Fixadoras de Nitrogênio/genética , RNA Ribossômico 16S/genética , Nódulos Radiculares de Plantas/microbiologia , Especificidade da EspécieRESUMO
Acacia mangium forms two kinds of mycorrhizal symbiosis, a arbuscular mycorrhizal fungi (AMFs) type and another with ectomycorrhizal fungi (fECTOs). The present study aimed to select different AMFs species and fECTOs isolates for effective symbiosis with A. mangium, which provide seedlings well colonized, nodulated and developed. Experiments were conducted in a greenhouse at Embrapa Agrobiology, one for AMF species selection and another for fECTOs, using a randomized block design with five replicates. Treatments were species AMFs (Acaulospora laevis, Acaulospora morrowiae, Entrophospora colombiana, Entrophospora contigua, Gigaspora margarita, Glomus clarum, Scutellospora calospora, Scutellospora heterogama, Scutellospora gilmorei and Scutellospora pellucida) or fECTOs isolated (UFSC Pt116; UFSC Pt24; UFSC Pt193; O 64ITA6; UFSC Pt187 and O 40ORS 7870). The AMFs species that promoted greater vegetative growth, mycorrhizal colonization and more effective symbioses were S. calospora, S. heterogama, S. gilmorei e A. morrowiae. The fECTOs not demonstrated effectiveness in promoting growth, but the isolate O64-ITA6 (Pisolithus tinctorius) provided greater colonization. Seedlings of A. mangium have high responsiveness to inoculation with AMFs and depends on high root colonization, between 40 and 80%, to obtain relevant benefits from symbiose over nodule formation and growth.
Acacia mangium forma dois tipos de simbiose micorrízica, uma com fungos micorrízicos arbusculares (FMAs) e outra com fungos ectomicorrízicos (fECTOs). O presente trabalho teve o objetivo de selecionar diferentes espécies de FMAs e isolados de fECTOs para simbioses eficientes com A. mangium, que proporcionem mudas bem micorrizadas, noduladas e desenvolvidas. Experimentos foram instalados em casa de vegetação na Embrapa Agrobiologia, sendo um para a seleção de FMAs e outro para fECTOs, utilizando delineamento de blocos casualizados, com 5 repetições. Tratamentos foram espécies de FMAs (Acaulospora laevis, Acaulospora morrowiae, Entrophospora colombiana, Entrophospora contigua, Gigaspora margarita, Glomus clarum, Scutellospora calospora, Scutellospora heterogama, Scutellospora gilmorei e Scutellospora pellucida) ou isolados de fECTOs (UFSC Pt116; UFSC Pt24; UFSC Pt193; O 64ITA6; UFSC Pt187 e O 40ORS 7870). As espécies de FMAs que promoveram maior crescimento vegetativo, colonização micorrízica e apresentaram simbiose mais eficiente foram S. calospora, S. heterogama, S. gilmorei e A. morrowiae. Os fECTOs não demonstraram eficiência na promoção do crescimento, mas o isolado O64ITA6 (Pisolithus tinctorius) proporcionou maior colonização micorrízica. Mudas de A. mangium são muito responsivas a inoculação de FMAs e dependem de elevada colonização micorrízica, entre 40 e 80%, para ob
RESUMO
Acacia mangium forms two kinds of mycorrhizal symbiosis, a arbuscular mycorrhizal fungi (AMFs) type and another with ectomycorrhizal fungi (fECTOs). The present study aimed to select different AMFs species and fECTOs isolates for effective symbiosis with A. mangium, which provide seedlings well colonized, nodulated and developed. Experiments were conducted in a greenhouse at Embrapa Agrobiology, one for AMF species selection and another for fECTOs, using a randomized block design with five replicates. Treatments were species AMFs (Acaulospora laevis, Acaulospora morrowiae, Entrophospora colombiana, Entrophospora contigua, Gigaspora margarita, Glomus clarum, Scutellospora calospora, Scutellospora heterogama, Scutellospora gilmorei and Scutellospora pellucida) or fECTOs isolated (UFSC Pt116; UFSC Pt24; UFSC Pt193; O 64ITA6; UFSC Pt187 and O 40ORS 7870). The AMFs species that promoted greater vegetative growth, mycorrhizal colonization and more effective symbioses were S. calospora, S. heterogama, S. gilmorei e A. morrowiae. The fECTOs not demonstrated effectiveness in promoting growth, but the isolate O64-ITA6 (Pisolithus tinctorius) provided greater colonization. Seedlings of A. mangium have high responsiveness to inoculation with AMFs and depends on high root colonization, between 40 and 80%, to obtain relevant benefits from symbiose over nodule formation and growth.
Acacia mangium forma dois tipos de simbiose micorrízica, uma com fungos micorrízicos arbusculares (FMAs) e outra com fungos ectomicorrízicos (fECTOs). O presente trabalho teve o objetivo de selecionar diferentes espécies de FMAs e isolados de fECTOs para simbioses eficientes com A. mangium, que proporcionem mudas bem micorrizadas, noduladas e desenvolvidas. Experimentos foram instalados em casa de vegetação na Embrapa Agrobiologia, sendo um para a seleção de FMAs e outro para fECTOs, utilizando delineamento de blocos casualizados, com 5 repetições. Tratamentos foram espécies de FMAs (Acaulospora laevis, Acaulospora morrowiae, Entrophospora colombiana, Entrophospora contigua, Gigaspora margarita, Glomus clarum, Scutellospora calospora, Scutellospora heterogama, Scutellospora gilmorei e Scutellospora pellucida) ou isolados de fECTOs (UFSC Pt116; UFSC Pt24; UFSC Pt193; O 64ITA6; UFSC Pt187 e O 40ORS 7870). As espécies de FMAs que promoveram maior crescimento vegetativo, colonização micorrízica e apresentaram simbiose mais eficiente foram S. calospora, S. heterogama, S. gilmorei e A. morrowiae. Os fECTOs não demonstraram eficiência na promoção do crescimento, mas o isolado O64ITA6 (Pisolithus tinctorius) proporcionou maior colonização micorrízica. Mudas de A. mangium são muito responsivas a inoculação de FMAs e dependem de elevada colonização micorrízica, entre 40 e 80%, para ob