<b>Arbuscular mycorrhizal fungi within agroforestry and traditional land use systems in semi-arid Northeast Brazil</b> - doi: 10.4025/actasciagron.v35i3.16213

Abstract

ABSTRACT. The diversity of arbuscular mycorrhizal fungi (AMF) can be a critical factor in enhancing both the productivity and the diversity of plants in ecosystems, and the plants in the ecosystem also strongly influence the occurrence of these fungi. The relationships between different land use systems and AMF communities in the semi-arid region of the State of Paraíba, NE Brazil were evaluated. The experiment followed a split-plot randomized block design, with four replicates. The main plots were defined by the presence or absence of trees (gliricidia and maniçoba), while the split plots were defined by three land use systems: 1) traditional cropping of maize + beans, 2) buffel grass pasture, and 3) prickly pear forage crop. The presence of trees increased sporulation, mycorrhizal colonization and the production of infective propagules of AMF in all three land use systems. Greater production of glomalin-related soil protein (GRSP) occurred in the prickly pear plots regardless of the presence or absence of trees. Species belonging to the Glomus genus predominated regardless of the presence of trees, land use systemor soil sampling period.Keywords: mycorrhizae, agroecosystems, glomalin.Fungos micorrízicos arbusculares em sistemas agroflorestais e sistemas tradicionais de uso da terra no semi-árido do nordeste do Brasil RESUMO. A diversidade de fungos micorrízicos arbusculares (FMA) pode ser um fator crucial para aumentar a produtividade e diversidade de plantas nos ecossistemas, e em contrapartida, as plantas também influenciam fortemente a ocorrência desses fungos. Foi avaliada a relação entre diferentes sistemas de uso da terra e as comunidades de FMA na região semi-árida do Estado da Paraíba, Nordeste do Brasil. O experimento foi conduzido em esquema de parcelas subdividas em blocos casualizados, com quatro repetições. A presença ou ausência de árvores (gliricídia e maniçoba) foram parcelas principais e três sistemas de uso da terra foram as subparcelas: 1) cultivo tradicional de milho + feijão; 2) pastagem de capim buffel e 3) cultivo de palma forrageira. A presença das árvores aumentou a colonização micorrízica, esporulação e produção de propágulos de FMA em todos os três sistemas de uso da terra. Houve maior produção de proteínas do solo relacionadas à glomalina pelos FMA em parcelas com o cultivo de palma forrageira, independentemente da presença das árvores. Espécies de FMA pertencentes ao gênero Glomus predominaram independentemente da presença das árvores, do sistema de uso da terra e do período de amostragem do solo.Palavras-chave: micorrizas, agroecossistemas, glomalina.

Arbuscular mycorrhizal fungi in soils of arboreal Caatinga submitted to forest management

“…The same result was observed for Glomus macrocarpum, which was the dominant species in the community (Table 3). The dominance of the G. macrocarpum in the Caatinga can be related to its great adaptive ability (Ceola, 2015) and resistance to natural stress promoted by the climatic and environmental conditions of this biome (Teixeira-Rios et al, 2013; Sousa et al, 2013).…”

“…In the Caatinga, the presence of AMF plays an important role in the establishment and maintenance of vegetation (Mello et al, 2012;Sousa et al, 2013), providing constitutes a mechanism for the adaptation of plants to soils with nutrient restrictions. Thus, arbuscular mycorrhizal fungi present variable tolerance to changes in the environment and soil management, responding to these modifications with changes in the number of propagules (Mello et al, 2012).…”

Arbuscular mycorrhizal fungi activity in Haplic Luvisol on the semi-arid region of Pernambuco Brazil

“…The MPN found by Sousa et al (2013) was high compared to that found in this study, it ranged from 39 propagules cm -3 , having as land use system the palm without trees, to 540 propagules cm -3 , in the presence of buffel grass with trees. According to Ganesan & Veeralakshmi (2006), this value for the buffel grass may have been justified by the fact that it is considered a good and the soil samples of the Haplic Luvisol (Sertania soil) showed mycorrhizal activity with a significant number of glomerospores and infective propagules of AMF.…”

“…Sousa et al (2011), working with Luvisol in the semi-arid region of Paraíba under savanna vegetation, used as pasture, noted that the highest glomalin levels (0.97 mg g soil -1 ) are possibly explained by the pH of 6.08; since fungi tend to predominate in acid soils, as in alkaline soils there is more competition with bacteria and other organisms (Weil & Brady, 2016). Sousa et al (2013) found that in the relationship between the diversity of land use systems and the AMF communities in the semi-arid region of Paraíba, the largest contents of SPRG were recorded in the palm production system, getting around 1.14 mg g soil -1 , in which plants also showed a higher percentage of mycorrhizal colonization, suggesting that large amounts of photosynthates were being allocated to the AMF by plants, what possibly stimulated the production of this protein. Mergulhão et al (2010), working with waste and gypsum mining soil in the semi-arid of Pernambuco, in the region of the Araripe, found values ranging from 0.01 mg g soil -1 , in the waste, to 0.9 mg g soil -1 , in the caatinga preserved for easily extractable protein, and values ranging from 2.8 mg g soil -1 , in the waste, to 4.3 mg g soil -1 , in the caatinga preserved for total protein content.…”

“…Sousa (2013), evaluating the relationship between the diversity of land use systems and AMF communities in the semi-arid region of Paraíba, concluded that the presence of trees favored the sporulation, the mycorrhizal colonization and the number of infective propagules of AMF in the land use systems. Gattai et al (2011), working with lead-contaminated soils in the semi-arid region of northeastern Brazil, found that regardless of the season, either dry or rainy, the MPN of infective propagules was drastically reduced.…”