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A exploração mineral é considerada uma das principais ações antrópicas que causam a poluição do solo com metais, dentre os quais se encontra o manganês (Mn), que quando em excesso pode causar sintomas de toxidez, inibir o crescimento das plantas e causar alterações nas comunidades vegetais. Objetivou-se avaliar os efeitos dos fungos micorrízicos arbusculares (FMA) na tolerância da espécie Mimosa caesalpiniaefolia Benth. ao substrato degradado pelo rejeito da mineração de Mn e mata preservada. O delineamento experimental foi inteiramente casualizado, em arranjo fatorial 2 x 4, considerando-se: i) dois tipos de substrato (degradado pelo rejeito da mineração de Mn e mata preservada); ii) quatro tratamentos de inoculação com FMA (controle não inoculado, Rhizophagus clarus, Claroideoglomus etunicatum e Mix) com quatro repetições. Aos 60 dias após o transplantio, as variáveis analisadas foram: massa da matéria seca da parte aérea e raiz, densidade de esporos, colonização micorrízica, teor de N e P na parte aérea, teor de Mn na parte aérea e raiz e o fator de translocação de Mn. A inoculação com FMA influencia de forma positiva no aumento da massa da matéria seca da parte aérea e raiz, bem como na tolerância da espécie M. caesalpiniaefolia Benth ao Mn. A espécie vegetal apresenta colonização micorrízica mesmo sob condições de baixa densidade de esporos no substrato com elevado teor de Mn. M. caesalpiniaefolia Benth atua como fitoestabilizadora em áreas degradadas pela mineração de Mn, independente da inoculação com FMA

ABSTRACT: Our objective was to evaluate the morphological pattern of colonization by arbuscular mycorrhizal fungi (AMF) as well as to study the microbiological activity of the soil on family farms where Barbados cherry was cultivated. Soil and root samples were selected from four areas in the municipality of Maranguape-CE where Barbados cherry was grown, which were named according to the age of plants in the following manner: A1-3, A2-3, and A3-3 (3 years), and A4-2 (2 years). After sampling, the arbuscular mycorrhizal colonization, morphological colonization pattern, basal soil respiration (SBR), and density of mycorrhizal spores (DS) were analyzed. The Paris-type morphological pattern was predominant in the root system of Barbados cherry; the affinity of this pattern in the culture was clear. Time of installation and management of Barbados cherry orchards in family farming areas promoted reduction in SBR. P levels in the soil may have negatively influenced root colonization and density of mycorrhizal spores.

In order to determine the effect of organic fertilizer on growth of seedlings of melon inoculated with arbuscular mycorrhizal fungi (AMF), an experiment was conducted under greenhouse conditions. The experimental design adopted was a completely randomized design with four treatments and four replications. Treatments consisted of melon plants cultivated on sterile and non sterile soil in the presence or absence of organic compost. The melon seeds were germinated in trays containing substrate formed by 70% of Soil + 30% of green coconut powder, and the mycorrhizal inoculation used a mixture of the species Glomus clarum and Glomus intraradices, applied at the time of sowing. The seedlings with the first definitive sheet were transplanted into pots with sterile or non sterile soil, fertilized or not with organic compost. After 30 days from transplanting plants were harvested for determining the weight of fresh and dry shoot, stem diameter, arbuscular mycorrhizal colonization and content of macro and micronutrients. Organic compost addition did not influence arbuscular mycorrhizal activity and also increased shoot dry weight. AMF colonization of roots showed influence on macro (N, P and Ca) and micronutrients (Fe and Mn) shoot content on soil sterile with organic compost.

This paper has evaluated the alterations in the number of spores of arbuscular mycorrhizal fungi (AMF) and enzymatic activity in soil under cultivation of banana trees in Chapada of Apodi. The hypothesis was tested that the agricultural use causes environmental alterations that they reduce the presence of population of AMF and the microbial activity. An area was selected under cultivation of banana trees (Farm Frutacor) and its control (natural vegetation). Four soil samples were collected in three depths in which analyses were accomplished, the number of spores of AMF by Gerdemann and Nicholson (1964) and enzymatic activity: acid phosphatase, arylsulphatase and b-glucosidase by Tabatabai, (1994). The number of spores of AMF show values decreasing with the rise in depth in area cultivated. The activity of the arylsulphatase and acid phosphatase were stimulated by the competition of the anions H2PO4- and SO4- for the same ranches of adsorption in the colloids of the soil. For b-glucosidase, there was a larger activity in the cultivated area, influenced by the amount and quality of the vegetable residue. The enzymatic activity evidences a difficulty of establishing correlations between the biochemistry and chemistry of the soil in area where the entrance of nutrients is high.

This work had for objective to test the coconut dust as one of the components of the substratum recommended in the production of seedlings of green pepper (Capsicum annuum L.) and that the inoculation with arbuscular mychorrizal fungi (AMF) it turns the most efficient plant in the absorption of nutrients, especially the phosphorus. A Yellow Red Argissolo was used, the substrata dust dry coconut and dust green coconut. The plants had been inoculated by AMF (Glomus clarum, Glomus intraradices and margarita Gigaspora). The experiment was lead per 45 days, the plants had been supplied weekly with exempt nutritional solution of P and to the end collected and submitted to the analyses of: dry mass of the aerial part, leaf number, height of the plant, diameter of caule, contend of macronutrient and micronutrient of the aerial part of plant. The delineation was of blocks casualizados with eighteen treatments and four repetitions. The results had demonstrated that10% dust dry coconut the seedlings of green pepper presented better results in mass dries of the aerial part, height, number of leves and diameter of caule.

In agriculture practiced in Brazil, the branch of the horticulture is one of the prominences, in production and in exportation, being melon one of the more produced fruits, especially in Brazil¿s northeast. In this context, the use of a good quality substrate is essential for the development of the plants. In this study it was evaluated the growth of melon seedlings and the role of Arbuscular Mycorrhizal Fungi (AMF),Glomus clarum, associated to the use of coconut dust, as an alternative substrate, at 100, 80, 60, 40, 20, 10 and 0% concentrations, as a soil mixture (grayish Argissol). The plants were cultivated under greenhouse conditions and, at the end of a 35 days period, were analyzed the diameter of the stem, number of leaves, height of plants, shoot dry weight, microbial biomass carbon content, basal soil respiration, metabolic quotient, colonization with AMF and shoot nutrient content (N, P, K, Ca and Mg). It was observed that 100% and 80% concentration of coconut dust were the more restrictive treatments for plant development. Microbial carbon and mycorrhizal colonization were higher when the substrate was composed by 10 and 20% of coconut dust. The basal soil respiration and the metabolic quotient (2,07) were higher when 100% coconut dust was used, while the smallest value (0, 96) was found in treatment without coconut dust. The use of concentrations higher than 40% of coconut dust decreased AMF activity and growth of the melon plants.