INFLUÊNCIA DO SUBSTRATO E INOCULAÇÃO MICORRÍZICA NA PRODUÇÃO DE MUDAS DE Colubrina glandulosa Perkins

A revegetação de áreas desmatadas de Mata Atlântica pode ser realizada com mudas de espécies florestais nativas inoculadas com fungos micorrízicos arbusculares (FMA). Este trabalho objetivou avaliar o efeito de diferentes substratos, na ausência/presença de inoculação com FMA, sobre o crescimento e conteúdo nutricional de mudas de Colubrina glandulosa Perkins. As mudas foram produzidas em tubetes em casa de vegetação. O delineamento experimental foi inteiramente casualizado, com 12 repetições/tratamento e oito tratamentos: T1 (20% esterco bovino + 80% terra), T2 (20% esterco bovino + 80% terra + FMA), T3 (20% esterco bovino + 60% terra + 20% areia), T4 (20% esterco bovino + 60% terra + 20% areia + FMA), T5 (20% esterco bovino + 60% terra + 20% vermiculita), T6 (20% esterco bovino + 60% terra + 20% vermiculita + FMA), T7 (20% esterco bovino + 60% terra + 10% areia + 10% vermiculita) e T8 (20% esterco bovino + 60% terra + 10% areia + 10% vermiculita + FMA). Aos 30, 65, 93 e 115 dias após a instalação do experimento, avaliou-se a altura (H) e diâmetro do coleto (DC). Aos 115 dias, avaliou-se a massa de matéria seca da parte aérea (MSPA) e raiz (MSR), razão MSPA/MSR, taxa de colonização micorrízica da raiz (%COLRAIZ), Índice de Qualidade de Dickson (IQD), conteúdo de nutrientes (N, P, K) na parte aérea e raiz, e eficiência de absorção de nutrientes (N, P, K). Concluiu-se que o T8 é o mais recomendado, pois proporcionou a produção de mudas com elevados valores para a maioria das variáveis de crescimento e nutrição analisadas. Palavras chave: fungos micorrízicos arbusculares, Mata Atlântica, recuperação de áreas degradadas. AbstractEffects of substrate and mycorrhizal inoculation on the production of seedlings of Colubrina glandulosa Perkins. Revegetation of deforested Atlantic Forest areas can be carried out with seedlings of native tree species inoculated with arbuscular mycorrhizal fungi (AMF). This study aimed to evaluate the effect of different substrates in the absence/presence of AMF inoculation on growth and nutritional content of Colubrina glandulosa Perkins seedlings. The seedlings were grown in plastic pots under greenhouse conditions. The experimental design was completely randomized with 12 repetitions/treatment and eight treatments: T1 (20% cattle manure + 80% soil horizon), T2 (20% cattle manure + 80% soil horizon + AMF), T3 (20% cattle manure + 80% soil horizon + 20% sand), T4 (20% cattle manure + 80% soil horizon + 20% sand + AMF), T5 (20% cattle manure + 60% soil horizon + 20% vermiculite), T6 (20% cattle manure + 60% soil horizon + 20% vermiculite + AMF), T7 (60% soil horizon A + 20% cattle manure + 10% sand + 10% vermiculite) e T8 (60% soil horizon A + 20% cattle manure + 10% sand + 10% vermiculite + AMF). At 30, 65, 93 and 115 days after the beginning of the experiment, we evaluated the height (H) and collar diameter (DC). At 115 days, we evaluated the dry matter of shoot (MSPA) and root (MSR), MSPA/MSR ratio, rate of roots colonization by mycorrhiza (% COLRAIZ), quality index of Dickson (IQD), nutrient content (N, P, K) in the shoot and root, besides uptake efficiency of nutrients (N, P, K). We recommend the treatment T8 because it provided the production of seedlings with high values of most of the growth and nutrition variables analyzed.            Key words: abuscular mycorrhizal fungi, Atlantic Forest, land reclamation

CHARACTERIZATION AND USE OF SUBSTRATES COMPOSED OF ORGANIC WASTE IN THE PRODUCTION OF Colubrina glandulosa PERKINS SEEDLINGS

Urban organic waste has been gaining prominence in the composition of substrates, as it is a source of natural nutrients and a sustainable alternative to mitigate environmental impacts caused by improper waste disposal. The aim of this study was to characterize chemically and physically substrates based on organic waste and to evaluate the development of Colubrina glandulosa seedlings using composted urban tree pruning waste. Treatments consisted of different proportions of organic compost (CP), soil from the A horizon (SAH), aged manure (BM) and vermiculite, kept in tubes (Citropote®) with volume of 1.7 L. C/N ratio, water holding capacity (10 hPa), electrical conductivity, macroporosity, microporosity and total porosity of substrates before their use were determined. Substrate fertility analyses were carried out before and after seedling production. During the development of the seedlings, height (H) and stem diameter (SD) were measured at 60, 90 and 120 days. At 90 and 120 days, the seedlings were divided into shoots and roots to determine the dry mass of each compartment, Dickson quality index (DQI) and contents of nutrients (N, P, K, Ca and Mg). After the analysis of the results, it can be observed that the treatments with high proportions of CP had better physical characteristics, but also showed chemical limitation in the development of the seedlings. Treatments based on BM, SAH and lower proportion of CP had the highest average results for H, SD, H/SD ratio and DQI.

Soil organic matter fractions, chemical attributes and aggregation under forestry and agricultural systems

The aim of this work was to evaluate the influence of the conversion of forest systems to agricultural systems in the organic matter compartments, aggregation and soil chemical attributes, in the Atlantic Forest. The evaluated systems were: annual crop (ACr); perennial agriculture (PAg); pasture; and secondary forest early (SFES), medium (SFMS), and advanced stage (SFAS). Soil samples were collected at the layer of 0-5 cm depth and quantified the total organic carbon (TOC), C of humic substances, oxidizable C, granulometric fractions of soil organic matter (SOM), soil chemical attributes, soil aggregation and glomalin-related soil protein (GRSP-total and GRSP-easily extractable) in different aggregate classes. It was observed a reduction of the TOC, particulate organic carbon (POC), humic substances and oxidizable C in the PAg and ACr areas comparing to pasture and forest systems. Moreover, the pH values increased whereas P content decreased in comparison with SFAS. As for aggregation, the PAg and the ACr decreased by around 35% and 20% the mean weight diameter of aggregates, respectively, compared to the average values found in the forestry systems, and 34% and 45%, respectively in relation to pasture. In general, GRSP-total were reduced by agriculture. Thus, it appears that the agriculture which has been practiced is altering negatively the soil chemical, physical and biological attributes.The aim of this work was to evaluate the influence of the conversion of forest systems to agricultural systems in the organic matter compartments, aggregation and soil chemical attributes, in the Atlantic Forest. The evaluated systems were: annual crop (ACr); perennial agriculture (PAg); pasture; and secondary forest early (SFES), medium (SFMS), and advanced stage (SFAS). Soil samples were collected at the layer of 0-5 cm depth and quantified the total organic carbon (TOC), C of humic substances, oxidizable C, granulometric fractions of soil organic matter (SOM), soil chemical attributes, soil aggregation and glomalin-related soil protein (GRSP-total and GRSP-easily extractable) in different aggregate classes. It was observed a reduction of the TOC, particulate organic carbon (POC), humic substances and oxidizable C in the PAg and ACr areas comparing to pasture and forest systems. Moreover, the pH values increased whereas P content decreased in comparison with SFAS. As for aggregation, the PAg and the ACr decreased by around 35% and 20% the mean weight diameter of aggregates, respectively, compared to the average values found in the forestry systems, and 34% and 45%, respectively in relation to pasture. In general, GRSP-total were reduced by agriculture. Thus, it appears that the agriculture which has been practiced is altering negatively the soil chemical, physical and biological attributes

Dependency and Response of Apuleia leiocarpa to Inoculation with Different Species of Arbuscular Mycorrhizal Fungi

ABSTRACT Inoculation with arbuscular mycorrhizal fungi (AMF) is a strategy to improve the efficiency of forest plantations, reducing costs and increasing the survival of plant species. The objective of this study was to assess the response and mycorrhizal dependency of seedlings of the forest species Apuleia leiocarpa (Vogel) J.F. Macbr to inoculation with AMF. The experiment was conducted in a completely randomized design using a 5 × 5 factorial arrangement with six replications. The treatments consisted of combinations of five P rates (0, 24, 71, 213, and 650 mg kg-1) with five types of inoculations with AMF (inoculation with the fungi Rhizophagus clarus, Gigaspora margarita, Dentiscutata heterogama, inoculation with an AMF mix of these three species, and a treatment without inoculation). The A. leiocarpa showed the highest biomass accumulations in inoculation with D. hetorogama combined with the P rates of 213 and 650 mg kg-1, and in the AMF mix combined with the P rates of 71, 213, and 650 kg-1. Biomass accumulation showed a linear, positive response to inoculation with D. heterogama combined with the different P rates, and a positive square root fit to inoculation with the AMF mix. The plants inoculated with G. margarita had no significant biomass accumulation. The plant species had a positive response to inoculation with R. clarus combined with the lowest P rates; however, it had a negative response to combination with the highest P rate (650 mg kg-1). The relative benefit of inoculation with these fungi was more than 100 % in most treatments, showing the high mycorrhizal dependency of A. leiocarpa and the nutritional benefit of AMF inoculation for this species. However, this response is dependent on the fungus species that colonize the plant roots. The best combination between fungus and P rate was inoculation with the AMF mix combined with the P rate of 71 mg kg-1

Soil organic matter fractions, chemical attributes and aggregation under forestry and agricultural systems

The aim of this work was to evaluate the influence of the conversion of forest systems to agricultural systems in the organic matter compartments, aggregation and soil chemical attributes, in the Atlantic Forest. The evaluated systems were: annual crop (ACr); perennial agriculture (PAg); pasture; and secondary forest early (SFES), medium (SFMS), and advanced stage (SFAS). Soil samples were collected at the layer of 0-5 cm depth and quantified the total organic carbon (TOC), C of humic substances, oxidizable C, granulometric fractions of soil organic matter (SOM), soil chemical attributes, soil aggregation and glomalin-related soil protein (GRSP-total and GRSP-easily extractable) in different aggregate classes. It was observed a reduction of the TOC, particulate organic carbon (POC), humic substances and oxidizable C in the PAg and ACr areas comparing to pasture and forest systems. Moreover, the pH values increased whereas P content decreased in comparison with SFAS. As for aggregation, the PAg and the ACr decreased by around 35% and 20% the mean weight diameter of aggregates, respectively, compared to the average values found in the forestry systems, and 34% and 45%, respectively in relation to pasture. In general, GRSP-total were reduced by agriculture. Thus, it appears that the agriculture which has been practiced is altering negatively the soil chemical, physical and biological attributes