RCAAP Repository

Eucalypt wood production is associated with a long cutting cycle, wide spacing and specific silvicultural treatments, and allows intercropping with grain and forage producing species. The objective of this study was to evaluate the silvicultural and productive performances of eucalypt under different arrangements in agrosilvipastoral system. Clonally propagated E. camaldulensis x E. urophylla hybrid was planted in the Brazilian savanna. The plants were intercropped with rice (first year of planting), soybean (second year) and Brachiaria brizantha pasture (following years). The experimental design was randomized blocks with 11 treatments (11 arrangements of eucalypt) and five replications, with plots splitted along of the time (18, 27, 38 and 51 months after planting). There was no treatment effect in wood volume of eucalypt trees until 18 months after planting. Wood volume was greater in the larger spacings 27 months after planting. From month 38 on, diameter at breast height showed to be positively affected by the available area to each tree. Until the fourth year, the arrangements 3.33 m x 2 m, 3.33 m x 3 m and 5 m x 2 m are indicated to quantity production wood, while 10 m x 3 m e 10 m x 4 m are indicated to produce major size wood.

The Clean Development Mechanism (CDM), generated a global debate about the silviculture and agrossilviculture potential as an elegible project-based activities reducing GHG emissions. This study aimed to estimate the amount of carbon and biomass storage in a mixed silvopastoral system with Eucalyptus grandis and Acacia mangium at the Zona da Mata of Minas Gerais State. The system had a plant density of 105 plants per hectare which was 60 eucalyptus and 45 acacia. The stem volume of 10 year old trees was assessed using alometric equations and the residual mean pasture biomass was quantified. For the eucalyuptus plants, the estimative of biomass and carbon were 24.8 Mg ha-1 and 11.17 Mg.ha-1, respectively, while those for acacia were 6.94 Mg.ha-1 and 3.12 Mg.ha-1. The total amounts was 31.74 Mg.ha-1 of biomass and 14.29 Mg.ha-1 of carbon. It was estimated that the pasture, considering only the residues of pasturing, accumulated 1.28 Mg.ha-1 of biomass and 0.58 Mg.ha-1 of carbon.

The agronomic traits and nutritive value of Brachiaria decumbens pasture were evaluated under three shade percentages (0.29% and 45%), provided by leguminous trees (Acacia angustissima, A. mangium, A. auriculiformis, Albizia lebbek e Gliricidia sepium), during winter, spring and summer seasons. The experimental design was randomized blocks, with three replications. The forage mass was positively influenced by shading, in spring and summer seasons. In winter, the higher forage mass was observed in full sunlight condition. The values of crude protein increased in spring with shading, but did not vary with shade percentage in winter and summer seasons. The crude protein quantity per area, obtained by product between forage mass and crude protein concentration, was higher under more intensive shading, in spring and summer seasons. Fiber detergent neutral content and in vitro dry matter digestibility did not present consistent variation with shading, in function of the strong interaction between this variable and season of the year.

An economic viability analysis was performed for different eucalypt wood production systems (Eucalyptus grandis Hill ex. Maiden) in two rural properties located in Alegrete County, RS. The traditional pasture system was compared with two other alternative systems, one of them represented by a pasture land converted to homogeneous eucalypt plantation by using two plant densities (2,222 and 1,111 trees.ha-1) and the other represented by a silvopastoral system containing 1,000 and 500 trees.ha-1. The results were analyzed by determining the Internal Retuurn Rate (IRR) and comparing it to the Minimum Attractive Rate (MAR). The alternatives with and without land value were evaluated taking into account the wood price variation (gain and lost of 5%) and the wood yield (gain and lost of 10%). Considering the land value, all alternatives showed that the IRR was lower than the MAR (3.72%). The sensibility analysis showed that when price and yield of the wood had their values increased, for the majority of alternatives considering the practice of thinning, the IRR was higher than the MAR, except to silvopastoral system containing 500 trees.ha-1. The conclusion was that, the forest component implementation is economically viable for the land owner, except by the fact that it is necessary to disregard the land value in this approach.

A silvopastoral study consisting of black wattle (Acacia mearnsii De Wild) and tropical perennial grasses was developed at the Fepagro Research Unity in Tupanciretã, RS, in collaboration with Seta Group, from October 1995 until May 2003, with the objective of evaluating trees and animal (beef cattle) performances. The experiment was a bifactorial completely randomized design (forage specie and arboreal density) with two replications. The forage species assessed (FS) were anonni grass (Eragrostis plana), signal grass (Brachiaria brizantha) and gatton panic (Panicum maximum cv. Gatton) in the first four years, and gatton panic, aruana grass (Panicum maximum cv. Aruana) and pangola grass (Digitaria diversinervis) in the remaining years. Trees densities (TD) tested were of 1,667; 1,000; 833 and 500 trees.ha-1. The highest wood production was observed at TD 1,667 trees.ha-1, although it was not different from that for 1,000 trees.ha-1 from the fifth year on. The animal production under arboreal density 833 and 500 trees.ha-1 was 229 e 223 kg.ha-1 of liveweight gain, respectively. At seven years of cultivation of black wattle the wood production were 166; 143; 86 and 51 m3/ha-1, respectively, under arboreal density of 1,667; 1,000; 833 and 500 trees.ha-1. To achieve of an equilibrium between trees and animal production, this study showed that silvopastoral systems with 1,000 and 833 trees.ha-1 are viable alternatives for farmers.

The silvopastoral systems (SPSs) have been considered promising to integrate tree crops in livestock production systems and reclain large areas of degraded pastures of the Brazilian Amazon. They are used on small scale by innovative farmers, the SPSs lack a scientific basis to provide technical subsidies to its wider use, especially when it comes to justifying the economic viability of these systems. The objective of this study was to analyze the economical viability of SPSs, established in farms areas used by producers in the Northeast State of Para and comparing to the traditional monoculture. The systems are composed basically by parica (Schizolobium parahyba var. amazonicum (Huber ex Ducke) Barneby) or teak (Tectona grandis L. F.) in kikuyu grass (Brachiaria humidicola (Rendle) Schweick) under cattle grazing. The analysis of economical viability was realized by the indicators: net present value (NPV), internal rate of return (IRR) and benefit-cost ratio (Rb/c), considering the four models of SPSs and monoculture of parica and teak. The systems composed by teak are economically more attractive than that with paricá, and among all silvopastures arrangements, when the livestock cattle was owned himself were considered better viability than the systems in monoculture or in which the animal incorporation was rental by pasture.

Proposing economic and ecological land-use alternatives has been a great challenge for agricultural research in the Brazilian Amazon. The silvopastoral systems (SPS) are promising to integrate trees in the livestock production system and reclaim degraded pastures in the Amazon region. In Municipality of Paragominas, State of Pará, nine SPS composed by combination of three tree species (Schizolobium amazonicum, Bagassa guianensis and Eucalyptus tereticornis), planted in 6 m-lane, spaced by 12 m – and three pastures (Brachiaria brizantha, B. humidicola and Panicum maximum / dictioneura B. dictyoneura), planted in the inter-lane space. Steers grazed the one-hectare experimental parcels simulating a rotational grazing system with 14 days - grazing period and 42 days – rest period, and was evaluated during August 1990 to November 1991. From the tree and pasture management point of view, the more promising silvopastoral combinations were, respectively, S. amazonicum - B. brizantha and E. tereticornis - B. brizantha.

Agroforestry research in the Brazilian Amazon began in the eighties by Agricultural Research Brazilian Enterprise (Embrapa), Executive Commission of Cacao Plantation (CEPLAC), and the National Institute of Amazonian Research (Inpa) by the Agronomic Science Research Coordination (CPCA). Evaluation of literature on agroforestry systems can identify lacking areas of information or grouping them into knowledge area. Thus, it is possible to extract lessons to be used for planning and executing public polices. This paper analyzed the literature on agroforestry systems, in the Brazilian Amazon, from 1980 to 2005. The bibliography survey was based on database of Embrapa Eastern Amazon as well as on the Agricultural Research Data Base (BDPAWeb) through the search expression [*Amazon and sist* and agriculture* and agrossi*]. The literature was classified by year, responsible institution, author, local implementation, and use of trees. A total of 460 references were classified. The chronological analysis showed that the Brazilian Congress of Agroforestry System (CBSAF) contributed to increase the scientific production. In general, agroforestry research needs a long time for validation. However, projection of scenarios by modeling could shortening time. We observed a gap in modeling of systems. Therefore, it is necessary to develop this issue seeking to obtain more dynamic and solid progresses in the agroforestry system research.

Although researches related to silvopastoral systems have been initiated many years ago in Brazil, there are few informations generated until now. The advantages from a silvopastoral system are inumerous and well recognized. By the fact of being a technique of land using capable of recovering several disturbed ecosystems, the silvopastoral systems by the integration of agricultural, cattle, and silvicultural activities represent a technology that can achieve higher sustainability than the traditional systems as the monocultures. Today, research centers in Brazil dedicate great attention to agrossilvopastoral systems. The government of Minas Gerais State, through the extension offices is promoting the agricultural, cattle and silvicultural practices in an integrated process of soil occupation. Even with good level of knowledge about annual crops, trees components, an example eucalyptus, and forage grasses tolerant to lower light intensity, it is necessary a better knowledge of the management of understory under the effects of grazing.

The selection of adapted tree species is fundamental for the success of silvopastoral systems. The present study aimed to evaluate the initial development of native trees seedlings planted on pastureland chosen by their economic value and nitrogen retrieval. The seedlings were planted in strips containing three lines. Between each strip there was an area of 15 m with pasture. From the measurements of tree height, diameter at the base, damage by insects or by diseases, it was reported the best performances for canafístula (Peltophorum dubium), pau-jacaré (Piptadenia gonoacantha), mutambo (Guazuma ulmifolia) and capixingui (Croton floribundus). Ipê-felpudo (Zeyheria tuberculosa) showed the worst performance of all under the conditions evaluated. Survival rate in eleven months for pau-jacaré was under 50%.

The objective of this research was to study the relationship between the DBH with crown diameter,stump diameter and inside bark diameter at breast height of Araucaria angustifólia (Bert.) O, Kuntze. The data from the mentioned variables came from 162 Araucaria distributed in the whole amplitude of diameter at breast height in a Mixed Ombrophylous Forest fragment with 15,24 hectares located at the Curitiba urban region, State of Parana, Brazil. All the fitted relationships resulted in predictive equations with good values for the Schlaegel Index, Syx%, value of F and value of ρ for the coefficients, as well as good performance in the graphic analysis of residual. doi: 10.4336/2010.pfb.30.64.369

The cupuaçuzeiro (Theobroma grandiflorum), species native from the Amazon region, has been domesticated presenting a broad genetic variability, and thus favorable conditions for establishing of strategies to breeding and genetic conservation. The aim of this work was to evaluate 36 half-sib progenies of Theobroma grandiflorum obtained from a stratified mass selection in farmers areas based on primary components of yield. The experiment for selection of elite progenies was set up in a randomized complete block design with three replications and four plants per plot. The fruit traits (length and width, in cm) and components of production (average weight of fruit/plant; average weight of pulp with seeds/plant and average weight of pulp/plant, in g) were evaluated. The data were analyzed through the methodology of REML/BLUP using the Selegen software. Analysis of grouping was performed using the matrix of genetic euclidean distances and Mahalanobis. The experimental population allowed the selection of superior parents for formation of base population to be used in the genetic improvement of cupuaçu. Among the 36 analyzed lineages only the genotypes 9, 10 and 18 showed genetic divergence and they can be recommended with some lineage of group 1 that demonstrates agronomic superiority to form base population of experimental clones with high genetic dissimilarity.doi: 10.4336/2011.pfb.31.66.123

Vegetative propagation of imbuya (Ocotea porosa) and the germination process of its seeds is slow, justifying tetrazolium test, that is faster for verifying viability of seeds. Seeds of Colombo (PR)  native trees were collected and treated with 0.1 %, 0.3 % and 0.5 % tetrazolium solutions for one and two hours, presenting percentual  variation associated with the different treatments. No statistical significant differences were observed among different treatments. Viable seeds varied among 50 % and 85 %. Tetrazolium 0.5 % for one hour was suggested as the minimum for verifying viability of imbuya seeds.

Imbuya (Ocotea porosa Nees et Martius ex. Nees, Lauraceae) is a species under extinction of the Mixed Ombrophylous Forest, whose wood owns high economic value. The objective of this work was to discuss precocious individual genetic selection utilizying Selegen REML/BLUP software in germoplasm of Colombo, PR, Canoinhas and Caçador, SC, populations. Results showed that 1182 selected genotypes (42,9 %) were from Colombo, 1004 (36,4 %) genotypes were from Canoinhas and 572 (20,7 %) from Caçador, totalyzing 2758 selected genotypes. Estimates of variance components showed that additive genetic variance within provenances (Va=6,62) is higher than variance among provenances (Vproc.=1,33), indicating the possibility of predominance of alogamy in the studied populations. Individual heritability in narrow sense in the block (h2a), that is, from additive effects,was 0.29 ± 0.04. Individual genetic variance coefficient (CVgi) was 18,72. Ranking of 50 superior genotypes showed a genetic gain from 5.66 cm to 8.72 cm, with estimates of averages in the next  generation varying from 19.04 cm to 22.45 cm (increment ranging from 41.9 % to 63.46 %). Colombo provenance contributed with 56 % of 50 superior genotypes, Canoinhas with 40 % and Caçador with 4%.

It is proposed a breeding strategy for eucalypt, which congregates in an individual desirable traits belonging to different species and capture the heterosis for growth, stemming from several pair of species of known heterotic behavior. Such strategy relies on obtaining two synthetic multi species populations and posterior reciprocal recurrent selection (RRS) between them. It is called reciprocal recurrent selection between synthetic multi species populations (RRS-SMSP) and improves the traits drought, disease resistance, volume, density, yield and lignin content. Options for making the synthetic multi species populations are presented. The RRSSMSP is suitable for applying the genomic selection.

The objective of this research was to test and select mathematics models for estimating total heigh (ht) and bole high (hb), as a function of DBH, as well as, to establish the dendrometric relationship  between ht/hb. The data came from measurements of diameters (DBH), total height and bole height of all Araucaria angustifolia trees from an Ombrophylous Mix Forest fragment of 15,24 ha situated in the Botanical Garden Campus of the UFPR, Curitiba-PR, Brazil. Thirteen  models were tested, including arithmetic, logarithmic and nonlinear  models, such as Chapman-Richards and Mitschertich or monomolecular adapted; the nonlinear models were fitted by the Levenberg-Marquart algorithm. The statistic criteria for selecting the best models were the graphic analysis of residuals, Standard error of estimate in percentage (Syx%) and adjusted determination coefficient (R2 aj). The R2 aj were very low for all fitted models, characterizing an advanced and asymptotic stage of the species under study. The best equation for estimating ht was that one proposed by Stoffels & Van Soest, and for hf the Curtis equation in its logarithmic form, chosen due to its statistics values and easy utilization. The adjusted linear equation to estimate total height as a function of bole height presented R2 aj = 0.88 and Syx% = 5 %, characterizing a strong relationship between these two variables.

The objectives of this research were: to develop equations to estimate the stem and firewood volume of bracatinga (Mimosa scabrella Benth.); to evaluate the accuracy of the estimates having as a  comparator the true volumes obtained by the xylometer method; to  test the validity of Ahrens' (1981) published equation. In bracatinga stands, 384 trees were measured until a minimum diameter of 4 cm at the small end. The validation set was composed by 55 trees measured by the xylometer. The ² (chi-square), aggregated difference test, standard error of estimation, average error and graphical distribution  of the residuals were used on validation process. The best equation obtained for the stem was provided by Schumacher-Hall model. For  firewood, data were stratified, forming one set of trees with DBH < 6 cm and other with DBH 6 cm. The first set was best modeled using Parabolic model, while the second one performed better applying  Schumacher-Hall model. The validated equations resulted in ² values not significant at the level of 5% and no visible tendencies along the collected DBH extent. Ahrens' (1981) equation also had a not significant ² value at 5%, but presented a strong underestimate along all its DBH extent.

It was evaluated the effect of different residue management systems in the plant nutrition status, nutrient contents in the litter and litter biomass yield, on Eucalyptus grandis plantation. Samples were taken on four residue management systems: (i) removal of all residues from previous harvesting and NPK fertilization; (ii) maintenance of all residues on soil surface and NPK fertilization; (iii) removal all at bark  and commercial-size crop stems over 3 cm diameter and NPK fertilization; (iv) removal of all residues from previous harvesting, NPK fertilization and addition of industrial waste (15 t.ha-1 of pulp and paper sludge, C:N ratio 25:1 and 4 t.ha-1 of wood ash, C:N ratio 30:1). Results showed that the maintenance of the forest residues on site improved the nutritional status of trees and increased productivity. Addition of industrial waste allowed expressive increase of Eucalyptus sp growth. Possible excesses of Ca from the industrial waste used  should be corrected, to avoid nutritional unbalance in the trees; independent of the treatment used, the amounts of K added to the soil are not enough to maintain appropriate tree nutritional status. Greater amounts of K should be added to correct soil nutritional deficiencies on this element. 

The aim of this work was to measure the effect of ash, collected from  the boiler of a pulp mill and applied in doses equivalent to 0, 10, 20, 40 and 80 t.ha-1 on the chemical characteristics of the soil and on the development and absorption of nutrients for Pinus taeda L. seedling potted with CAMBISSOLO Humico from the 0-20 cm layer in Piraí do Sul, PR. Portions of the soil were placed in pots and aliquots of each treatment were applied to the first 0-10 cm layer after filled the pots with 20 cm of soil. Needles and soil (0-10, 10-20 and 20-30 cm layers) were analyzed. The height, diameter and dried biomass of aerial part, the root - MSR and total were evaluated. The application of ash reduced the acidity and the concentration of Al, and increased the concentration of Ca, Mg, K, P, with more pronounced effects in the layer of 0-10 cm; there was no effect of treatment in the development of seedlings; and the concentration of Cu in needles was declined with increasing doses of ash.

Black-wattle growth is different on soils with distinct characteristics. To evaluate this influence, plant growth and wood production variables were quantified on black wattle growing on five soil classes with different morphological, physical and chemical characteristics, on SETA S.A. commercial plantation at seven years of age, on Butiá County, RS. It was measured the black wattle growth on the following soil classes Argissolo Vermelho (Alfisol), Argissolo Vermelho-Amarelo (Alfisol), Cambissolo (Inceptisol), Neossolo Litólico (Entisol) e Neossolo Regolítico (Entisol). Soil chemical and texture analyses were performed on surface and subsurface horizons, and physical analyses, just on soil surface horizon. On plants, it was measured DBH, total height, bark thickness and estimated the wood volume. On both Alfisols (Red and Red Yellow) and on Inceptisol, that presented higher nutrient content and effective soil depth, wood production was 30 % greater than on both Entisols, that were shallower and with less appropriate chemical characteristics.