Mário de Andrade Lira

Caracterização da vegetação de Caatinga e da dieta de novilhos no Sertão de Pernambuco

O objetivo deste trabalho foi avaliar a composicao botânica, a disponibilidade e a qualidade da forragem e da dieta de animais fistulados alimentados na Caatinga, no periodo chuvoso, em Pernambuco. Avaliaram-se a composicao botânica e a disponibilidade de fitomassa dos estratos herbaceo, arbustivo e arboreo, nos meses de marco e junho. A avaliacao da qualidade da forragem foi feita por meio da analise bromatologica, realizada em todos os meses do periodo chuvoso. Foram encontradas 67 especies, das quais 28 herbaceas, 20 arbustivas e 19 arboreas. Destas, 19 foram encontradas na dieta dos animais. A disponibilidade de fitomassa do componente herbaceo variou de 1.369 kg ha-1 de materia seca (MS), em marco, para 452 kg ha-1 de MS em junho. A disponibilidade do estrato arbustivo aproximou-se do herbaceo, enquanto o componente arboreo contribuiu com apenas 178 kg ha-1 de MS. Apesar de a disponibilidade de fitomassa ser relativamente alta, apenas uma pequena porcentagem do material encontrado pode ser considerada como forragem. Foi observada baixa digestibilidade da proteina, provavelmente em consequencia do alto teor em lignina.

Microbiological process in agroforestry systems. A review

Soils around the world are degraded due to inappropriate management practices. There is thus the necessity to find more conservationist agricultural systems. Agroforestry system is an alternative system that helps prevent land degradation while allowing continuing use of land to produce crops and livestock on a sustainable basis. Agroforestry system is a form of sustainable land use that combines trees and shrubs with crops and livestock in ways that increase and diversify farm and forest production while also conserving natural resources. This system enhances organic carbon accumulation in soils by the inclusion of cover crops and permanent vegetation, which is expected to increase the soil microbial biomass. The use of microorganisms aims at improving nutrient availability for plants. Currently, there is an emerging demand to decrease the dependence on chemical fertilizers and achieve sustainable agriculture and agroforestry. Arbuscular mycorrhizal fungi, plant growth-promoting rhizobacteria, and the association of rhizobia with leguminous plants are mutualistic symbioses of high economic importance for increasing agricultural production. The biological nitrogen fixation (BNF) process is an economically attractive and ecologically sound method to reduce external nitrogen input and improve the quality and quantity of internal resources. BNF by associative diazotrophic bacteria is a spontaneous process where soil nitrogen is limited and adequate carbon sources are available. However, the ability of these bacteria to contribute to increased crop yields is only partly a result of BNF. The successful use of legumes is dependent upon appropriate attention to the formation of effective symbioses with root nodule bacteria. An essential component for increasing the use of legumes is the integration of plant breeding and cultivar development, with appropriate research leading to the selection of elite strains of root nodule bacteria. An expansion of the utility of inoculants is also necessary to develop a broad conceptual framework and methodology that is supported by scientific arguments; it is destined to impact assessment of the use of new biological products in agriculture.

Deposição e acúmulo de matéria seca e nutrientes em serapilheira em um bosque de sabiá (Mimosa caesalpiniifolia Benth.)

n Quantification of litter deposition and organic mantle accumulation are important steps on nutrient cycling studies. This study aimed to quantify litter deposition and organic mantle in a sabiAE (Mimosa caesalpiniifolia Benth) woodlot in an experimental farm in the Brazilian northeast region. Twenty 0.50 x 0.50 x 0.15 m wood collectors, to quantify litter deposition, were systematically distributed over the area elevated 30 cm above the soil. Deposited material was collected monthly from October 2000 to September 2001, and separated into leaves, twigs, flowers, pods and mixed portions. Undecomposed organic mantle was randomly sampled nearby collector boxes, to a total of 20 monthly samples, from which a 0.30 x 0.30 m composed sample was collected. The collected material was also hand separated into leaves, twigs, flowers,

Relação entre características morfológicas e produtivas de clones de palma-forrageira

This research evaluated the relationship among the morphological and productive characteristics of clones of cactus forage for identification of those that directly contribute to the production. It was evaluated 50 clones of cactus forage planted five years ago and submitted to the first cut two years before the evaluation. Characteristics of the plant and of the cladode were evaluated and data were analyzed by descriptive characteristics, Pearson correlation and by path analysis of the explanatory independent variables on the dry matter production in t/ha/2 years (main dependent variable). Production varied among clones and it was the highest in clones 8, 782 e 418 whose dry matter production was of 40.8; 18.1 and 12.1 tMS/ha/2 years, respectively. There was a low correlation among almost all the explanatory variables and the production considered main variable, so, association of characteristics was needed. Characteristic height associated with plant width explained better the potential of dry matter production in t/ha/2 years because they presented a high correlation with production (r = 0.71) and the highest direct effect (0.69). Indirect and non destructive selection for production have to be based on higher and larger plants.

Variability and heritability of morphologic characters in elephant grass clones in the Forest Zone in Pernambuco

Esta pesquisa foi realizada para avaliar a variabilidade e herdabilidade de caracteres morfologicos de 54 clones de capim-elefante na Zona da Mata de Pernambuco (tres testemunhas locais e os demais provenientes da RENACE/CNPGL). Utilizou-se delineamento em blocos casualizados com testemunhas adicionais. Foram realizados tres cortes de avaliacao aos 60 dias de crescimento. Houve diferencas significativas para diâmetro de colmo, densidade de perfilhos basais e aereos, largura da folha 3, comprimento da folha 5, porcentagem de lâminas foliares, porcentagem de colmo e relacao lâmina foliar/colmo. Os clones da RENACE sao semelhantes aos tradicionalmente cultivados nas condicoes da Zona da Mata de Pernambuco quanto a maioria dos caracteres morfologicos. A cultivar Pioneiro floresceu precocemente nas condicoes ambientais deste estudo. As caracteristicas numero de perfilhos basais e aereos/metro apresentaram alta herdabilidade, o que evidenciando pouca influencia do ambiente na variabilidade entre clones. Considerando a variabilidade entre os clones da RENACE para numero de perfilhos basais e aereos/metro e relacao folha/colmo e a alta herdabilidade desses caracteres, e possivel obter ganhos geneticos para essas caracteristicas no melhoramento do capim-elefante na regiao da Zona da Mata de Pernambuco.

Variabilidade e herdabilidade de caracteres qualitativos relacionados à qualidade de forragem de clones de capim-elefante na Zona da Mata de Pernambuco

The objective of this research was to evaluate variability and heritability of quantitative traits related to forage quality of 32 clones of elephant grass (three local controls, from Zona da Mata de Pernambuco, and the remaining from RENACE/CNPGL). A complete randomized design was used with additional controls and analyses of variance was applied by using the procedure of families with controls between rows. Evaluation was performed during the dry period, at 60 days of growth. It was observed significant differences among clones for the traits acid detergent of leaf blade and stem organic matter, with means of 34.05 and 78.83%, respectively. In general, heritability of qualitative traits was low, including null values for crude protein and neutral detergent fiber of leaf blade and in vitro digestibility of dry matter of leaf blade and stem. Chemical composition and digestibility of evaluated clones were similar. There are few possibilities of gain in selection for qualitative traits considering the low variability and heritability of the studied characters.

Repetibilidade e respostas de características morfofisiológicas e produtivas de capim-elefante de porte baixo sob pastejo

The objective of this study was to estimate the coefficients of repeatability and determination (R2) and the minimum number of measurements necessary to predict the real value of morphophysiological and yield variables, as well as the responses to sheep-grazing of dwarf elephant grass pasture. The experiment was carried out in a randomized block design with five treatments - Taiwan A-146 2.27, Taiwan A-146 2.37, Taiwan A-146 2.114, Merker Mexico MX 6.31 and Mott - and four replicates, over five grazing cycles, between September 2008 and April 2009. Mean sward height, leaf area index (LAI), light interception (LI), mean leaf angles (MLA), silage accumulation (SA) and silage accumulation rate (SAR) were evaluated. For the variables LAI, IL and mean sward height of plants, in long cycles, only one measurement was necessary (R2 = 80%) to place them among the most predictable characteristics in the evaluation of elephant grass clones. Assessments for SA and SAR need longer experimental periods for greater reliability in the estimation of response variables. In dwarf elephant grass, light interception increases with sward height and LAI.

Comportamento de clones de pennisetum submetidos a períodos de restrição hídrica controlada

The experiment was conducted in a green-house of the Agronomic Institute of Pernambuco, to evaluate Pennisetum sp. clons submitted to different periods of water reposition suppression. The experimental design was completely randomized in a factorial arrangement with four Pennisetum sp. clones and four periods without water reposition (0, 7, 14 and 21 days), with three replicates. Evapotranspiration, dry matter content and production, water use efficiency, average plant height, basal tiller number, water stress symptoms, number of regrowth plants and basal tiller number after the stress were measured. A longer water suppression period affected evapotranspiration more than dry matter production, with water use efficiency being 449 and 591 g of water per g of dry matter for treatments with 21 and 0 days of irrigation suppression, respectively. Seven days without irrigation increased dry matter content from 25.11 to 53.07 and from 29.25 to 46.89 for Australiano and HV241 clons, with no significant difference (p>0.05) for the two other clons. Among the evaluated clons, Australiano and HV241 had the highest dry matter production under moderate water deficit.

Rendimento forrageiro e valor nutritivo de clones de pennisetum sob corte, na zona da mata seca

EnglishThe objective of this work was to verify the MS production and nutritive value of five clones of Pennisetum. The samples were taken from an utile area of 2,0 m2 in each plot. After clipping the forage to standarize, four cuts were performed with 60-d intervals. In each plot, three tillers were oven-dried and grinded for laboratory analysis. The following response variables were determined: dry matter concentration (MS), crude protein (PB), neutral detergent fiber (FDN), acid detergent fiber (FDA), ether extract (EE), mineral matter (MM), in vitro dry matter digestibility (DIVMS), total carbohydrates (CHOT), and non-fibrous carbohydrates (CNF). The evaluated genotypes presented average MS yield of 1.7 and 2.1 t/ha/cut, for leaf blade and stem, respectively. Average nutritive value was 21.1 and 15.1% for MS; 9.1 and 5.3% for PB; 73.2 and 77.7% for FDN; 40.3 and 47.4% for FDA; 9.6 and 11.6% for MM; 1.9 and 0.7% for EE; 56.2 and 56.3% for DIVMS; 79.3 and 82.4% for CHOT; and 11.4 and 9.7% for CNF, in leaf blades and stem, respectively. The clones presented medium to high heritability, similar biomass production and nutritive value, when harvested at 60 days of regrowth in the conditions of the forest zone of Pernambuco. portuguesObjetivou com este trabalho verificar a producao e valor nutritivo de cinco genotipos de Pennisetum (IRI-381, Venezuela, Elefante B, HV-241 e Hexaploide) sob corte na Zona da Mata Seca de Pernambuco. As amostras foram obtidas de uma area util de 2,0 m2, num delineamento em blocos casualizados com 6 repeticoes. Apos o corte de uniformizacao, efetuaram-se quatro cortes a intervalos de 60 dias. Foi tomada uma amostra de tres perfilhos de cada parcela. Foram avaliados os percentuais de materia seca (MS), proteina bruta (PB), fibra em detergente neutro (FDN), fibra em detergente acido (FDA), extrato etereo (EE), materia mineral (MM), digestibilidade in vitro da materia seca (DIVMS) carboidratos totais (CHOT) e carboidratos nao fibrosos (CNF). Os genotipos avaliados apresentaram rendimento medio de MS de lâminas foliares de 1,7 t/ha/corte e de colmos de 2,1 t/ha/corte, nao havendo diferenca entre clones (p>0,05). Nas lâminas foliares e nos colmos, respectivamente, observou-se 21,1 a 15,1% para MS; 9,1 a 5,3% para PB; 73,2 a 77,7% para FDN; 40,3 a 47,4% para FDA; 9,6 a 11,6% para MM; 1,9 a 0,7% para EE; 56,2 a 56,3% para DIVMS; 79,3 a 82,4% para CHOT e 11,4 a 9,7% para CNF. Os clones apresentaram de media a alta herdabilidade e rendimento forrageiro e valor nutritivo semelhantes, quando manejados aos 60 dias de idade nas condicoes da Zona da Mata Seca de Pernambuco.

Dry matter intake and performance of Girolando and Guzerá heifers and Guzerá under supplementation in caatinga, during the rainy season, in Pernambuco, Brazil

To estimate dry matter intake and to evaluate variation on live weight of heifers, an experiment was conducted from March to July 2003, with the following supplementation strategies: no supplementation (control), cottonseed cake (1 kg); spineless cactus (10 kg); spineless cactus + 0.5 kg of cottonseed cake (5 kg). Dry matter intake of native pasture was not affected by supplementation, but it affected total dry matter intake. Intake of total dry matter (DM) differed among breeds with values of 5.44 and 6.75 kg/day, respectively for Guzerat and Girolando breeds. For animal fed cottonseed cake supplementation, total DM intake was higher than in the control group (no supplementation), however, it was similar for those under spineless cactus and cottonseed cake + spinelles cactus supplementation. Daily average body weight gain (517 and 434 g/animal, respectively, for Girolando and Guzerat groups) did not differ among breeds neither was affected by breed o supplementation interaction. However, among strategies of suplementation, values were significantly different and they were 412, 620, 371 and 498 g/animal/day, respectively, for control and cottonseed cake suplementation group; spineless cactus; cottonseed cake + spineless cactus. In Pernambuco semiarid, 1 kg of cottonseed cake supplementation improved daily average weight gain, regardless to breed of the animal during the rainy season.