• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 58
  • 25
  • 3
  • 2
  • 1
  • Tagged with
  • 93
  • 93
  • 53
  • 28
  • 27
  • 22
  • 21
  • 21
  • 20
  • 19
  • 19
  • 19
  • 18
  • 13
  • 12
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Influ?ncia do manejo da palhada de aveia-preta e tremo?o-branco sobre a fauna invertebrada do solo em ambiente de montanha / Influence of the management of black oats and lupines albus straw on the invertebrate fauna of the soil in mountain environment

Antunes, Tayana Galv?o Sceiffer de Paula 31 May 2016 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-07-26T16:23:58Z No. of bitstreams: 1 2016 - Tayana Galv?o Scheiffer de Paula Antunes.pdf: 886909 bytes, checksum: 3d81bdb995e369056c9a96e210803d4c (MD5) / Made available in DSpace on 2017-07-26T16:23:58Z (GMT). No. of bitstreams: 1 2016 - Tayana Galv?o Scheiffer de Paula Antunes.pdf: 886909 bytes, checksum: 3d81bdb995e369056c9a96e210803d4c (MD5) Previous issue date: 2016-05-31 / Aiming to obtain information to support the biodiversity management that enable sustainable production systems and ensure the quality of natural resources, this study contribute to increasing agricultural productivity based on the use of green manure in a sustainable manner, aiming to evaluate the behavior of winter green manures lupines albus, black oats and the consortium between those two in mountain environment, and the influence of the herbicide decomposition rate of straws from these plants and diversity and abundance of soil fauna. The experiment was conducted in the area of EscolaT?cnicaAgr?colaEstadualRei Alberto I, located in the Watershed Barrac?o dos Mendes, Municipality of NovaFriburgo, mountainous region on the state of Rio de Janeiro at an altitude of 1,065m. The experimental design was a randomized complete block design with four treatments: black oat, lupines albus, consortium and weeds, with four replications each, totaling 16 plots in the first stage of work, experiment 1. On the experiment 2, the plots were subdivided into two management systems, mechanical, where the plants were mowed and chemical, which occurred application of glyphosate herbicide, for the deposition of the straws on the ground. On the first part, productivity of green manure was evaluated, as well as the accumulation of nutrients and the epigaeous fauna associated to vegetation. The second part, after the management of the green manure, aimed the evaluation of mass loss of plant residues, epigaeous fauna and associated soil macrofauna. The main results showed that the lupine, single or consortium obtained satisfactory productivity, both in terms of biomass and the amount of accumulated nutrients, presenting potential for use in the mountainous region of Rio de Janeiro. The loss of mass of the residues was affected by the use of herbicide. The community of epigaeous fauna was not a good indicator because it didn?t suffer significant changes before or after the green manure management. The colembolas population was negatively afected by the herbicide. The soil macrofauna was more sensitive to the diferent forms of management, and the reduction of the density soil organisms could be observed up to 10 times when the plants were sprayed with herbicide. It was also noted the reduction on the macrofauna diversity. There was no difference in the chemical composition of the soil due to different covers and forms of management / Visando obter informa??es que ap?iem a proposi??o de manejos de gest?o da biodiversidade, que viabilizem sistemas de produ??o sustent?veis e garantam a qualidade dos recursos naturais, este estudo pretende colaborar com o aumento da produtividade agr?cola com base no uso da aduba??o verde, de forma sustent?vel. Nesse sentido, o presente trabalho teve como objetivo avaliar o comportamento dos adubos verdes de inverno tremo?o-branco, aveia-preta e do cons?rcio entre os dois, em ambiente de montanha, e a influ?ncia do herbicida na taxa de decomposi??o das palhadas dessas plantas e na diversidade e abund?ncia da fauna do solo. O experimento de campo foi conduzido na ?rea da Escola T?cnica Agr?cola Estadual Rei Alberto I, localizada na Microbacia do Barrac?o dos Mendes, Munic?pio de Nova Friburgo, Regi?o Serrana do Estado do Rio de Janeiro, a uma altitude de 1.065 m. O Delineamento experimental adotado foi o de blocos casualizados, com quatro tratamentos: aveia-preta, tremo?o-branco, cons?rcio e plantas espont?neas, com quatro repeti??es cada, totalizando 16 parcelas na primeira etapa do trabalho, etapa I. Na etapa II, as parcelas foram subdivididas em duas formas de manejo, mec?nico, onde as plantas foram ro?adas, e qu?mico, onde ocorreu aplica??o do herbicida glifosato, para a deposi??o das palhadas sobre o solo. Na etapa I, estudou-se a produtividade das plantas de cobertura, bem como o ac?mulo de nutrientes e a fauna ep?gea associada ?vegeta??o. Na segunda etapa, ap?s o manejo das plantas de cobertura, foi realizada a avalia??o da perda de massa dos res?duos vegetais, fauna ep?gea e macrofauna ed?fica associadas a esses res?duos. Como principais resultados, observou-se que o tremo?o, solteiro ou consorciado, obteve produtividade satisfat?ria, tanto em termos de fitomassa, quanto de quantidades de nutrientes acumulados, apresentando potencial para o uso na Regi?o Serrana do Rio de Janeiro. A perda de massa dos res?duos vegetais foi afetada com o uso de herbicida. A comunidade da fauna ep?gea n?o foi um bom indicador, pois n?o sofreu significativas modifica??es antes ou ap?s o manejo das plantas de cobertura. No entanto, as popula??es de col?mbolos foram afetadas negativamente pelo herbicida. J? a comunidade da macrofauna ed?fica se mostrou mais sens?vel ?s formas de manejo, sendo observada a redu??o da densidade dos organismos do solo ? metade e em at? 10 vezes, quando as plantas foram manejadas com herbicida. Observou-se tamb?m redu??o da diversidade da macrofauna. N?o houve diferen?a na composi??o qu?mica do solo em fun??o das diferentes coberturas e formas de manejo
42

Pratylenchus brachyurus x algodoeiro: patogenicidade, métodos de controle e caracterização molecular de populações / Pratylenchus brachyurus x cotton: pathogenicity, control methods and molecular characterization of populations

Machado, Andressa Cristina Zamboni 04 October 2006 (has links)
Pratylenchus brachyurus é um dos nematóides mais disseminados na cultura do algodão nas áreas produtoras do Brasil. Sua patogenicidade ao algodoeiro, entretanto, é pouco estudada. Os objetivos deste trabalho foram: i) correlacionar níveis populacionais iniciais crescentes de P. brachyurus (0, 12.000, 30.000 e 75.000 exemplares/ planta) com os danos causados ao algodoeiro \'Delta Opal\'; ii) avaliar a patogenicidade de populações de P. brachyurus em algodoeiros \'Delta Opal\' e \'Fibermax 966\'; iii) testar cultivares de algodão em relação à reprodução de três populações de P. brachyurus ; iv) caracterizar a relação parasito-hospedeiro (em termos de suscetibilidade/resistência) de alguns adubos verdes, coberturas vegetais e pastagens a Pratylenchus brachyurus; v) caracterizar molecularmente populações de P. brachyurus, através de PCR-RFLP e seqüenciamento da região ITS-1 do rDNA. Os resultados sugerem que P. brachyurus é patógeno pouco agressivo da cultura do algodão, já que não se verificaram danos significativos às plantas em densidades populacionais do nematóide inferiores a 12.000 exemplares/ planta. Em relação às cultivares, todas foram suscetíveis a P. brachyurus . Entre as espécies vegetais testadas, as que se mostraram resistentes a P. brachyurus foram Crotalaria spectabilis, C. breviflora, amaranto \'BRS Alegria\', nabo forrageiro \'Comum\' e as cultivares de aveia preta Campeira Mor, IPFA 99006, Comum, CPAO 0010 e Garoa. As análises de PCRRFLP revelaram variabilidade genética entre as diferentes populações de P. brachyurus estudadas, em função dos diferentes padrões de bandas encontrados para as populações estudadas. O seqüenciamento da região ITS-1 do rDNA confirmou a variabilidade observada pela digestão enzimática, além de evidenciar heterogeneidade das regiões 18S e ITS-1 do rDNA de P. brachyurus / Although Pratylenchus brachyurus is widespread in Brazilian cotton fields, information about its importance as a cotton pathogen is scarce. The objectives of this work were: i) correlate crescent initial population densities (0; 12,000; 30,000; and 75,000 nematodes/ plant) with damage on cotton \'Delta Opal\'; ii) measure the pathogenic effect of P. brachyurus on cotton \'Delta Opal\' and \'Fibermax 966\'; iii) characterize the reaction of cotton cultivars to three populations of P. brachyurus ; iv) characterize the host reaction (in terms of susceptibility/ resistance) of some green manures, cover crops and pastures to two populations of P. brachyurus; v) characterize different populations of P. brachyurus by PCR-RFLP and sequencing of ITS-1 rDNA region. Results suggest that P. brachyurus is an eventual pathogen of cotton, since high population levels were necessary to reduce plant growth (< 12,000 nematodes/ plant). All cotton cultivars tested were rated as susceptible to P. brachyurus In relation to crop species tested, Crotalaria spectabilis, C. breviflora, amaranth \'BRS Alegria\', oil radish \'Comum\', and the black oat cultivars Campeira Mor, IPFA 99006, Comum, CPAO 0010, and Garoa were resistant to P. brachyurus PCR-RFLP showed intraspecific variability for different population of P. brachyurus studied. Sequencing of the ITS-1 rDNA region confirmed the results of the enzymatic digestion and demonstrated heterogeneity of 18S and ITS-1 rDNA regions of P. brachyurus.
43

Uso contínuo de coberturas vegetais em citros: influência no banco de sementes, na comunidade infestante e nas características químicas do solo / Continuous usage of cover crops in citrus: influence in seedbank, weeds, and soil\'s chemical characteristics

San Martín Matheis, Hector Alonso 14 August 2008 (has links)
Nos últimos anos os consumidores, em especial do mercado externo, estão interessados e preocupados cada vez mais com a segurança alimentar, principalmente no que se refere à forma de produção. Esse panorama tem motivado a busca por alternativas de baixo impacto ambiental. Uma delas é o uso de coberturas vegetais ou adubação verde. Nesse contexto a presente pesquisa teve como objetivo avaliar a influência do uso contínuo de coberturas vegetais em pomar de citros sobre os padrões de infestação e banco de sementes das plantas daninhas, assim como as características químicas do solo. O experimento foi realizado em pomar de laranja \'Pêra\' (Citrus sinenesis (L.) Osbeck) na área experimental da Escola Superior de Agricultura \"Luiz de Queiroz\", Universidade de São Paulo (USP), Piracicaba, SP. O delineamento utilizado foi de blocos ao acaso em esquema fatorial 4 x 2 x 2. Os tratamentos consistiram da combinação de quatro coberturas vegetais, dois tipos de roçadeira e dois tipos de adubação. As coberturas vegetais utilizadas foram labe-labe (Dolichos lablab L.), guandu-anão (Cajanus cajan L. Millsp cv IAPAR 43), milheto (Pennisetum glaucum (L.) Leeke) e infestação natural do pomar de laranja. As roçadeiras utilizadas foram do tipo lateral e convencional e a adubação foi realizada na entrelinha e na projeção da copa da planta cítrica. Pelos dados obtidos pode-se observar que: as coberturas mortas produzidas pela infestação natural e pelo labe-labe contribuem significativamente na redução das populações de plantas daninhas afetando o banco de sementes; nas linhas das laranjeiras as plantas daninhas dicotiledôneas ocorreram com maior freqüência e com maior importância relativa em relação às monocotiledôneas; o deslocamento contínuo de cobertura morta da infestação natural promoveu alterações no pH, matéria orgânica (MO) e magnésio (Mg); o deslocamento contínuo de cobertura morta do labe-labe incrementou os teores de fósforo (P), cálcio (Ca), magnésio (Mg) e saturação por bases (V%). Sendo assim pode se concluir que o labe-labe pode constituir-se em alternativa promissora para uso como cobertura intercalar na cultura de citros. / In the last few years, the consumers, especially those of the external market, have become more and more interested in food security, namely on what it refers to the means of production. This fact has motivated the search for alternatives of low environmental impact, and one of these is the use cover crops or green manure. In this context the current research aimed the evaluation of the influence of continuous usage of plant cover in citrus orchards over the patterns of infestation and weed seed bank, as well as the soil\'s chemical characteristics. The experiment was carried out in a \"Pêra\" orange orchard (Citrus sinensis (L.) Osbeck) at the experimental area of Escola Superior de Agricultura \"Luiz de Queiroz\", University of São Paulo (USP), Piracicaba, SP. The experiment was conducted in random blocks in a 4 x 2 x 2 factorial scheme. The treatment consisted on the combination of four cover crop, two kinds of mowers and two kinds of manure. The cover crops used were lab-lab Dolichos lablab L., Cajanus cajan L. Millsp cv IAPAR 43, Pennisetum glaucum L. Leeke and natural infestation of the orange orchard. Lateral and conventional mowers were used, and the fertilization was made on inter row as well as on the projection of the trees\' crowns. The following facts were observed from the data that were gathered: the plant cover produced by natural infestation and D.lablab contributed significantly for the reduction of the weeds\' population, and thus having an effect on the seed bank; at the citrus tree\'s rows the dicotyledonous plants had higher relative frequence and relative importance than monocotiledonous plants; the continuous displacement of mulch natural infestation increased pH, organic matter (OM) and magnesium (Mg); the continuous displacement of mulch D.lablab increased phosphorus (P), calcium (Ca) and magnesium (Mg) levels and base saturation (V%). Thus, we can conclude that D.lablab can be a promising alternative as cover crop in citrus cultivation.
44

Uso contínuo de coberturas vegetais em citros: influência no banco de sementes, na comunidade infestante e nas características químicas do solo / Continuous usage of cover crops in citrus: influence in seedbank, weeds, and soil\'s chemical characteristics

Hector Alonso San Martín Matheis 14 August 2008 (has links)
Nos últimos anos os consumidores, em especial do mercado externo, estão interessados e preocupados cada vez mais com a segurança alimentar, principalmente no que se refere à forma de produção. Esse panorama tem motivado a busca por alternativas de baixo impacto ambiental. Uma delas é o uso de coberturas vegetais ou adubação verde. Nesse contexto a presente pesquisa teve como objetivo avaliar a influência do uso contínuo de coberturas vegetais em pomar de citros sobre os padrões de infestação e banco de sementes das plantas daninhas, assim como as características químicas do solo. O experimento foi realizado em pomar de laranja \'Pêra\' (Citrus sinenesis (L.) Osbeck) na área experimental da Escola Superior de Agricultura \"Luiz de Queiroz\", Universidade de São Paulo (USP), Piracicaba, SP. O delineamento utilizado foi de blocos ao acaso em esquema fatorial 4 x 2 x 2. Os tratamentos consistiram da combinação de quatro coberturas vegetais, dois tipos de roçadeira e dois tipos de adubação. As coberturas vegetais utilizadas foram labe-labe (Dolichos lablab L.), guandu-anão (Cajanus cajan L. Millsp cv IAPAR 43), milheto (Pennisetum glaucum (L.) Leeke) e infestação natural do pomar de laranja. As roçadeiras utilizadas foram do tipo lateral e convencional e a adubação foi realizada na entrelinha e na projeção da copa da planta cítrica. Pelos dados obtidos pode-se observar que: as coberturas mortas produzidas pela infestação natural e pelo labe-labe contribuem significativamente na redução das populações de plantas daninhas afetando o banco de sementes; nas linhas das laranjeiras as plantas daninhas dicotiledôneas ocorreram com maior freqüência e com maior importância relativa em relação às monocotiledôneas; o deslocamento contínuo de cobertura morta da infestação natural promoveu alterações no pH, matéria orgânica (MO) e magnésio (Mg); o deslocamento contínuo de cobertura morta do labe-labe incrementou os teores de fósforo (P), cálcio (Ca), magnésio (Mg) e saturação por bases (V%). Sendo assim pode se concluir que o labe-labe pode constituir-se em alternativa promissora para uso como cobertura intercalar na cultura de citros. / In the last few years, the consumers, especially those of the external market, have become more and more interested in food security, namely on what it refers to the means of production. This fact has motivated the search for alternatives of low environmental impact, and one of these is the use cover crops or green manure. In this context the current research aimed the evaluation of the influence of continuous usage of plant cover in citrus orchards over the patterns of infestation and weed seed bank, as well as the soil\'s chemical characteristics. The experiment was carried out in a \"Pêra\" orange orchard (Citrus sinensis (L.) Osbeck) at the experimental area of Escola Superior de Agricultura \"Luiz de Queiroz\", University of São Paulo (USP), Piracicaba, SP. The experiment was conducted in random blocks in a 4 x 2 x 2 factorial scheme. The treatment consisted on the combination of four cover crop, two kinds of mowers and two kinds of manure. The cover crops used were lab-lab Dolichos lablab L., Cajanus cajan L. Millsp cv IAPAR 43, Pennisetum glaucum L. Leeke and natural infestation of the orange orchard. Lateral and conventional mowers were used, and the fertilization was made on inter row as well as on the projection of the trees\' crowns. The following facts were observed from the data that were gathered: the plant cover produced by natural infestation and D.lablab contributed significantly for the reduction of the weeds\' population, and thus having an effect on the seed bank; at the citrus tree\'s rows the dicotyledonous plants had higher relative frequence and relative importance than monocotiledonous plants; the continuous displacement of mulch natural infestation increased pH, organic matter (OM) and magnesium (Mg); the continuous displacement of mulch D.lablab increased phosphorus (P), calcium (Ca) and magnesium (Mg) levels and base saturation (V%). Thus, we can conclude that D.lablab can be a promising alternative as cover crop in citrus cultivation.
45

Sistema Org?nico de Produ??o de Mandioca Consorciada com Milho e Caupi / Organic System of Cassava Production Intercropped with Corn and Cowpea

Devide, Antonio Carlos Pries 27 April 2006 (has links)
Made available in DSpace on 2016-04-28T14:58:30Z (GMT). No. of bitstreams: 1 2006-Antonio Carlos Pries Devide.pdf: 4000298 bytes, checksum: 757aca032c469431899c5eb8262fecf5 (MD5) Previous issue date: 2006-04-27 / Organic systems were evaluated for cassava root production directed to human comsuption in natura, at Serop?dica, Metropolitan Region of Rio de Janeiro State. Treatments consisted of: cassava ('IAC 576-70') single cropping and its intercropped with corn ('Eldorado'), cowpea ('Mau?') or corn plus cowpea. The organic management was standardized and the experimental area was submitted to artificial irrigation. Several phenological features were considered in the evaluations relating all three species under cultivation. Green (immature) corn ears were harvested at the point requiered for fresh marketing. The cowpea was included to function as green manure being cut at flowering and left on the soil surface. Both (corn and cowpea) species were sown between cassava rows, in an alternate design, following the first weeding of the main crop (cassava). The cultivar IAC 576-70 showed suitability with respect to organic management averaging approx. 31 Mg.ha-? of marketable roots. No significant differences were detected between cassava single cropping and any of the intercropping tested systems. Thus, the corn crop represented potential for additional income to the growers. Yield of Eldorado corn averaged 18.125 ears.ha-? correspponding to 5,1 Mg.ha-?. The harvested ears measured 19,5 cm of length by 4,5 cm of basal diameter (mean values) reaching the requirements for marketing, despite a certain frequency of grain failures at the apical end. Residues coming from cowpea cutting brought about an input close to 12 Mg.ha-1, which meant an expressive contribution in nutrient elements, specially nitrogen (about 44 kg N.ha-1). The legume crop, in addition, completely covered cassava inter-rows demonstrating its potential for controlling erosion and weeds. / Foram avaliados sistemas org?nicos de produ??o de mandioca para consumo humano in natura (aipim de mesa), em Serop?dica, Regi?o Metropolitana do Estado do Estado do Rio de Janeiro. Os tratamentos consistiram de: monocultivo da mandioca (cv. IAC 576-70) e de seus cons?rcios com o milho (cv. Eldorado), com o caupi (cv. Mau?) e com milho+caupi. O manejo org?nico foi padronizado e a ?rea experimental foi artificialmente irrigada. Foram considerados nas avalia??es diversos par?metros fenol?gicos referentes ?s tr?s esp?cies cultivadas. Do milho, foram colhidas espigas verdes (imaturas) no ponto apropriado para comercializa??o como tal. O caupi foi inclu?do como adubo verde, cortado na flora??o e deixado na superf?cie do solo. Ambos os consortes ocuparam as entrelinhas da mandioca, de modo alternado, sendo semeados ap?s a primeira capina da cultura principal. A cultivar IAC 576-70 mostrou-se adaptada ao manejo org?nico, com produtividade m?dia em ra?zes de padr?o comercial pr?xima a 31 Mg.ha-?. N?o houve diferen?as significativas entre o monocultivo e os tr?s tipos de cons?rcio testados. Desse modo, a inclus?o do milho representou potencial de renda adicional ao produtor. A produ??o comercial da cv. Eldorado (m?dia) situou-se em 18.125 espigas.ha-?, o que correspondeu a 5,1 Mg.ha-?. Embora apresentando, com certa freq??ncia, falhas de grana??o na extremidade apical, as espigas foram adequadas para o mercado, medindo, em m?dia, 19,5 cm de comprimento por 4,5 cm di?metro basal. Os res?duos provenientes da ro?ada do caupi representaram um aporte de biomassa da ordem de 12 Mg.ha-?, com uma expressiva contribui??o em macronutrientes, sobretudo o nitrog?nio (cerca de 44 kg de N.ha-1). A leguminosa, em adendo, dominou e cobriu as entrelinhas da mandioca, demonstrando seu potencial de controle ? eros?o e plantas espont?neas.
46

import?ncia da aduba??o verde na diversifica??o da produ??o agr?cola: uma abordagem participativa em assentamento rural na Baixada Fluminense / Importance of green manure in the diversification of agricultural production: a participative approach on rural settlement in Rio de Janeiro's Fluminense Lowland area.

Matheus, Andr?ia Cristina 04 May 2016 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-10-13T12:02:09Z No. of bitstreams: 1 2016 - Andr?ia Cristina Matheus.pdf: 2627280 bytes, checksum: 280f3799edc543851f302aefebda3f44 (MD5) / Made available in DSpace on 2017-10-13T12:02:09Z (GMT). No. of bitstreams: 1 2016 - Andr?ia Cristina Matheus.pdf: 2627280 bytes, checksum: 280f3799edc543851f302aefebda3f44 (MD5) Previous issue date: 2016-05-04 / The present work was performed with families of the Agrarian Reform Settlement Promised Land (Terra Prometida), located in the cities of Nova Igua?u and Duque de Caxias, in Fluminense Lowland (Baixada Fluminense), in the State of Rio de Janeiro. It aimed to evaluate strategies of management of productive systems, using green manure as a practice that contributes to the dynamics of agroecosystems, with its multiple functions. For this purpose, Demonstrative Units were set in the Integrated System of Agroecological Production (SIPA - ?Fazendinha Agroecol?gica km 47?) and in the Promised Land Settlement. A set of participatory methodological tools, based on the principles of research-action, was used, which oriented the development of the proposed actions and made it possible, in an integrated form, the practical evaluation of the sustainability of the practices, using indicators related to soil quality and crops health. The presented experience is inserted in the context of the strategy of performance of Coopaterra - Cooperative of Agroecological Producers Fertile Land, an aspect that allowed the collective conduction of the process together with the settlers, in a multiplying and participatory perspective. This was done recognizing the socio-economic importance of the areas of agrarian reform settlement and their families, as transforming agents of their own reality. The results are, mainly, in the appropriation of the practices by the settlers and the process of experimentation and exchange of knowledge carried out. However, it is required the continuity of the practices, on the basis of the actual conditions of the settlement and increasing their use for a larger set of settled families / O presente trabalho foi conduzido junto ?s fam?lias do Assentamento de Reforma Agr?ria Terra Prometida, localizado nos munic?pios de Nova Igua?u e Duque de Caxias, na Baixada Fluminense, no Estado do Rio de Janeiro. Objetivou-se avaliar estrat?gias de manejo dos sistemas produtivos, utilizando a aduba??o verde como pr?tica que contribui com a din?mica dos agroecossistemas, atrav?s das suas m?ltiplas fun??es. Para tanto, foram implantadas Unidades Demonstrativas no Sistema Integrado de Produ??o Agroecol?gica (SIPA - ?Fazendinha Agroecol?gica Km 47?) e no Assentamento Terra Prometida. Utilizou-se um conjunto de ferramentas metodol?gicas participativas com base no princ?pio da pesquisa-a??o que orientou o desenvolvimento das a??es propostas e possibilitou, de forma integrada, a avalia??o da sustentabilidade das pr?ticas, utilizando indicadores relacionados ? qualidade de solo e sanidade dos cultivos. A experi?ncia apresentada est? inserida no contexto da estrat?gia de atua??o da Coopaterra ? Cooperativa de Produtores Agroecol?gicos Terra F?rtil, aspecto que permitiu a condu??o do processo de forma coletiva junto aos assentados envolvidos, numa perspectiva multiplicadora e participativa. O trabalho foi realizado reconhecendo a import?ncia socioecon?mica das ?reas de assentamento de reforma agr?ria e das fam?lias, como agentes transformadores da pr?pria realidade. Os resultados est?o, principalmente, na sensibiliza??o dos assentados quanto ?s pr?ticas propostas e no processo de experimenta??o e troca de conhecimento. Contudo, compreende-se a necessidade da continuidade das pr?ticas, com base nas condi??es concretas do assentamento e a amplia??o para um conjunto maior de fam?lias assentadas
47

Determining optimum plant population densities for three annual green manure crops under weedy and weed-free conditions

Lawley, Yvonne 22 December 2004
Green manure crops are critical to maintaining soil fertility in organic cropping systems. However, little research has been conducted to address their contribution to weed control. Indianhead black lentil (Lens culinaris Medikus), AC Green Fix chickling vetch (Lathyrus sativus L.), and Trapper field pea (Pisum sativum L.) are legumes developed for use as annual green manure crops in the Northern Great Plains. Currently, no plant population density recommendations exist for these three species when grown as green manure crops under weedy conditions. The objective of this research was to determine the yield-density response of these three species under weedy and weedy-free conditions and to develop plant population density recommendations for use as annual green manure crops. Each species was grown at five plant population densities (10, 24, 64, 160, and 400 plants m-2) with weedy and weed-free treatments. Wild oat (Avena fatua L.) and wild mustard (Brassica kaber (D.C.) L.C. Wheeler) were planted in weedy treatments to supplement the natural weed community. Biomass samples and soil moisture measurements were taken at early bud and full bloom to simulate when these crops would be terminated. Biomass samples from the early bud stage were analysed for total nitrogen content. Green manure biomass production for all species was lower under weedy conditions. Weed biomass in weedy treatments decreased with increasing green manure plant population density for all species. Trapper field pea was the most competitive crop while Indianhead black lentil was the least competitive. Although total plot biomass differed among species and green manure crop density, changes in soil moisture levels were not greatly affected. No significant difference in total nitrogen concentration was found among green manure species. Differences in total nitrogen accumulation occurred because of differences in biomass production. Marginal cost analysis based on green manure seed costs and their nitrogen contribution to the value of subsequent wheat crop yield were used to determine optimum plant population densities. Under weedy conditions field pea and black lentil should be planted at densities of 49-78 and 223-300 plants m-2, respectively. Under weed-free conditions plant population densities for field pea and black lentil could be reduced to 45-60 and 184-223 plants m-2, respectively. No profitable plant population density was determined for chickling vetch when assuming a lower nitrogen contribution under both weedy and weed-free conditions. However, when assuming a higher nitrogen contribution, a profitable plant population density for chickling vetch of 24 plants m-2 was determined under weedy conditions and 32 plants m-2 under weed-free conditions.
48

Determining optimum plant population densities for three annual green manure crops under weedy and weed-free conditions

Lawley, Yvonne 22 December 2004 (has links)
Green manure crops are critical to maintaining soil fertility in organic cropping systems. However, little research has been conducted to address their contribution to weed control. Indianhead black lentil (Lens culinaris Medikus), AC Green Fix chickling vetch (Lathyrus sativus L.), and Trapper field pea (Pisum sativum L.) are legumes developed for use as annual green manure crops in the Northern Great Plains. Currently, no plant population density recommendations exist for these three species when grown as green manure crops under weedy conditions. The objective of this research was to determine the yield-density response of these three species under weedy and weedy-free conditions and to develop plant population density recommendations for use as annual green manure crops. Each species was grown at five plant population densities (10, 24, 64, 160, and 400 plants m-2) with weedy and weed-free treatments. Wild oat (Avena fatua L.) and wild mustard (Brassica kaber (D.C.) L.C. Wheeler) were planted in weedy treatments to supplement the natural weed community. Biomass samples and soil moisture measurements were taken at early bud and full bloom to simulate when these crops would be terminated. Biomass samples from the early bud stage were analysed for total nitrogen content. Green manure biomass production for all species was lower under weedy conditions. Weed biomass in weedy treatments decreased with increasing green manure plant population density for all species. Trapper field pea was the most competitive crop while Indianhead black lentil was the least competitive. Although total plot biomass differed among species and green manure crop density, changes in soil moisture levels were not greatly affected. No significant difference in total nitrogen concentration was found among green manure species. Differences in total nitrogen accumulation occurred because of differences in biomass production. Marginal cost analysis based on green manure seed costs and their nitrogen contribution to the value of subsequent wheat crop yield were used to determine optimum plant population densities. Under weedy conditions field pea and black lentil should be planted at densities of 49-78 and 223-300 plants m-2, respectively. Under weed-free conditions plant population densities for field pea and black lentil could be reduced to 45-60 and 184-223 plants m-2, respectively. No profitable plant population density was determined for chickling vetch when assuming a lower nitrogen contribution under both weedy and weed-free conditions. However, when assuming a higher nitrogen contribution, a profitable plant population density for chickling vetch of 24 plants m-2 was determined under weedy conditions and 32 plants m-2 under weed-free conditions.
49

Kai kurių medelyno ekologizavimo priemonių tyrimas / Research of some nurseries’ ecology tools

Grybas, Saulius 21 June 2010 (has links)
Magistro darbe tiriama kai kurių medelyno ekologizavimo priemonių įtaka paprastosios eglės (Picea abies (L.) H. Karst.) sodmenų augimui, vystimuisi, išlikimui, išeigai, dirvožemiui. Darbo objektas – vienerių metų paprastosios eglės sėjinukai ir 2+1 sodinukai bei sideralinis pūdymas. Darbo tikslas – ekologizuoti miško medelyną, pakeičiant mineralines trąšas organinėmis. Darbo metodai – literatūros loginė analizė, apskaitos aikštelių metodas; matematinės statistikos metodai. Darbo rezultatai. Paprastosios eglės sodmenų (pirmamečių sėjinukų ir 2+1 sodinukų) biometrinių požymių matavimai rodo, kad tręšimas kompostu, pagamintu iš mėšlo ir durpės, naudojant 50 ir 100 t ha-1 komposto normas yra netikslingas, nes sodmenims neužtikrinamas pakankamas mitybos lygis. Eglės sodmenis tikslinga tręšti 150 t ha-1 ir didesne komposto norma. Ši tręšimo norma sąlygoja panašius, kaip ir tręšiant mineralinėmis trąšomis, daugelio sodmenų antžeminės ir požeminės dalies biometrinius matavimus (augalų aukštį, šaknies kaklelio skersmenį, šoninių pumpurų skaičių, spyglių ilgį, pagrindinės šaknies ilgį, pirmos eilės šoninių šaknų skaičių). Dažniausiai biometriniai eglių sodmenų parametrai yra mažesni, nei mineralinėmis trąšomis tręštų sodmenų, tačiau skirtumai nėra esminiai. Eglės sodinukų, tręštų 150 t ha-1 komposto norma metinis aukščio prieaugis buvo 10 proc. patikimai mažesnis, nei tręštų mineralinėmis trąšomis sodinukų. Geriausiai eglės sėjinukai ir sodinukai augo dirvožemį patręšus 150 t ha-1... [toliau žr. visą tekstą] / The master thesis examined some of the nurseries’ ecology tools impact on simple spruce (Picea abies (L.) H. Karst.) planting stock cultivation, growth, survival, stocks yield, soil. Object of the work – first year seedlings and first year sapling of simple spruce and sideralic lea. The aim of work – to assess ecological organic fertilizer (green manure and compost) usage impact on simple spruce planting stock growth. Methods of the work – logical analysis of the literature, method of accounting sites, methods of mathematical statistics. The results of the work. Simple spruce planting stocks’ (first year seedlings and first year sapling) biometric features measurements demonstrate that fertilization with compost, made from dung and peat, with 50 and 100 t ha-1 compost rate is pointless, as sufficient nutritional level is not ensured for spruce planting stocks. Spruce planting stocks are appropriate to fertilize with 150 t ha-1 and a higher compost rate. This results in similar fertilization rate, as the fertilization with mineral fertilizers, the biometric measurements of many saplings in surface and underground part (plant height, root neck diameter, lateral bud number, spine length, main root length, the number of lateral root in first order). Frequently the biometric parameters of spruce planting stocks are lower than fertilized with mineral fertilizers, but the differences are not essential. The annual growth of spruce saplings, fertilized with 150 t ha-1 compost rate was... [to full text]
50

Implications of green manure amendments on soil seed bank dynamics

Short, Nicolyn January 2006 (has links)
[Truncated abstract] Weeds are a major limitation to agricultural and horticultural production and the main method of control is the use of herbicides. In addition to the resulting chemical pollution of the environment, the wide spread and continues use of herbicides have resulted in many weeds developing resistance to commonly used herbicides. This study investigated the potential of using green manures as a cultural method of control of weed invasion in agricultural fields. To understand the general mechanisms involved in the suppression of seed germination in green manure amended soils, seeds of crop species with little or no dormancy requirements were used in certain studies. Lettuce (Lactuca sativa) and cress (Lepidium sativum) seeds were sown to a sandy soil amended with green manures of lupin (Lupinus angustifolius), Brassica juncea, or oats (Avena sativa) to determine if the amendments affected seed germination and/or decay. It was hypothesised that the addition of plant material would increase the microbial activity of the soil thereby increasing seed decay, under laboratory and greenhouse conditions. Initial experiments used lettuce, cress and lupin seeds. Lettuce and cress are commonly used as standard test species for seed viability studies. Subsequent experiments used seeds of annual ryegrass (Lolium rigidum), silver grass (Vulpia bromoides), wild radish (Raphanus raphanistrum) and wild oat (Avena fatua) as these weed species are commonly found throughout agricultural regions in Western Australia. Amending the soil with lupin or Brassica green manure was established as treatments capable of developing environments suppressive to seed germination. Lupin residues as green manure showed the strongest inhibition of seed germination and seed decay. The decay of certain seeds was enhanced with changes to soil microbial activity, dissolved organic carbon and carbon and nitrogen amounts in lupin amended soil. Seeds of weed species were decayed in lupin amended soil, but showed varied degree of decay. Annual ryegrass and silver grass were severely decayed and wild oat and wild radish were less decayed, in lupin amended soil.

Page generated in 0.5827 seconds