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Comunidades de fungos micorrízicos arbusculares associadas à Pupunha e ao Cupuaçu cultivados em sistema agroflorestal e em monocultivo na Amazônia Central.; Comunnity of arbuscular mycorrhizal fungi associated with cupuaçu and peach palm in agroforestry and monoculture systems in the central Amazon region.

Silva Júnior, José Pereira da
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 31/03/2005 PT
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Os solos de terra firme da Amazônia são representados em sua maioria por Latossolos e Argissolos de alta acidez e baixa fertilidade, além de serem facilmente alterados fisicamente com a substituição da floresta primária por cultivos intensivos. O uso de estratégias biológicas, entre as quais se destacam as associaçãos micorrízicas arbusculares, no aperfeiçoamento de sistemas de manejo que racionalizem o uso dos recursos naturais da região, é fundamental para o desenvolvimento econômico contínuo, socialmente justo e ambientalmente sustentável. Para tanto, é necessário melhor entendimento de aspectos ecológicos da comunidade de fungos MA, com o fim de manejá-los. Dentro desse contexto, o objetivo dessa tese foi avaliar a simbiose micorrízica e as comunidades de fungos MA associados à pupunha (Bactris gasipaes Kunth) e ao cupuaçu (Theobroma grandiflorum Willd ex Spring Schum), quando cultivados em sistema agroflorestal (SAF) e em monocultivo, além de estimar a diversidade de comunidades de fungos MA associados às raízes de pupunha através de sequenciamento de mini biblieotecas de amplicons de região do gene ribossomal 18S. Foram realizadas coletas de solo e raízes em duas estações, seca e chuvosa. A colonização micorrízica arbuscular no cupuaçu e na pupunha foi alterada pelo sistema de manejo adotado...

Dynamics of aggregate stability influenced by soil management and crop residues

Taboada-Castro, Mercedes; Cristina Alves, Marlene; Whalen, Joann; Taboada, Teresa
Fonte: Taylor & Francis Inc Publicador: Taylor & Francis Inc
Tipo: Artigo de Revista Científica Formato: 2565-2575
ENG
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The type of tillage and crop systems used can either degrade or cause a recovery of the structure of agricultural soils. The objective of this study was to determine the structural stability of the soil using mean weight diameter (MWD) of soil aggregates in three different periods of a succession of crops consisting of beans/cover plants/maize under no tillage (NT) and conventional tillage (CT) management systems. Soils were sampled at 0- to 5-cm and 5- to 15-cm depths in three periods (P1, P2, P3): 1) November 2002 (spring/summer), 2) April 2003 (beginning of autumn), and 3) December 2003 (end of spring/beginning of summer). Aggregate stability was determined by wet sieving. The effects of the tillage systems, vegetal residues, and sampling depths on the structural stability of the aggregates were assessed and then related to organic matter (OM) contents. Aggregate stability showed temporal variation as a function of OM contents and sampling period. No tillage led to high MWD values in all study periods. The lowest MWD values and OM contents were observed 4 months after the management of the residues of cover plants. This finding is consistent with the fact that at the time of the samplings, most of the OM had already mineralized. The residues of sunn-hemp...

Adubação nitrogenada no feijoeiro em sucessão a milho e braquiária em plantio direto

Mingotte, Fabio Luiz Checchio
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Dissertação de Mestrado Formato: iii, 65 f.: il.
POR
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Pós-graduação em Agronomia (Produção Vegetal) - FCAV; O objetivo deste trabalho foi avaliar a influência da adubação nitrogenada no feijoeiro em sucessão à milho e braquiária em plantio direto. Os experimentos foram conduzidos em Jaboticabal (SP), num latossolo vermelho eutróférrico. Foi utilizada a cultivar de feijoeiro IPR Juriti em parcelas subdivididas, com três repetições, dispostas em blocos casualizados. As parcelas foram compostas por três sistemas de cultivos, representados por milho exclusivo, milho consorciado com Brachiaria ruziziensis e B. ruziziensis exclusiva (cultivos de verão) antecedendo a cultura do feijoeiro (cultivo de inverno-primavera com uso de irrigação), tendo como subparcelas cinco doses de nitrogênio (0, 40, 80, 120 e 160 kg ha-1) aplicadas em cobertura no estádio V4-4. O cultivo de braquiária favorece a formação de palhada no sistema de plantio direto não afetando a produtividade de grãos do milho em consórcio. O feijoeiro em sucessão a esse sistema apresenta produtividade de grãos em torno de 3.000 kg ha-1, não ocorrendo resposta à adubação nitrogenada em cobertura...

Long-term C-CO2 emissions and carbon crop residue mineralization in an oxisol under different tillage and crop rotation systems

Campos,Ben-Hur Costa de; Amado,Telmo Jorge Carneiro; Tornquist,Carlos Gustavo; Nicoloso,Rodrigo da Silveira; Fiorin,Jackson Ernani
Fonte: Sociedade Brasileira de Ciência do Solo Publicador: Sociedade Brasileira de Ciência do Solo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2011 EN
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Soil C-CO2 emissions are sensitive indicators of management system impacts on soil organic matter (SOM). The main soil C-CO2 sources at the soil-plant interface are the decomposition of crop residues, SOM turnover, and respiration of roots and soil biota. The objectives of this study were to evaluate the impacts of tillage and cropping systems on long-term soil C-CO2 emissions and their relationship with carbon (C) mineralization of crop residues. A long-term experiment was conducted in a Red Oxisol in Cruz Alta, RS, Brazil, with subtropical climate Cfa (Köppen classification), mean annual precipitation of 1,774 mm and mean annual temperature of 19.2 ºC. Treatments consisted of two tillage systems: (a) conventional tillage (CT) and (b) no tillage (NT) in combination with three cropping systems: (a) R0- monoculture system (soybean/wheat), (b) R1- winter crop rotation (soybean/wheat/soybean/black oat), and (c) R2- intensive crop rotation (soybean/ black oat/soybean/black oat + common vetch/maize/oilseed radish/wheat). The soil C-CO2 efflux was measured every 14 days for two years (48 measurements), by trapping the CO2 in an alkaline solution. The soil gravimetric moisture in the 0-0.05 m layer was determined concomitantly with the C-CO2 efflux measurements. The crop residue C mineralization was evaluated with the mesh-bag method...

Hydrological processes obtained on the plot scale under four simulated rainfall tests during the cycle of different crop systems

Bertol,Ildegardis; Ramos,Roger Robert; Barbosa,Fabrício Tondello; Ramos,Julio César; Bandeira,Douglas Henrique; Tanaka,Mitsui Shinosaka
Fonte: Sociedade Brasileira de Ciência do Solo Publicador: Sociedade Brasileira de Ciência do Solo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2014 EN
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The cropping system influences the interception of water by plants, water storage in depressions on the soil surface, water infiltration into the soil and runoff. The aim of this study was to quantify some hydrological processes under no tillage cropping systems at the edge of a slope, in 2009 and 2010, in a Humic Dystrudept soil, with the following treatments: corn, soybeans, and common beans alone; and intercropped corn and common bean. Treatments consisted of four simulated rainfall tests at different times, with a planned intensity of 64 mm h-1 and 90 min duration. The first test was applied 18 days after sowing, and the others at 39, 75 and 120 days after the first test. Different times of the simulated rainfall and stages of the crop cycle affected soil water content prior to the rain, and the time runoff began and its peak flow and, thus, the surface hydrological processes. The depth of the runoff and the depth of the water intercepted by the crop + soil infiltration + soil surface storage were affected by the crop systems and the rainfall applied at different times. The corn crop was the most effective treatment for controlling runoff, with a water loss ratio of 0.38, equivalent to 75 % of the water loss ratio exhibited by common bean (0.51)...

SOIL FUNGISTASIS AGAINST FUSARIUM GRAMINEARUM UNDER DIFFERENT CROP MANAGEMENT SYSTEMS

Lisboa,Bruno Brito; Bayer,Cimélio; Passaglia,Luciane Maria Pereira; Camargo,Flávio Anastácio de Oliveira; Beneduzi,Anelise; Ambrosini,Adriana; Vargas,Luciano Kayser
Fonte: Sociedade Brasileira de Ciência do Solo Publicador: Sociedade Brasileira de Ciência do Solo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2015 EN
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Soil management, in terms of tillage and cropping systems, strongly influences the biological properties of soil involved in the suppression of plant diseases. Fungistasis mediated by soil microbiota is an important component of disease-suppressive soils. We evaluated the influence of different management systems on fungistasis against Fusarium graminearum, the relationship of fungistasis to the bacterial profile of the soil, and the possible mechanisms involved in this process. Samples were taken from a long-term experiment set up in a Paleudult soil under conventional tillage or no-tillage management and three cropping systems: black oat (Avena strigose L.) + vetch (Vicia sativa L.)/maize (Zea mays L.) + cowpea (Vigna sinensis L.), black oat/maize, and vetch/maize. Soil fungistasis was evaluated in terms of reduction of radial growth of F. graminearum, and bacterial diversity was assessed using ribosomal intergenic spacer analysis (RISA). A total of 120 bacterial isolates were obtained and evaluated for antibiosis, and production of volatile compounds and siderophores. No-tillage soil samples showed the highest level of F. graminearum fungistasis by sharply reducing the development of this pathogen. Of the cropping systems tested...

Cultivable bacteria isolated from apple trees cultivated under different crop systems: Diversity and antagonistic activity against Colletotrichum gloeosporioides

Passos,João Frederico M. dos; Costa,Pedro B. da; Costa,Murilo D.; Zaffari,Gilmar R.; Nava,Gilberto; Boneti,José Itamar; Oliveira,Andréia Mara R. de; Passaglia,Luciane M.P.
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2014 EN
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This study evaluated the diversity of cultivable plant growth-promoting (PGP) bacteria associated with apple trees cultivated under different crop management systems and their antagonistic ability against Colletotrichum gloeosporioides. Samples of roots and rhizospheric soil from apple trees cultivated in organic and conventional orchards in southern Brazil were collected, together with soil samples from an area never used for agriculture (native field). Bacteria were identified at the genus level by PCR-RFLP and partial sequencing of the 16S rRNA, and were evaluated for some PGP abilities. The most abundant bacterial genera identified were Enterobacter (27.7%), Pseudomonas (18.7%), Burkholderia (13.7%), and Rahnella (12.3%). Sixty-nine isolates presented some antagonist activity against C. gloeosporioides. In a greenhouse experiment, five days after exposure to C. gloeosporioides, an average of 30% of the leaf area of plants inoculated with isolate 89 (identified as Burkholderia sp.) were infected, whereas 60 to 73% of the leaf area of untreated plants was affected by fungal attack. Our results allowed us to infer how anthropogenic activity is affecting the bacterial communities in soil associated with apple tree crop systems, and to obtain an isolate that was able to delay the emergence of an important disease for this culture.

The influence of land use systems on soil and surface litter fauna in the western region of Santa Catarina

Bartz,Marie Luise Carolina; Brown,George Gardner; Orso,Renato; Mafra,Álvaro Luiz; Baretta,Dilmar
Fonte: Universidade Federal do Ceará Publicador: Universidade Federal do Ceará
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2014 EN
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The aim of this study was to evaluate the abundance of soil and surface litter fauna in the western region of Santa Catarina state, southern Brazil, in the following land use systems (LUS): no-tillage crops (NT), integrated crop-livestock (ICL), pasture (PA), Eucalyptus plantation (EP) and native forest fragments (NF). Sampling was done in three counties in the western region of Santa Catarina: Xanxerê, Chapecó and São Miguel do Oeste, in two seasons (winter and summer). The evaluation of soil/litter fauna in each LUS was performed by installing nine "pitfall traps" per sampling grid (3 x 3). The counties are true replicas. The soil for the chemical attributes was collected at the same sampling points for soil fauna. Altogether, 17 taxa were identified in the five LUS. The presence of groups of fauna was influenced by the type of soil management used. The LUS NF and EP provide better soil conditions for the development of a higher diversity of soil fauna groups compared to other LUS, which showed varying degrees of human intervention, regardless of the sampling season (winter or summer). However, annual crop systems NT and ICL groups showed greater richness and total abundance when compared to the perennial systems (EP and PA). Principal component analysis is an important tool in the study of biological indicators of sustainability because it allows use of soil attributes (chemical and physical) as explanatory environmental variables...

Cultivable bacteria isolated from apple trees cultivated under different crop systems: Diversity and antagonistic activity against Colletotrichum gloeosporioides

dos Passos, João Frederico M.; da Costa, Pedro B.; Costa, Murilo D.; Zaffari, Gilmar R.; Nava, Gilberto; Boneti, José Itamar; de Oliveira, Andréia Mara R.; Passaglia, Luciane M.P.
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica
Publicado em /09/2014 EN
Relevância na Pesquisa
46.04%
This study evaluated the diversity of cultivable plant growth-promoting (PGP) bacteria associated with apple trees cultivated under different crop management systems and their antagonistic ability against Colletotrichum gloeosporioides. Samples of roots and rhizospheric soil from apple trees cultivated in organic and conventional orchards in southern Brazil were collected, together with soil samples from an area never used for agriculture (native field). Bacteria were identified at the genus level by PCR-RFLP and partial sequencing of the 16S rRNA, and were evaluated for some PGP abilities. The most abundant bacterial genera identified were Enterobacter (27.7%), Pseudomonas (18.7%), Burkholderia (13.7%), and Rahnella (12.3%). Sixty-nine isolates presented some antagonist activity against C. gloeosporioides. In a greenhouse experiment, five days after exposure to C. gloeosporioides, an average of 30% of the leaf area of plants inoculated with isolate 89 (identified as Burkholderia sp.) were infected, whereas 60 to 73% of the leaf area of untreated plants was affected by fungal attack. Our results allowed us to infer how anthropogenic activity is affecting the bacterial communities in soil associated with apple tree crop systems, and to obtain an isolate that was able to delay the emergence of an important disease for this culture.

Risk in agriculture : a study of crop yield distributions and crop insurance; Study of crop yield distributions and crop insurance

Gayam, Narsi Reddy
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 60 leaves; 2690788 bytes; 2692406 bytes; application/pdf; application/pdf
ENG
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Agriculture is a business fraught with risk. Crop production depends on climatic, geographical, biological, political, and economic factors, which introduce risks that are quantifiable given the appropriate mathematical and statistical methodologies. Accurate information about the nature of historical crop yields is an important modeling input that helps farmers, agribusinesses, and governmental bodies in managing risk and establishing the proper policies for such things as crop insurance. Explicitly or implicitly, nearly all farm decisions relate in some way to the expectation of crop yield. Historically, crop yields are assumed to be normally distributed for a statistical population and for a sample within a crop year. This thesis examines the assumption of normality of crop yields using data collected from India involving sugarcane and soybeans. The null hypothesis (crop yields are normally distributed) was tested using the Lilliefors method combined with intensive qualitative analysis of the data. Results show that in all cases considered in this thesis, crop yields are not normally distributed.; (cont.) This result has important implications for managing risk involving sugarcane and soybeans grown in India. The last section of this thesis examines the impact of crop yield non normality on various insurance programs...

Soil chemical attributes for different land-use systems in semi arid region.

TONUCCI, R. G.; PRIMO, A. A.; MELO, M. D.; VIEIRA, L. V.; FERNANDES, J. K. S.; SOUZA, H. A. de
Fonte: In: WORLD CONGRESS ON INTEGRATED CROP-LIVESTOCK-FOREST SYSTEMS; INTERNATIONAL SYMPOSIUM ON INTEGRATED CROP-LIVESTOCK SYSTEMS, 3., 2015, Brasília, DF. Towards sustainable intensification: proceedings. Brasília, DF: Embrapa, 2015. Publicador: In: WORLD CONGRESS ON INTEGRATED CROP-LIVESTOCK-FOREST SYSTEMS; INTERNATIONAL SYMPOSIUM ON INTEGRATED CROP-LIVESTOCK SYSTEMS, 3., 2015, Brasília, DF. Towards sustainable intensification: proceedings. Brasília, DF: Embrapa, 2015.
Tipo: Resumo em anais de congresso (ALICE)
EN
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Introduction the evaluation of soil fertility in already placed agroforestry systems allows inferences of greater managements practices and nutrient cycling. In the semi arid region the use of integrated systems provides optimization of land and the efficient use of resources, thus becomes preponderant know soil chemical properties to assist in soil management. It aimed to evaluate soil chemical properties of agroforestry systems already placed.; 2015

Trees and grass contribution to soil organic carbon in agroforestry systems.

TONUCCI, R. G.; GARCIA, R.; NAIR, V.
Fonte: In: WORLD CONGRESS ON INTEGRATED CROP-LIVESTOCK-FOREST SYSTEMS; INTERNATIONAL SYMPOSIUM ON INTEGRATED CROP-LIVESTOCK SYSTEMS, 3., 2015, Brasília, DF. Towards sustainable intensification: proceedings. Brasília, DF: Embrapa, 2015. Publicador: In: WORLD CONGRESS ON INTEGRATED CROP-LIVESTOCK-FOREST SYSTEMS; INTERNATIONAL SYMPOSIUM ON INTEGRATED CROP-LIVESTOCK SYSTEMS, 3., 2015, Brasília, DF. Towards sustainable intensification: proceedings. Brasília, DF: Embrapa, 2015.
Tipo: Resumo em anais de congresso (ALICE)
EN
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Agroforestry systems have the potential to enhance carbon (C) sequestration in soil compared with treeless (agricultural) systems (Montagnini & Nair, 2004). When one type of vegetation is replaced with another, stable isotope contents (?13 C) values can be used to identify soil organic carbon (SOC) derived from residues in the native vegetation and the new vegetation based on discrimination between C3 and C4 plants. The present study aimed to assessing the impact of difference land-use systems on C3 and C4 contribution to SOC. The experimental area is located inside the Cerrado biome. Soil samples were taken from six different land-use sites: (i) native local forest; (ii) Eucalyptus forest (EF) established in 1985 (OEC); (iii) EF established in 2004 (NEC); (iv) pasture of B. decumbens; (v) Agroforestry System (AF) established on 1994 (OAF); and (vi) AF established on 2004 (NAF). The establishment on AF was placed first with the eucalyptus planted and rice (Oryza sativa), soybean (Glycine max) and braquiaria grass (B. Brizantha cv. Marandu) in between trees rows. Soil was collected from four depths (0-10; 10-20; 20-50 and 50-100 cm). For stable C isotope analysis, whole soil was analyzed mass spectrometer. The percentage of SOC derived from the Brachiaria ssp....

Crop Production and Road Connectivity in Sub-Saharan Africa : A Spatial Analysis

Dorosh, Paul; Wang, Hyoung-Gun; You, Liang; Schmidt, Emily
Fonte: Banco Mundial Publicador: Banco Mundial
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This study examines the relationship between transport infrastructure and agriculture in Sub-Saharan Africa using new data obtained from geographic information systems (GIS). First, the authors analyze the impact of road connectivity on crop production and choice of technology. Second, they explore the impact of investments that reduce road travel times. Finally, they show how this type of analysis can be used to compare cost-benefit ratios for alternative road investments in terms of agricultural output per dollar invested. The authors find that agricultural production is highly correlated with proximity (as measured by travel time) to urban markets. Likewise, adoption of high-productive/high-input technology is negatively correlated with travel time to urban centers. There is therefore substantial scope for increasing agricultural production in Sub-Saharan Africa, particularly in more remote areas. Total crop production relative to potential production is 45 percent for areas within four hours travel time from a city of 100...

Potential Impact of Climate Change on Resilience and Livelihoods in Mixed Crop-Livestock Systems in East Africa

Herrero, Mario; Jones, Peter G; Karanja, Stanley; Mutie, Ianetta; Rufino, Mariana C; Thornton, Philip K
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
EN_US
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Climate-induced livelihood transitions in the agricultural systems of Africa are increasingly likely. A recent study by Jones and Thornton (2009) points to the possibility of such climate-induced livelihood transitions in the mixed crop-livestock rainfed arid-semiarid systems of Africa. These mixed systems cover over one million square kilometers of farmland in West Africa, Eastern Africa, and Southeastern Africa. Their characteristically scant rainfall usually causes crop failure in one out of every six growing seasons and is thus already marginal for crop production. Under many projected climate futures, these systems will become drier and even more marginal for crop production. This will greatly increase the risk of cropping and among the several possible coping and adaptation mechanisms, (e.g. totally abandoning farming, diversification of income-generating activities such as migration and off-farm employment, etc.) agro-pastoralists may alter the relative emphasis that they currently place on the crop and livestock components of the farming system in favor of livestock. There has been only limited analysis on what such climate induced transitions might look like...

SELECTION OF HERBICIDES TARGETING THE USE IN CROP SYSTEMS CULTIVATED WITH SHOWY CROTALARIA

BRAZ,G. B. P; OLIVEIRA JR,R. S; CONSTANTIN,J.; TAKANO,H. K.; CHASE,C. A.; FORNAZZA,F. G. F.; RAIMONDI,R. T.
Fonte: Sociedade Brasileira da Ciência das Plantas Daninhas Publicador: Sociedade Brasileira da Ciência das Plantas Daninhas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2015 EN
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ABSTRACT The increase in the area planted with Crotalaria spectabilishas occurred by several factors, highlighting the potential to reduce the nematodes, nitrogen fixation and the high production of biomass. By becoming a species sown as a crop, it is necessary to control the weeds that coexist with showy crotalaria. This change in the use of this crop creates the possibility of this specie becoming a weed. The aim of this study was to assess the potential use of herbicides applied in preemergence and postemergence of C.spectabilisfor different purposes (control of volunteer and selectivity plants). Three experiments were installed in a greenhouse (two with herbicides applied in preemergence - in soils with distinct textural categories; and one experiment with herbicides applied in postemergence). The results of the experiments with herbicides applied in preemergence showed that: amicarbazone, atrazine, diuron, metribuzin, prometryn, fomesafen and sulfentrazone showed effectiveness for control of C.spectabilis in clayey soil. Besides these, flumioxazin and isoxaflutole also showed potential to be used in the control of showy crotalaria in soils with loam texture. In relation to the postemergence herbicides, atrazine, diuron, prometryn...

Soil water and nitrogen dynamics of farming systems on the upper Eyre Peninsula, South Australia

Adcock, Damien Paul
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado Formato: 1590322 bytes; 100539 bytes; application/pdf; application/pdf
Publicado em //2005 EN
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In the semi - arid Mediterranean - type environments of southern Australia, soil and water resources largely determine crop productivity and ultimately the sustainability of farming systems within the region. The development of sustainable farming systems is a constantly evolving process, of which cropping sequences ( rotations ) are an essential component. This thesis focused on two important soil resources, soil water and nitrogen, and studied the effects of different crop sequences on the dynamic of these resources within current farming systems practiced on the upper Eyre Peninsula of South Australia. The hypothesis tested was that : continuous cropping may alter N dynamics but will not necessarily alter water use efficiency in semi - arid Mediterranean - type environments. Continuous cropping altered N - dynamics ; increases in inorganic N were dependent on the inclusion of a legume in the cropping sequence. Associated with the increase in inorganic N supply was a decrease in WUE by the subsequent wheat crop. Overall, estimates of water use efficiency, a common index of the sustainability of farming systems, in this study concur with reported values for the semi - arid Murray - Mallee region of southern Australia and other semi - arid environments worldwide. Soil water balance and determination of WUE for a series of crop sequences in this thesis suggests that the adoption of continuous cropping may increase WUE and confer a yield benefit compared to crop sequences including a legume component in this environment. No differences in total water use ( ET ) at anthesis or maturity were measured for wheat regardless of the previous crop. Soil evaporation ( E [subscript s] ) was significantly affected by crop canopy development...

Reducing the Vulnerability of Moldova's Agricultural Systems to Climate Change : Impact Assessment and Adaptation Options

Sutton, William R.; Srivastava, Jitendra P.; Neumann, James E.; Iglesias, Ana; Boehlert, Brent B.
Fonte: Washington, DC: World Bank Publicador: Washington, DC: World Bank
Tipo: Publications & Research :: Publication; Publications & Research
EN_US
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Changes in climate and their impact on agricultural systems and rural economies are already evident throughout Europe and Central Asia (ECA). Adaptation measures now in use in Moldova, largely piecemeal efforts, will be insufficient to prevent impacts on agricultural production over the coming decades. There is growing interest at country and development partner levels to have a better understanding of the exposure, sensitivities, and impacts of climate change at farm level, and to develop and prioritize adaptation measures to mitigate the adverse consequences. The approach of this volume is predicated on strong country ownership and participation, and is defined by its emphasis on 'win-win' or 'no regrets' solutions to the multiple challenges posed by climate change for the farmers of Eastern Europe and Central Asia. The solutions are measures that increase resilience to future climate change, boost current productivity despite the greater climate variability already occurring, and limit greenhouse gas emissions-also known as 'climate-smart agriculture.' Specifically, this report provides a menu of climate change adaptation options for the agriculture and water resources sectors, along with specific recommendations that are tailored to three distinct Agro-Ecological Zones (AEZs) within Moldova. This menu reflects the results of three inter-related activities...

Cultivares de batata para sistemas orgânicos de produção; Potato cultivars for organic production systems

ROSSI, Fabrício; MELO, Paulo César T; AZEVEDO FILHO, Joaquim A; AMBROSANO, Edmilson J; GUIRADO, Nivaldo; SCHAMMASS, Eliana A; CAMARGO, Laís F
Fonte: Associação Brasileira de Horticultura Publicador: Associação Brasileira de Horticultura
Tipo: Artigo de Revista Científica
POR
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Informações a respeito de cultivares adaptadas ao sistema de cultivo orgânico são escassas. O objetivo deste estudo foi avaliar, sob sistema de cultivo orgânico, genótipos nacionais e estrangeiros desenvolvidos para o cultivo convencional, quanto ao potencial produtivo, em condições de campo. O experimento foi conduzido em 2008, no Pólo APTA Leste Paulista, em Monte Alegre do Sul-SP. O delineamento experimental foi em blocos ao acaso, com 18 tratamentos e quatro repetições. Cada parcela foi constituída por 80 batatas-semente, dispostas em quatro linhas de 5 m de comprimento, espaçadas de 80 cm, com 25 cm entre tubérculos. Os genótipos avaliados foram Agata, Asterix, Caesar, Cupido, Éden, Melody, Novella e Vivaldi, de origem estrangeira; e Apuã, Aracy, Catucha, IAC Aracy Ruiva, Itararé, Monte Alegre 172, IAC 6090, APTA 16.5, APTA 15.20 e APTA 21.54, nacionais. Foram avaliadas as características de produtividade total e comercial de tubérculos, massa média total e comercial de tubérculos, teor de matéria seca e severidade da pinta-preta (Alternaria solani). Os clones APTA 16.5, APTA 21.54 e IAC 6090, e as cultivares Cupido, Apuã, Itararé e Monte Alegre 172 foram os mais produtivos. 'APTA 21.54' superou os demais em relação a produtividade comercial (18...

Understanding sugarcane yield gap and bettering crop management through crop production efficiency.

MARIN, F. R.
Fonte: MARIN, F. R. (Ed.). Crop management - cases and tools for higher yield and sustainability. Croatia: InTech, 2012. Cap. 6. Publicador: MARIN, F. R. (Ed.). Crop management - cases and tools for higher yield and sustainability. Croatia: InTech, 2012. Cap. 6.
Tipo: Capítulo em livro técnico-científico (ALICE) Formato: p. 109-118.
EN
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The comparison among farming systems and regions would improve the understanding of how and what driving factors explains the crop yield variability over time and space. Very often, however, farm managers and policy makers fall in difficult to establish reliable indexes to compare farming systems plots and regions. Having a quantitate index, we could derive relationships regarding climate, soil and socioeconomic, as well as to determine which factors contribute or hinder the development in a given region and time. Monteith (1977) suggested agroecosystems as machines that utilize solar energy to maintain composition and organization. From a thermodynamic standpoint, the efficiency of any process can be expressed as the ratio of energy output to energy input. Since the 1970s, this concept has been applied to analyze the energy flow in agroecosystems, as well as to analyze the relation between biomass chemical energy and incident solar radiation. We could apply this approach to understand the regional agricultural development and crop yield gap, once it could elucidate biophysical factors, such as the pedoclimatic conditions, affecting crop yields at a local scale. However, for a broader evaluation, one should also include structural components...

Comunidades bacterianas en suelos bajo siembra directa en la región agropecuaria pampeana. Influencia del manejo y propuesta de nuevos indicadores biológicos; Bacterial communities in soils under no-till crop production in the pampas region. Influence of management and proposal of new biological indicators

Guerrero, Leandro Demián
Fonte: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires Publicador: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires
Tipo: info:eu-repo/semantics/doctoralThesis; tesis doctoral; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2012 SPA
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Los suelos son considerados uno de los ambientes más diversos y heterogéneos que se conocen. En ellos se producen innumerables procesos que permiten el reciclado y transformación de sustancias esenciales para la vida de plantas y animales. La mayoría de estos procesos son realizados por bacterias, y se ven afectados por distintos factores en el ambiente. Una de las principales causas que modifican estos ecosistemas es la producción agrícola. En los últimos tiempos el desarrollo de nuevas tecnologías, como la siembra directa podrían atenuar parcialmente el impacto de esta explotación. Sin embargo, el uso sustentable implica también la aplicación de prácticas de manejo, que incluyen rotaciones de cultivos, reposición de nutrientes y manejo integral de plagas. En este trabajo estudiamos la composición y dinámica de las comunidades de bacterias bajo prácticas contrastantes en siembra directa, con los objetivos de determinar de qué manera las prácticas agrícolas impactan sobre el suelo, y encontrar variaciones en las comunidades que puedan servir como indicadores de biológicos de calidad del suelo. Para el estudio se analizaron ambientes naturales y dos tratamientos de siembra directa que difieren principalmente en el régimen de rotación de cultivos...