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| Registros recuperados: 155 | |
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| Candido,Willame dos Santos; Soares,Renato Silva; Franco,Carolina Andrade; Diniz,Guilherme Matos Martins; Silva,Edgard Henrique Costa; Marin,Marcus Vinicius; Braz,Leila Trevisan. |
| Abstract: The objective of this work was to estimate the stability and genotypic adaptability of advanced lines and cultivars of curled green-leaf lettuce (Lactuca sativa), in different growing environments and seasons, using the REML/Blup mixed model. Ten genotypes, seven cropping environments, and two growing seasons were studied in 2015. Plant yield traits were evaluated, and data were subjected to the Selegen-REML/Blup software. Genotype stability and adaptability were analyzed using the harmonic mean of genotypic values (HMGV) and the relative performance of genotypic values (RPGV), respectively. The harmonic mean of RPGV (HMRPGV) was used to simultaneously estimate the stability, adaptability, and yield of breeding lines or cultivars. Considering the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lactuca sativa; Cropping systems; HMRPGV; Mixed models. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2018000300298 |
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| LIMA FILHO,JOSÉ MOACIR PINHEIRO. |
| The effect of intercropping on plant water status, gas exchange and productivity of maize (Zea mays L.) cv. Centralmex, and cowpea (Vigna unguiculata L. (Walp)) cv. Pitiuba were evaluated under semi-arid conditions at the Embrapa-Centro de Pesquisa Agropecuária do Trópico Semi-Árido (CPATSA) at Petrolina, PE, Brazil. The treatments were: maize and cowpea as sole crops, at a population of 40,000 plants ha-1, and intercropped at a population of 20,000 plants ha-1. The results obtained in this paper appear to be related to the degree of competition experienced by the components, mainly for water and light. Maize intercropped had higher values of leaf water potential, stomatal conductance, transpiration and photosynthesis than as sole crop. Intercropped cowpea... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Plant soil relations; Plant water relations; Gas exchange; Cropping systems. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2000000500008 |
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| Carvalho,Márcia Thaís de Melo; Madari,Beáta Emoke; Bastiaans,Lammert; Oort,Pepijn Adrianus Johannes van; Leal,Wesley Gabriel de Oliveira; Souza,Diego Mendes de; Santos,Roberto Carlos dos; Matsushige,Iva; Maia,Aline de Holanda Nunes; Heinemann,Alexandre Bryan; Meinke,Holger. |
| Abstract The objective of this work was to investigate the impact of the application of wood biochar, combined with N fertilizations, on N2O-N fluxes, nitrogen availability, and water-filled pore space (WFPS) of a clayey Oxisol under rice (wet season) and common bean (dry season) succession. Manual static chambers were used to quantify N2O-N fluxes from soil immediately after a single application of wood biochar (32 Mg ha-1) and after four crop seasons with N applications (90 kg ha-1 N). Soil ammonium (N-NH4+) and nitrate (N-NO3-) availability, as well as WFPS, was measured together with N2O-N fluxes. There was no interaction between biochar and N fertilization regarding N2O-N fluxes in any of the four seasons monitored, although these fluxes were clearly... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cropping systems; Gas fluxes; Greenhouse gases; Nitrate and ammonium; Soil amendment; Soil porosity. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2016000901203 |
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| Concenço,G; Salton,J.C; Secretti,M.L; Mendes,P.B; Brevilieri,R.C; Galon,L. |
| This study aims to assess the composition of weed communities as a function of distinct selection factors, at neighboring areas submitted to distinct soil management and diverse use for sixteen years. Four areas submitted to distinct managements (conventional tillage system; no-till system; integration crop/livestock and continuous livestock) were sampled in relation to the occurrence and severity of weed species by the beginning of the planting season, being estimated the relative abundance, relative frequency and relative dominance of each weed species under each area, as well as the Importance Value Index for each species. Areas were also compared by the Sørensen's similarity coefficient. Areas where pasture and grazing were never present, exhibited a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Integration crop/livestock; Cropping systems; Phytosociology. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582011000300005 |
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| MEHMOOD-UL-HASSAN,; QAYYUM,A.; SHER,A.; TAHIR,M.I.; AZEEM,M.; FAREED,A.. |
| ABSTRACT: Tillage practice has a significant role on weeds eradication and soil water conservation in crop production. Under semiarid agriculture, the monsoon rains (65%) are major source of water in Potohar, Pakistan, which can effectively be used mostly for winter crops production. To evaluate the impact of different tillage system for prevailing cropping systems and their weeds biomass under semiarid conditions, field experiment was conducted at the Arid University Research Farm Koont Rawalpindi (Pakistan) during crop growth seasons 2013-14 and 2014-15. Tillage systems as treatments were (a) three cultivations with a cultivator, as control treatment, (b) mold-board with two cultivations, (c) chisel-plough with two cultivations and (d) minimum tillage... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Tillage; Cropping systems; Weeds; Biomass; Semiarid. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582020000100231 |
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| Concenço,G; Salton,J.C; Brevilieri,R.C; Mendes,P.B; Secretti,M.L. |
| This study aimed at assessing the level of weed infestation indifferent areas that were submitted to different soil management for 16 years. Four management systems were studied: (1) agriculture only under conventional tillage system; (2) agriculture only under no-till system; (3) crop-livestock integrationcrop-livestock integration; (4) livestock only. These areas were sampled at three soil depths (0-5, 5-10 and 10-15 cm), and soil was stored in plastic pots and taken to a greenhouse, where soil moisture and weight were standardized. Soil was kept near 70% moisture field capacity, being revolved every 20 days when all seedling emerged from soil were counted, identified and collected for dry mass assessment. The soil coverage by weeds, number of weed... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Weeds; Cropping systems; Crop-livestock integration. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582011000400002 |
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| Hignight, Jeffrey A.; Watkins, K. Bradley; Anders, Merle M.. |
| No-till (NT) has been shown to reduce fuel, labor, and machinery costs compared to conventional-till (CT) but very few rice producers in Arkansas practice NT. The low adoption rate is most likely due to difficulties in management but also limited information on the profitability and risk of NT. Most rice producers are knowledgeable on NT costs savings but consider it less profitable due to yield reductions offsetting costs savings. This study evaluates production costs, crop yields, and economic risk of both NT and CT in five rice-based cropping systems (continuous rice, rice-soybean, rice-corn, rice-wheat, and rice-wheat-soybean-wheat). Yields, crop prices, and key input prices are simulated to create net return distributions. Stochastic efficiency... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Cropping systems; Rice; No-till; Certainty equivalent; Risk premium; Crop Production/Industries; Farm Management; Financial Economics; Land Economics/Use; Production Economics; Risk and Uncertainty. |
| Ano: 2010 |
URL: http://purl.umn.edu/56354 |
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| Singh, Sukhwinder; Park, Julian R.; Litten-Brown, Jennie. |
| Food for all continues to be a key issue, especially in the developing world where every fifth person is chronically undernourished. India, a fast growing developing country has also experienced serious food shortages for example in the mid 1960s. Punjab, a small northern Indian state has developed, particularly since the Green Revolution in the mid 1960s, to be a key agricultural area producing 13% of the food grains of India. Increased productivity brought economic benefits to farmers and led to the establishment of Wheat-Rice Cropping Pattern (WRCP) as the main agricultural system of Punjab which more recently has become reliant on underground water resources, agricultural machinery, chemical fertilisers and pesticides. More recently stagnating yields... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Agriculture; Cropping systems; Punjab; Sustainability; Environmental Economics and Policy; Farm Management. |
| Ano: 2011 |
URL: http://purl.umn.edu/116007 |
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| Chan, Stephanie; Caldwell, Brian; Rickard, Bradley J.. |
| This paper provides an economic analysis that compares the profitability and land management capability of four different organic cropping systems used to produce winter squash (Cucurbita pepo cv. ‘Delicata’) and cabbage (Brassica oleracea var. capitata cv.’ Farao’). The organic cropping systems are part of a long term experiment designed for vegetable production in the Northeast, and designed to maintain ecological integrity and contribute to environmental stewardship. Our research addresses the causal chain from soil processes to economic outcomes including soil quality, efficiency in cycling of nutrients, off-farm impacts, pressures from weeds, insects and diseases, crop yield and quality, and marketing opportunities. Interactive crop budgets were... |
| Tipo: Working Paper |
Palavras-chave: Cropping systems; Economic analysis; Organic production; Sustainable agriculture; Vegetables.; Farm Management. |
| Ano: 2010 |
URL: http://purl.umn.edu/121652 |
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| Hussain, Intizar; Marikar, Fuard; Jehangir, Waqar Ahmed. |
| A study of the enormous differences in agricultural productivity that exist across farms and regions in Pakistan, where, for example, recent farm-level data from Sindh, indicates that irrigated wheat output per hectare varies from 0.5 to 5.4 tons across farms. Looks at the central goal of agricultural policy in the country, viz. improving and sustaining productivity, narrowing the existing productivity gaps, and enhancing resource use efficiencies to meet food requirements of a rapidly growing population. |
| Tipo: Report |
Palavras-chave: Irrigated farming; Wheat; Productivity; Performance evaluation; Water management; Cropping systems; Water supply; Soil properties; Models; Pakistan; Lower Indus Basin; Agribusiness; Agricultural Finance; Crop Production/Industries; Environmental Economics and Policy; Farm Management; Production Economics; Productivity Analysis. |
| Ano: 2000 |
URL: http://purl.umn.edu/53023 |
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| Farrell, Terence C.. |
| Economic benefits that arise from conservation farming practices need to be assessed over several years to account for improvements in soil structure and nutrient levels. A gross margin model was used to assess benefits over the eight-year period 1999-2006 for 12 regions in the central west of NSW. The annual benefits from improved soil structure ranged from $2.46 to $12.82 per hectare (ha). A reduction in tractor power produced annual savings in the range of $0.60 to $4.05 per ha. The cost of soil compaction by livestock grazing on crop areas ranged from $3.41 to $14.90 per ha. The break-even time to pay back costs for the conversion of machinery for no-till seeding was two to three seasons. |
| Tipo: Conference Paper or Presentation |
Palavras-chave: No-till; Conservation; Farming; Tillage; Cropping systems; Environmental Economics and Policy; Farm Management. |
| Ano: 2008 |
URL: http://purl.umn.edu/6177 |
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| Registros recuperados: 155 | |
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