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Registros recuperados: 8
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A new N index to assess nitrogen dynamics in potato (Solanum tuberosum L.) production systems of Bolivia Agrociencia
Saavedra,Ana K.; Delgado,Jorge A.; Botello,Ruben; Mamani,Pablo; Alwang,Jeffrey.
Bolivia is South America's poorest country, with over 80 % of the rural population under the poverty line and agricultural productivity is closely inversely correlated with poverty in rural Bolivia. Potato (Solanum tuberosum L.) is one of the most important crops for food security in Bolivia, where it is grown with traditional methods, and national-level yields are low. Traditional management of potato involves use of organic amendments (animal manures) to supply N. Enhanced N management has the potential to raise potato yields and reduce rural poverty, yet there is a lack of information about improving nitrogen management practices in potato production areas where traditional systems predominate. A N index for traditional agricultural systems in Bolivia...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Food security; High altitude cropping systems; Nitrate leaching; Solanum tuberosum L.; Sustainable system.
Ano: 2014 URL: http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1405-31952014000700001
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An Application of Mixed Logit Estimation in the Analysis of Producers’ Stated Preferences AgEcon
Kipperberg, Gorm; Bond, Craig A.; Hoag, Dana L..
This paper analyzes Colorado Corn producers’ preferences over both private- and environmental public-good production system attributes. Current production practices are characterized by intensive water and chemical use, resulting in non-point source pollution to water bodies as well as soil erosion problems. Data from a stated preference survey are employed to analyze key attributes of experimentally configured irrigation systems, proposed as alternatives to current practices. Panel mixed logit estimations find positive preferences for profit, risk reduction, and, importantly, systems with less environmental impact in terms of nitrate leaching and soil erosion. The results also find presence of significant preference heterogeneity and a complementary...
Tipo: Working or Discussion Paper Palavras-chave: Agricultural production; Profit-maximization; Environment; Mixed logit; Stated preference; Attribute part-worth; Nitrate leaching; Soil erosion; Risk; Crop Production/Industries; C10; D62; Q12; Q15; Q51.
Ano: 2008 URL: http://purl.umn.edu/108719
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Combined pig slurry and mineral fertilization for corn cultivation BABT
Prior,Maritane; Sampaio,Silvio César; Nóbrega,Lúcia Helena Pereira; Opazo,Miguel Angel Uribe; Dieter,Jonhatan; Pegoraro,Thaisa.
The objective of this work was to evaluate the environmental effects of the use of pig slurry to irrigate the corn crop grown in a typical Red Distroferric Latosol and in leachate composition. Twenty four lysimeters, filled with soil, in a protected environment, received five doses of pig slurry (0; 112.5; 225; 337.5 and 450 m³ ha-1 per growing cycle) combined with two mineral fertilization doses (50 and 75% of the recommended dose - 80 kg ha-1of nitrogen). Corn height and yield were evaluated, as well as nutrients in the soil and in leachate. From the results obtained in the first year of experiment, it was concluded that the concentrations of nitrate increased by increase of pig slurry application, and thus, it would be necessary to develop further...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Nitrate leaching; Nutrients cycling; Zea mays L.
Ano: 2013 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132013000200020
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Evaluation of EPIC for Three Minnesota Cropping Systems AgEcon
Chung, S.W.; Gassman, Philip W.; Huggins, David R.; Randall, G.W..
The Erosion Productivity Impact Calculator (EPIC) model was tested using four years of field data collected at a site near Lamberton, Minnesota, under three different crop rotations: continuous corn (Zea mays L.) or CC, soybean (Glycine max L.)-corn (SC), continuous alfalfa (Medicago sativa L.) or CA. The model was evaluated by comparing measured versus predicted subsurface drainage flow (tile flow), nitrate-nitrogen (NO3-N) loss in tile flow, residual NO3-N in the soil profile, crop N uptake, and yield. Initially, EPIC was run using standard Soil Conservation Service (SCS) runoff curve numbers (CN2) suggested for the soil type at the site. Two different SC runs were performed with a nitrogen fixation parameter denoted as parm(7) set at either 1.0 or 0.3,...
Tipo: Working or Discussion Paper Palavras-chave: Modeling; Water quality; Crop rotation; Tile drainage; Nitrate leaching; Fertilizer; Crop Production/Industries.
Ano: 2000 URL: http://purl.umn.edu/18479
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Evaluation of fertilization with uncoated urea and 3,4-dimethylpyrazole phosphate (DMPP)-coated urea on nitrogen leaching and rose (Rosa spp.) yield Chilean J. Agric. Res.
García-Castro,Alexandra; Restrepo-Díaz,Hermann.
The negative impact of N over-fertilization has acquired importance in rose (Rosa spp.) growers in Colombia. The nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) has been considered a valuable alternative to diminish the N losses by leaching and to enable more efficient N use efficiency in crops. The objective of the present work was to study the effect of DMPP on the mineral N (NH4+- N and NO3--N) content in soil and water leaching, and physiological characteristics of rose plants. A greenhouse experiment was performed for 10 wk. Four-year-old 'Charlotte' rose cultivars grafted on 'Natal Briar' were grown in soil and fertirrigated daily with a complete nutrient solution containing 170 mg N L-1. Two N fertilizers (uncoated urea [UA], and urea...
Tipo: Journal article Palavras-chave: Chlorophyll fluorescence; Leaf nitrogen concentration; Nitrate leaching; Nitrogen use efficiency.
Ano: 2013 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392013000200011
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Nitrate and ammonium in soil solution in tobacco management systems Rev. Bras. Ciênc. Solo
Kaiser,Douglas Rodrigo; Reinert,Dalvan José; Reichert,José Miguel; Streck,Carlos Arnoldo; Pellegrini,André.
Tobacco farmers of southern Brazil use high levels of fertilizers, without considering soil and environmental attributes, posing great risk to water resources degradation. The objective of this study was to monitor nitrate and ammonium concentrations in the soil solution of an Entisol in and below the root zone of tobacco under conventional tillage (CT), minimum tillage (MT) and no-tillage (NT). The study was conducted in the small-watershed Arroio Lino, in Agudo, State of Rio Grande do Sul, Brazil. A base fertilization of 850 kg ha-1 of 10-18-24 and topdressing of 400 kg ha-1 of 14-0-14 NPK fertilizer were applied. The soil solution was sampled during the crop cycle with a tension lysimeter equipped with a porous ceramic cup. Ammonium and nitrate...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Nitrate leaching; Agricultural watershed; Water contamination; Tension lysimeter.
Ano: 2010 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832010000200011
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POLICY IMPLICATIONS ON THE REDUCTION OF NITROGEN FERTILIZER USE ON NON-IRRIGATED CORN-WINTER WHEAT PRODUCTION IN NORTH ALABAMA AgEcon
Joseph, Barbara A.; Jones, Hezekiah; Befecadu, Joseph.
Environmental and economic effects of nitrogen fertilizer reduction on North Alabama small farms are evaluated using GPFARM. GPFARM incorporates climate, soil data and management practices to simulate science and economic analysis for a farm/ranch management unit. Nitrate leaching, crop yield and profitability are evaluated and presented under different policy scenarios. Key words: nitrate leaching, profitability, management unit, GPFARM
Tipo: Conference Paper or Presentation Palavras-chave: Nitrate leaching; Profitability; Management unit; GPFARM; Crop Production/Industries.
Ano: 2003 URL: http://purl.umn.edu/35183
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WILL FARMERS USE SAFER PESTICIDES? AgEcon
Owens, Nicole N.; Swinton, Scott M.; van Ravenswaay, Eileen O..
Virtually all technology adoption studies are conducted ex post, yet policy makers often need to assess the likely level of adoption before the technology is introduced. This study uses data from a contingent valuation survey of Michigan corn growers to assess what factors would influence the adoption of two safer corn herbicides, one that is not carcinogenic and one that does not leach. Results indicate that price, risk perception, and sources of pest control information are all important. This suggests that public policies designed to change perceptions and improve information dissemination may encourage voluntary use of more environmentally friendly technologies.
Tipo: Working or Discussion Paper Palavras-chave: Atrazine; Cancer risk; Contingent valuation; Herbicides; Nitrate leaching; Public policy; Technology adoption; Crop Production/Industries.
Ano: 1997 URL: http://purl.umn.edu/11577
Registros recuperados: 8
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