Home Itens selecionados Provedores de dados OAI Créditos Sobre Ajuda

			Busca avançada
	Provedor de dados AgEcon (5) Thai Agricultural (1) Scientia Agricola (1) REA (1) Autor Abele, Steffen (1) Bocca,Felipe Ferreira (1) Cooper, Joseph C. (1) Debnath, Deepayan (1) Diagne, Aliou (1) Diagne, Mandiaye (1) English, Burton C. (1) Epplin, Francis M. (1) Krirk Pannangpetch (1) Langemeier, Michael R. (1) Li, Man (1) Mahajanashetti, S.B. (1) PELOIA,PAULO R. (1) Peloia,Paulo Rodrigues (1) Preecha Kapetch (1) RODRIGUES,LUIZ H. A. (1) Reimer, Jeffrey J. (1) Roberts, Roland K. (1) Rodrigues,Luiz Henrique Antunes (1) Schnitkey, Gary D. (1) Mais... Palavra-chave Yield variability (8) Crop Production/Industries (3) Agricultural and Food Policy (2) Corn (2) Food Security and Poverty (2) International Relations/Trade (2) Land Economics/Use (2) Regression tree (2) Risk and Uncertainty (2) Africa (1) Agricultural trade (1) Climate change (1) Clustering (1) Crop insurance (1) Crops (1) Data mining (1) EPIC (1) Geography (1) Grains (1) Knowledge discovery (1) Mais... Tipo do documento Conference Paper or Presentation (2) Info:eu-repo/semantics/article (2) Presentation (2) Collection (1) Journal Article (1) Ano 2019 (1) 2016 (1) 2012 (3) 2009 (2) 1999 (1) País United States (5) Brazil (2) Thailand (1) Idioma Inglês (7) Thailandês (1)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 8 Primeira ... 1 ... Última Identification of commercial blocks of outstanding performance of sugarcane using data mining REA PELOIA,PAULO R.; RODRIGUES,LUIZ H. A.. ABSTRACT In order to achieve more efficient agricultural production systems, studies relating to the patterns of influence factors on commercial blocks of outstanding performance can be performed to assist management practices. The performance is considered to be the difference between the yield of a given block and the average yield of the homogeneous group that it belongs to. The methods available to identify these outstanding blocks are usually subjective. The aim of this study was to propose an objective and repeatable approach to identify outstanding performance blocks. The proposed approach consisted of performance determination, using regression trees, and the classification of these blocks by k-means clustering. This approach was illustrated using... Tipo: Info:eu-repo/semantics/article Palavras-chave: Clustering; Regression tree; Yield variability. Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162016000500895 Managing Expected Switchgrass Biomass Yield Variability by Strategically Selecting Land to Lease AgEcon Debnath, Deepayan; Stoecker, Arthur L.; Epplin, Francis M.. Biorefineries that plan to use switchgrass exclusively will have to account for year-to-year variability in feedstock production. The objective of this research is to determine the quantity, class, and location of land to lease for switchgrass production to provide for the needs of a biorefinery. The firm could elect to lease land based on average switchgrass yields or to lease to attempt to insure that even in the worst case (based on historical data) production year the area leased will produce sufficient feedstock to fully provide for the needs of the biorefinery. EPIC was used to generate empirical distributions of switchgrass biomass yields for three land classes for each of 30 counties. Mathematical programming was used to address the objectives and... Tipo: Presentation Palavras-chave: EPIC; Mathematical programming; Switchgrass; Yield variability; Crop Production/Industries; Land Economics/Use; Risk and Uncertainty; Q42; Q12. Ano: 2012 URL: http://purl.umn.edu/124230 Constructing Farm Level Yield Densities from Aggregated Data: Analysis and Comparison of Approaches AgEcon Cooper, Joseph C.; Langemeier, Michael R.; Schnitkey, Gary D.; Zulauf, Carl R.. Yield variability can be significantly higher at the farm level than at more aggregated levels, including the county. However, due to a dearth of available farm level data, much stochastic analysis involving farm yields utilizes more aggregated yield data as a proxy for the farm level. We empirically evaluate farm-level variability using longitudinal farm level data sets available from the Kansas Farm Management Association and the Illinois Farm Business and Farm Management Association. For corn, soybeans, and wheat, we compare the farm level yield variability obtained from this data to that inferred from Federal crop insurance premiums. The farm management data exhibit lower yield variability than are implied by the crop insurance premiums. Tipo: Conference Paper or Presentation Palavras-chave: Yield variability; Crop insurance; Corn; Wheat; Soybeans; Agricultural and Food Policy; Crop Production/Industries; Research Methods/ Statistical Methods; Risk and Uncertainty. Ano: 2009 URL: http://purl.umn.edu/49216 SPATIAL BREAK-EVEN VARIABILITY FOR CUSTOM HIRE VARIABLE RATE TECHNOLOGY ADOPTION AgEcon Mahajanashetti, S.B.; English, Burton C.; Roberts, Roland K.. A theoretical model identified ranges of spatial variability required within multiple-land-class fields for economically viable variable rate technology (VRT) and the spatial variability required for maximum return to VRT. An example illustrated that return to VRT and the viable range of spatial variability increased for higher corn and nitrogen prices. Tipo: Conference Paper or Presentation Palavras-chave: Precision farming; Site-specific farming; Nitrogen; Corn; Spatial variability; Yield variability; Profit function; Land Economics/Use; Resource /Energy Economics and Policy. Ano: 1999 URL: http://purl.umn.edu/21676 Yield Variability and Agricultural Trade AgEcon Reimer, Jeffrey J.; Li, Man. We examine how changes in yield variability affect the welfare of cereal grain and oilseed buyers and producers around the world. We simulate trade patterns and welfare for 21 countries with a Ricardian trade model that incorporates bilateral trade costs and crop yield distributions. The model shows that world trade volumes would need to increase substantially if crop yield variability were to rise. Net welfare effects, however, are moderate so long as countries do not resort to policies that inhibit trade, such as export restrictions or measures to promote self-sufficiency in crops. Low-income countries suffer the most from increases in yield variability, due to higher bilateral trade costs and lower-than-average productivity. Tipo: Journal Article Palavras-chave: Crops; Geography; Grains; Trade liberalization; Yield variability; Crop Production/Industries; Food Security and Poverty; International Relations/Trade. Ano: 2009 URL: http://purl.umn.edu/55543 Agricultural trade for food security in Africa: A Ricardian model approach AgEcon Diagne, Mandiaye; Abele, Steffen; Diagne, Aliou; Seck, Papa Abdoulaye. Regionalism and food security is a relatively neglected topic with very limited literature. We use a Ricardian trade model with multiple goods and countries which embeds a structure of gravity equation and yield variability. Our study shows that integration with African markets of staple foods is associated with higher growth, underpinning the need for growth strategies to emphasize scaling up and diversifying exports within Africa. Africa needs to unlock its high potential untapped land and fill up the yield gap. We found as well that enhanced competitiveness and reduced barriers to trade are the two critical areas of action. Tipo: Presentation Palavras-chave: Ricardian model; Yield variability; Agricultural trade; Staple foods; Africa; Agricultural and Food Policy; Food Security and Poverty; International Relations/Trade. Ano: 2012 URL: http://purl.umn.edu/123842 Identification of patterns for increasing production with decision trees in sugarcane mill data Scientia Agricola Peloia,Paulo Rodrigues; Bocca,Felipe Ferreira; Rodrigues,Luiz Henrique Antunes. ABSTRACT: Sugarcane mills in Brazil collect a vast amount of data relating to production on an annual basis. The analysis of this type of database is complex, especially when factors relating to varieties, climate, detailed management techniques, and edaphic conditions are taken into account. The aim of this paper was to perform a decision tree analysis of a detailed database from a production unit and to evaluate the actionable patterns found in terms of their usefulness for increasing production. The decision tree revealed interpretable patterns relating to sugarcane yield (R2 = 0.617), certain of which were actionable and had been previously studied and reported in the literature. Based on two actionable patterns relating to soil chemistry, intervention... Tipo: Info:eu-repo/semantics/article Palavras-chave: Data mining; Yield variability; Regression tree; Knowledge discovery. Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162019001400281 ผลกระทบของการเปลี่ยนแปลงสภาพภูมิอากาศต่อการผลิตอ้อยในภาคตะวันออกเฉียงเหนือของประเทศไทย: พื้นที่ศึกษา จังหวัดกาฬสินธุ์ Thai Agricultural Preecha Kapetch; Krirk Pannangpetch. Climate change can directly affect crop production due to the increases of CO2 and temperature, and indirectly via weather variability especially rainfall. Sugarcane is important crop for Thailand, and large proportion are planted in Northeast of Thailand. Therefore this investigation is conducted to evaluate the impacts of climate change on yield of sugarcane in this region from 2010 to 2049, using ECHAM weather data downscale to 20x20 km by PRECIS as input to CANEGRO crop model in DSSAT program. Results showed that climate change has small effect on long term changes in sugarcane production. However average yield is highly variable, both spatially and temporally. Spatial variability is largely due to both soil and weather while temporal variability is... Tipo: Collection Palavras-chave: Sugarcane; Climate change; Yield variability; อ้อย; ความแปรปรวนของผลผลิตอ้อย; การเปลี่ยนแปลงของอากาศ; การผลิตอ้อย; ผลผลิต; ภาคตะวันออกเฉียงเหนือ; จ.กาฬสินธุ์. Ano: 2012 URL: http://anchan.lib.ku.ac.th/agnet/handle/001/5323 Registros recuperados: 8 Primeira ... 1 ... Última

Empresa Brasileira de Pesquisa Agropecuária - Embrapa Todos os direitos reservados, conforme Lei n° 9.610 Política de Privacidade Área restrita		Embrapa Parque Estação Biológica - PqEB s/n° Brasília, DF - Brasil - CEP 70770-901 Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC: https://www.embrapa.br/fale-conosco