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Search Results: 1 - 10 of 50647 matches for " Antonio Luiz;Frizzone "
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Balance hídrico ciclico y secuencial : estimación de almacenamiento de agua en el suelo
Dourado-Neto Durval,García y García Axel,Fancelli Antonio Luiz,Frizzone José Antonio
Scientia Agricola , 1999,
Abstract: El presente trabajo tiene por objetivo presentar un modelo mecanístico para estimar el almacenamiento de agua en el suelo, con el propósito de prever el rendimiento agrícola para cultivos anuales no fotosensibles. El movimiento y la retención de agua en el sistema agrícola, son los atributos de interés en el estudio. El rendimiento agrícola depende de los procesos básicos de fotosíntesis y respiración. También, el rendimiento depende de la especie vegetal, nutrición de la planta, energia disponible, población de plantas, plantas da inas y población de parásitos, principalmente. Además, la evapotranspiración actual también depende de los mismos atributos y procesos. Por lo tanto, la hipótesis base del modelo es que es posible estimar el rendimiento estimando la evapotranspiración. Conociendo empíricamente el comportamiento de pérdida de agua del suelo, sin conocer todos los atributos y las complejas interrelaciones que lo gobiernan, el modelo cosenoidal fue propuesto para estimar el almacenamiento de agua en el suelo. El modelo cosenoidal fue comparado con otros modelos y se concluye que el mismo estima mejor el almacenamiento de agua en el suelo.
Balance hídrico ciclico y secuencial: estimación de almacenamiento de agua en el suelo
Dourado-Neto, Durval;García y García, Axel;Fancelli, Antonio Luiz;Frizzone, José Antonio;Reichardt, Klaus;
Scientia Agricola , 1999, DOI: 10.1590/S0103-90161999000300005
Abstract: the objective of this paper is to present a mechanistic model to estimate the available soil water storage to forecast yield for nonphotosensitive annual crops. in this study, concern is devoted to the movement and retention of water within the agricultural system. crop yield depends upon the basic processes of photosynthesis and respiration. the yield also depends on crop species, crop nutrition, available energy, plant population, weeds and parasite populations, mainly. in addition, actual evapotranspiration also depends on the same attributes and processes. therefore, the basic hypothesis of this model is that it is possible to forecast crop yield with estimates of actual evapotranspiration. knowing empirically the process of soil water loss, but without knowing all attributes and their complex relations ruling this behavior, a cosine model was established to estimate available soil water storage. the cosine model was constructed and checked together with other models and the conclusion is that the cosine model best estimates soil water storage.
Produtividade do feijoeiro sob diferentes uniformidades de distribui??o de água na superfície e na subsuperfície do solo
Frizzone, José A.;Rezende, Roberto;Gon?alves, Antonio C. A.;Helbel Júnior, Celso;
Engenharia Agrícola , 2007, DOI: 10.1590/S0100-69162007000300010
Abstract: aiming to evaluate the effect of irrigation depth and soil moisture uniformity on dry bean yield, an experiment was conducted with the cultivar iapar 57. water was applied on soil surface at four uniformity levels with the same irrigation depth, imposed by four sprinklers spaced at 12 x 12 m; 18 x 18 m; 18 x 24 m, and 24 x 24 m. spatial distribution analyses of the irrigation depth, soil moisture and grain yield data were proceeded with exploratory data analysis techniques based on simplified box-plot graphics, which only represent the median, minimal, and maximal values. it was verified that the quality of irrigation affected the soil moisture uniformity, causing effect also on dry bean yield. the maximum uniformity of water distribution did not relate with the highest yield.
Probabilidade de ocorrência da evapotranspira??o de referência na regi?o de Dourados, MS
Fietz, Carlos Ricardo;Frizzone, José Antonio;Folegatti, Marcos Vinícius;Pinto, José Maria;
Ciência Rural , 1997, DOI: 10.1590/S0103-84781997000200006
Abstract: the aim of this work was to study the distribution accumulative probability ocorrence of reference evapotranspiration (eto) for designing irrigation systems in dourados, mato grosso do sul state. the eto estimated by penman equation considering climatic parameters of 16 years was accumulated for periods of 5, 10, 15, 20 and 30 days. the maximum annual values resulted in series that were adjusted to normal, log-normal and beta distribuition. there was a decreasing of daily eto as the accumulated period increased. the three distributions adjusted to all accumulated periods. throught the accumulated normal distribution it was generated values of eto for periods of 2, 3, 4, 5, 8, 10, 12 and 14 years. these values of eto multiplied by the crop coefficient may be used as the main parameter to design irrigation systems in dourados region.
Aduba??o nitrogenada do milho em um sistema de irriga??o por aspers?o em linha
Mendon?a, Fernando Campos;Medeiros, Roberto Dantas de;Botrel, Tarlei Arriel;Frizzone, José Antonio;
Scientia Agricola , 1999, DOI: 10.1590/S0103-90161999000500004
Abstract: the nitrogen effect on a corn crop, applied by fertigation through a line source sprinkler system was evaluated, using urea [co(nh2)2] as nitrogen source. the line source sprinkler system had three pipelines with five sprinklers each. the sprinkler spacing was six meters, and the lateral spacing, twelve meters. fertigation and irrigaiton were made by the external lines, and the central line was used only for irrigation. the total water depth applied during the crop cicle was 650 mm. this water application was made in an uniform way along the experimental area, and nitrogen levels decreased along the perpendicular direction to the central sprinkler line, ranging from 353 to 30 kg n/ha. results showed that different nitrogen levels affected the following crop production factors: plant height, corn cob inserction height, corn yield, corn cob length, thousand grain weight, and nitrogen contain of grains. the point of maximum grain yield (7634 kg/ha) was estimated by a crop production function in relation to nitrogen levels. the maximum grain yield was obtained with 262.6 kg n/ha.
Co2 and irrigation in relation to yield and water use of the bell pepper crop
Rezende, Fátima Concei??o;Frizzone, José Antonio;Oliveira, Ricardo Ferraz de;Pereira, Anderson Soares;
Scientia Agricola , 2003, DOI: 10.1590/S0103-90162003000100002
Abstract: greenhouse production of vegetables is widely used throughout the world. elevated carbon dioxide (co2) concentrations in these closed environments can increase net photosynthesis and yield. the objective of this study was to determine the effects of atmospheric co2 enrichment and water supply on the growth of potted bell pepper (capsicum annuum l.) plants, cultivated under controlled environmental conditions. co2 was applied daily, and its distribution was monitored above plant rows through micro pipes located at 3.0 m height. a drip irrigation system with one dripper per plant was used to irrigate the plants. different volumes of irrigation water, representing fractions of the water volume (vet) consumed by pot plants growing under no water stress conditions (0.5vet, 0.65vet, 1.0vet, and 1.35vet) with four replications, were evaluated under four different co2 levels (atmospheric concentration of 367, 600, 800, and 1000 mmol mol-1). total fresh fruit mass, average number of fruits, and water use efficiency were recorded. for the water deficit treatments, the greatest fresh fruit mass was obtained for the highest co2 level environment. however, for treatments that received water volumes equal or greater than the evapotranspiration rate, the greatest total fresh fruit mass was observed at the 600 mmol mol-1 of co2 environment. the yield increase due to co2 was represented by increase in fruit weight and not in fruit number. water use efficiency increased in relation to the amount of water applied and it was highest at 600 mmol mol-1 co2 concentration.
Estratégias ótimas de irriga o para a cultura da melancia
Andrade Júnior Aderson Soares de,Frizzone José Antonio,Bastos Edson Alves,Cardoso Milton José
Pesquisa Agropecuária Brasileira , 2001,
Abstract: O trabalho teve como objetivo determinar estratégias ótimas de irriga o para a cultura da melancia (Citrullus lanatus Thumb. Mansf.), considerando a água como fator limitante da produ o e diferentes valores para o pre o do produto e custos da energia elétrica. Utilizou-se uma fun o de produ o quadrática e fun o de custo linear obtidas para as condi es edafoclimáticas dos Tabuleiros Costeiros do Piauí. A irriga o com déficit proporcionou as maiores rendas líquidas, com significativa economia de água, no intervalo de varia o de pre os do produto de US$ 0,05 kg-1 a US$ 0,35 kg-1, nas três formas de tarifa o da energia elétrica. Acima desse intervalo, deve-se utilizar a lamina que maximiza a produ o de frutos.
Viabilidade econ mica do cultivo irrigado do feij o-caupi no Estado do Piauí = Economic feasibility of cowpea irrigation in Piauí State
Francisco Edinaldo Pinto Mousinho,Aderson Soares de Andrade Júnior,José Antonio Frizzone
Acta Scientiarum : Agronomy , 2008,
Abstract: O objetivo deste trabalho foi avaliar a viabilidade econ mica da irriga o do feij o-caupi no Estado do Piauí. Realizaram-se balan os hídricos de cultivo em escala diária, utilizando o método de Thornthwaite e Mather (1955), para 165 locais, considerando-se 12datas de semeadura e capacidade de água disponível no solo (CAD) de 20, 40 e 60 mm. As receitas líquidas foram estimadas com uma probabilidade de ocorrência de 75%, sendo posteriormente, especializadas para o Estado do Piauí. O cultivo irrigado do feij o- caupi, no Piauí, mostrou-se economicamente viável para todas as datas de semeadura, independentemente da CAD utilizada, com as receitas líquidas variando para as diversas regi es do Estado, em fun o da época de semeadura e da CAD. Considerando-se uma estratégia de planejamento em nível estadual, a semeadura em 1o de fevereiro foi a que se mostrou mais favorável, pois proporcionou a obten o de maiores valores de receitas líquidas, bem como maiores áreas do Estado ocupadas por estas. The objective of this work was to evaluate the economic feasibility of cowpea irrigation in Piauí State, Brazil. Water balances were carried out on a daily basis using the Thornthwaite and Mather(1955) method, for 165 sites, considering twelve sowings dates and available water capacity in the soil of 20, 40 and 60 mm. The net revenues were estimated with a probability of occurrence of 75%, later being spatialized to Piauí State. Cowpea irrigation was shown toeconomically viable for all sowing dates, irrespective of the available water capacity. Net revenues varied among several regions of the State, in function of the sowing date and available water capacity in the soil. Considering a planning strategy for Piaui State, sowing on February, 1 was shown to be most favorable, because it enabled higher net revenue values, covering larger areas of the State.
Aduba o nitrogenada do milho em um sistema de irriga o por aspers o em linha
Mendon?a Fernando Campos,Medeiros Roberto Dantas de,Botrel Tarlei Arriel,Frizzone José Antonio
Scientia Agricola , 1999,
Abstract: Foi avaliado o efeito do nitrogênio na cultura do milho através da fertirriga o, utilizando um sistema de irriga o por aspers o em linha e uréia como fonte de N. O sistema de aspers o em linha foi constituído por 3 linhas com cinco aspersores cada uma, cujo espa amento foi de 6 metros entre si e 12 metros entre as linhas. O fertilizante foi aplicado nas linhas externas e a linha central aplicou apenas água. A lamina de água total aplicada durante o ciclo foi de 650 mm. Essa aplica o foi feita de forma uniforme, e as doses de nitrogênio foram decrescentes na dire o perpendicular às linhas externas de aspersores, variando de 353 a 30 kg/ha de N. Os resultados obtidos mostraram que as diferentes dosagens de nitrogênio afetaram os seguintes parametros medidos: altura das plantas, altura de inser o das espigas, produtividade, comprimento das espigas, peso de mil gr os e teor de nitrogênio nos gr os. O ponto de máxima produtividade de gr os (7634 kg/ha) foi estimado através de uma fun o de produ o da cultura em rela o ao fator doses de nitrogênio. A máxima produtividade estimada pode ser atingida com uma dose de 262,6 kg/ha de N.
Co2 and irrigation in relation to yield and water use of the bell pepper crop
Rezende Fátima Concei??o,Frizzone José Antonio,Oliveira Ricardo Ferraz de,Pereira Anderson Soares
Scientia Agricola , 2003,
Abstract: Greenhouse production of vegetables is widely used throughout the world. Elevated carbon dioxide (CO2) concentrations in these closed environments can increase net photosynthesis and yield. The objective of this study was to determine the effects of atmospheric CO2 enrichment and water supply on the growth of potted bell pepper (Capsicum annuum L.) plants, cultivated under controlled environmental conditions. CO2 was applied daily, and its distribution was monitored above plant rows through micro pipes located at 3.0 m height. A drip irrigation system with one dripper per plant was used to irrigate the plants. Different volumes of irrigation water, representing fractions of the water volume (Vet) consumed by pot plants growing under no water stress conditions (0.5Vet, 0.65Vet, 1.0Vet, and 1.35Vet) with four replications, were evaluated under four different CO2 levels (atmospheric concentration of 367, 600, 800, and 1000 mumol mol-1). Total fresh fruit mass, average number of fruits, and water use efficiency were recorded. For the water deficit treatments, the greatest fresh fruit mass was obtained for the highest CO2 level environment. However, for treatments that received water volumes equal or greater than the evapotranspiration rate, the greatest total fresh fruit mass was observed at the 600 mumol mol-1 of CO2 environment. The yield increase due to CO2 was represented by increase in fruit weight and not in fruit number. Water use efficiency increased in relation to the amount of water applied and it was highest at 600 mumol mol-1 CO2 concentration.
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