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Search Results: 1 - 10 of 175469 matches for " Anamari Viegas de Araujo;Molin "
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Mapeamento do índice de vegeta??o da diferen?a normalizada em lavoura de algod?o
Motomiya, Anamari Viegas de Araujo;Molin, José Paulo;Motomiya, Wagner Rogerio;Rojo Baio, Fábio Henrique;
Pesquisa Agropecuária Tropical , 2012, DOI: 10.1590/S1983-40632012000100016
Abstract: the remote sensing data obtained at field level can provide detailed information about the variability of biophysical parameters related to yield over large areas, and present potential for monitoring these parameters throughout the crop development cycle. this study aimed to map the spatial variability of the normalized difference vegetation index (ndvi) and its components in two commercial cotton (gossipium hirsutum l.) fields, by using an active optical sensor at the ground level. data were collected with the aid of an optical sensor installed in a self-propelled agricultural sprayer. a gps receiver was connected to the sensor, in order to obtain the coordinates of the sampling points. the readings were performed in rows spaced 21.0 m apart by the sensor installed on a vehicle, during the spraying operation, and data analyzed by using the classical statistics and geostatistics. spatial distribution maps of the variables were generated by kriging interpolation. it was observed a higher spatial variability of ndvi and spectral reflectance of vegetation in the region of near infrared (nir) (880 nm) and visible infrared (590 nm) in the crop with higher physiological stress, due to the brown bug [scaptocoris castanea (hem.: cydnidae)] attack, when compared to the healthy one.
Test procedure for variable rate fertilizer on coffee = Método para avalia o de aplica o de fertilizantes em taxa variável em café
José Paulo Molin,Anamari Viegas de Araujo Motomiya,Flavia Roncato Frasson,Gustavo Di Chiacchio Faulin
Acta Scientiarum : Agronomy , 2010,
Abstract: The objective was to develop and test a procedure for applying variable rates of fertilizers and evaluate yield response in coffee (Coffea arabica L.) with regard to the application of phosphorus and potassium. The work was conducted during the 2004 season in a 6.4 ha field located in central S o Paulo state. Two treatments were applied with alternating strips of fixed and variable rates during the whole season: one following the fertilizing procedures recommended locally, and the other based on a grid soil sampling. A prototype pneumatic fertilizer applicator was used, carrying two conveyor belts, one foreach row. Harvesting was done with a commercial harvester equipped with a customized volumetric yield monitor, separating the two treatments. Data were analyzed based on geostatistics, correlations and regressions. The procedure showed to be feasible and effective. The area that received fertilizer applications at a variable rate showed a 34% yield increase compared to the area that received a fixed rate. The variable rate fertilizer resulted in a savings of 23% in phosphate fertilizer and a 13% increase in potassium fertilizer, when compared to fixed rate fertilizer. Yield in 2005, the year after the variable rate treatments, still presented residual effect from treatments carried out during the previous cycle. O objetivo foi desenvolver um procedimento para avaliar a resposta daprodutividade de café (Coffea arabica L.), a partir da aplica o de fósforo e potássio. O trabalho foi conduzido durante o ciclo produtivo do ano de 2004 em um talh o de 6,4 ha localizado na regi o central do Estado de S o Paulo. Foram aplicados dois tratamentos emlinhas alternadas de plantas com doses fixas e variadas, um seguindo procedimentos e recomenda es locais e o outro com base na amostragem de solo em grade. Para a aplica o dos fertilizantes, foi utilizado o protótipo de uma adubadora com duas esteiras independentes, uma para cada linha de plantas. A colheita foi executada com uma colhedoracomercial equipada com monitor de produtividade volumétrico. Os dados foram analisados utilizando-se a geoestatística, correla es e regress es. O método mostrou-se efetivo e de fácil execu o. A área que recebeu fertilizantes aplicados em doses variadas apresentouprodutividade 34% maior se comparada com a área que recebeu aduba o em taxa fixa. A aplica o em taxa variada resultou em economia de 23% de fósforo e aumento de 13% no consumo de potássio quando comparada com a aplica o dos fertilizantes em taxa fixa. A produtividade de café em 2005, no ciclo seguinte ao experimento,
Test procedure for variable rate fertilizer on coffee
Molin, José Paulo;Motomiya, Anamari Viegas de Araujo;Frasson, Flavia Roncato;Faulin, Gustavo Di Chiacchio;Tosta, Wanderson;
Acta Scientiarum. Agronomy , 2010, DOI: 10.4025/actasciagron.v32i4.5282
Abstract: the objective was to develop and test a procedure for applying variable rates of fertilizers and evaluate yield response in coffee (coffea arabica l.) with regard to the application of phosphorus and potassium. the work was conducted during the 2004 season in a 6.4 ha field located in central s?o paulo state. two treatments were applied with alternating strips of fixed and variable rates during the whole season: one following the fertilizing procedures recommended locally, and the other based on a grid soil sampling. a prototype pneumatic fertilizer applicator was used, carrying two conveyor belts, one for each row. harvesting was done with a commercial harvester equipped with a customized volumetric yield monitor, separating the two treatments. data were analyzed based on geostatistics, correlations and regressions. the procedure showed to be feasible and effective. the area that received fertilizer applications at a variable rate showed a 34% yield increase compared to the area that received a fixed rate. the variable rate fertilizer resulted in a savings of 23% in phosphate fertilizer and a 13% increase in potassium fertilizer, when compared to fixed rate fertilizer. yield in 2005, the year after the variable rate treatments, still presented residual effect from treatments carried out during the previous cycle.
Spatial variability of soil fertility and its relationship with seed physiological potential in a soybean production area
Mondo, Vitor Henrique Vaz;Gomes Junior, Francisco Guilhien;Pinto, Taís Leite Ferreira;Marchi, José Luis de;Motomiya, Anamari Viegas de Araújo;Molin, José Paulo;Cicero, Silvio Moure;
Revista Brasileira de Sementes , 2012, DOI: 10.1590/S0101-31222012000200002
Abstract: the correlation of soil fertility x seed physiological potential is very important in the area of seed technology but results published with that theme are contradictory. for this reason, this study to evaluate the correlations between soil chemical properties and physiological potential of soybean seeds. on georeferenced points, both soil and seeds were sampled for analysis of soil fertility and seed physiological potential. data were assessed by the following analyses: descriptive statistics; pearson's linear correlation; and geostatistics. the adjusted parameters of the semivariograms were used to produce maps of spatial distribution for each variable. organic matter content, mn and cu showed significant effects on seed germination. most variables studied presented moderate to high spatial dependence. germination and accelerated aging of seeds, and p, ca, mg, mn, cu and zn showed a better fit to spherical semivariogram: organic matter, ph and k had a better fit to gaussian model; and v% and fe showed a better fit to the linear model. the values for range of spatial dependence varied from 89.9 m for p until 651.4 m for fe. these values should be considered when new samples are collected for assessing soil fertility in this production area.
Utiliza??o de sensor óptico ativo para detectar deficiência foliar de nitrogênio em algodoeiro
Motomiya, Anamari V. de A.;Molin, José P.;Chiavegato, Ederaldo J.;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2009, DOI: 10.1590/S1415-43662009000200005
Abstract: this study aimed to evaluate, under field conditions, the effect of variation in levels of nitrogen fertilization on the detection of nitrogen content in cotton (gossypium hirsutum l. var. latifolium hutch) leaves using reflectance properties registered by an active optical sensor. the experiment was conducted in randomized blocks and treatments consisted of five levels of nitrogen (0, 50, 100, 150 and 200 kg of n ha-1) with four replications. normalized difference vegetation index (ndvi) and the ratio red/near infrared (red/nir) data were collected 23 to 92 days after the emergence (dae), with the total of 9 dates. data referring to the chlorophyll index, leaf area index (lai) and plant height were also collected. the values of ndvi presented a tendency to increase along the period, while red/nir presented an inverse trend, being significantly affected by the rates of applied n starting from 45 dae. at 92 dae, ndvi presented a positive linear relationship with n contents of leaves. significant relationships were observed between the values of ndvi and chlorophyll index and lai. the sensor may be a potential tool for nitrogen deficiency detection in cotton.
Diagnose nutricional com o uso de sensor óptico ativo em algodoeiro Nutritional diagnosis with the use of active optical sensor in cotton
Anamari V. de A. Motomiya,José P. Molin,Wagner R. Motomiya,Guilherme A. Biscaro
Revista Brasileira de Engenharia Agrícola e Ambiental , 2012, DOI: 10.1590/s1415-43662012001100003
Abstract: Este trabalho objetivou avaliar a resposta espectral do dossel de plantas à varia o de doses de nitrogênio (N) e sua rela o com os teores foliares de N, índice de clorofila e produtividade na cultura do algodoeiro. O experimento foi conduzido em Chapad o do Sul, MS, no delineamento em blocos casualizados, com quatro repeti es. Os tratamentos consistiram de cinco doses de N: 0, 30, 70, 110 e 150 kg ha-1, divididas em duas aplica es aos 28 e 41 dias após a emergência utilizando-se, como fonte, o fertilizante ureia. As maiores correla es dos índices de clorofila e do índice de vegeta o por diferen a normalizada com a produtividade foram observadas na quarta leitura, aos 56 dias após a emergência, indicando que neste período a produtividade já pode estar comprometida caso haja falhas no suprimento de N à cultura. Os resultados obtidos indicaram que o sensor se torna mais sensível à varia o do teor foliar de N conforme a planta se desenvolve mas n o quando ela atinge um alto índice de área foliar e come a a entrar em senescência. Concluiu-se, ent o, que o sensoriamento remoto ao nível terrestre permite estimar indiretamente a quantidade de N absorvido, o índice de clorofila e a produtividade do algodoeiro. This research aimed to evaluate the spectral response to variation of nitrogen levels and its relationship with leaf nitrogen, chlorophyll and yield in cotton crop. The experiment was conducted in Chapad o do Céu, MS, in a randomized block design with four replications. The treatments consisted of five N rates of 0, 30, 70, 110 and 150 kg ha-1, divided in two applications at 28 and 41 days after emergence, using urea fertilizer as a source. The highest correlations of the chlorophyll index and normalized difference vegetation index with yield were observed in the fourth observation, at 56 days after emergence, indicating that in this period, yield may already be compromised if there is shortage in the supply of N to the crop. The results obtained indicated that the sensor becomes more sensitive to variations of nitrogen levels as the crop grows, but not when it reaches a high leaf area index and in the begining of the senescence. It is concluded that ground level remote sensing permits to estimate indirectly the amount of N absorbed, chlorophyll index and cotton yield.
Uso da krigagem indicatriz na avalia??o de indicadores de fertilidade do solo
Motomiya, Anamari Viegas de Araújo;Corá, José Eduardo;Pereira, Gener Tadeu;
Revista Brasileira de Ciência do Solo , 2006, DOI: 10.1590/S0100-06832006000300010
Abstract: the objective of this study was to identify site-specific management zones by means of chemical soil fertility indicators on sugarcane-cultivated latosols (oxisols), using indicator kriging, aiming an optimized use of precision agriculture techniques. the study was conducted in a 90 ha section of a larger field (1.900 ha) near jaboticabal, s?o paulo state - brazil (21 ° 15 ' s and 48 ° 18 ' w). a 50 m regular grid was drawn on the experimental area (300 by 3.000 m). soil samples were obtained at each 50 m grid point (420 points) from the top 0.2 m. organic matter, p, k and v values of the soil samples were determined. the soil data were coded as 0 or 1 when higher or lower than the threshold value established for each variable, respectively. using the results of geostatistical analysis for the coded data set and indicator kriging, counter maps of probability of meeting the critical threshold value for each of the individual soil attributes and their combinations were drawn. it was possible to identify areas of different soil fertility levels by this method.
Impacto energético da irriga??o por gotejamento no cultivo de mamona
Jordan, Rodrigo Aparecido;Gomes, Eder Pereira;Biscaro, Guilherme Augusto;Motomiya, Anamari Viegas de Araújo;Geisenhoff, Luciano;
Pesquisa Agropecuária Tropical , 2012, DOI: 10.1590/S1983-40632012000400005
Abstract: irrigation is a technique with high potential to increase crop yield, however, it is necessary to evaluate the energetic efficiency of irrigated agriculture. so, this study aimed at evaluating the irrigation impact on grain yield and energetic balance of two castor bean cultivars submitted to supplementary drip irrigation with different water depths. the experiment was conducted in a clayey dystrophic purple latosol, in dourados, mato grosso do sul state, brazil. the experimental design was randomized blocks in a bifactorial scheme, with five water depths (0%, 25%, 50%, 100% and 150% of evapotranspiration for localized irrigation) and two castor bean cultivars (iac 2028 and iac 80), with four replications. the irrigation interval was of up to two irrigations per week, except for the days when rainfall occurred. crop yield and the relation energy produced in the form of grains/energy used in cultivation were evaluated. it was concluded that the supplementary irrigation increased yield, as well as the relationship between energy production and consumption.
Molibdênio via semente e nitrogênio em cobertura no feijoeiro irrigado em solo de cerrado
Biscaro, Guilherme Augusto;Goulart Junior, Sidney Antonio Roseiro;Soratto, Rogério Peres;Freitas Júnior, Nasir Augusto de;Motomiya, Anamari Viegas de Araújo;Calado Filho, Gilmar Cordeiro;
Ciência e Agrotecnologia , 2009, DOI: 10.1590/S1413-70542009000500012
Abstract: nitrogen is the most required nutrient by common bean and its metabolism depends on the molybdenum supply. the objective of this work was to evaluate the effect of the molybdenum applied to seeds as well as the effect of sidedressing nitrogen on agronomic characteristics of irrigated common bean, cultivar brs pontal, grown on typic quartzipsamment, in cassilancia county, mato grosso do sul state, brazil. a randomized complete block design was used, in a 4x2 factorial array with four replications. the treatments were constituted of absence or presence of mo (80g ha-1) applied to seeds, and four n doses (0, 30, 60, and 120 kg ha-1) applied 16 days after emergence, as urea. molybdenum applied to seeds increased the relative chlorophyll index, number of pods per plant, mass of grains, and grain yield, mainly with high n-sidedressing rates. the n-sidedressing application up to the highest dose (120 kg ha-1) promoted a linear increase in the relative chlorophyll index, number of pods per plant, mass of grains and grain yield. molybdenum applied to seeds increased the efficiency of n use by common bean.
Necessary conditions for the existence of 3-designs over finite fields with nontrivial automorphism groups
Maarten De Boeck,Anamari Nakic
Mathematics , 2015,
Abstract: A q-design with parameters t-(v,k,lambda_t)_q is a pair (V, B) of the v-dimensional vector space V over GF(q) and a collection B of k-dimensional subspaces of V, such that each t-dimensional subspace of V is contained in precisely lambda_t members of B. In this paper we give new general necessary conditions on the existence of designs over finite fields with parameters 3-(v, k , lambda_3)_q with a prescribed automorphism group. These necessary conditions are based on a tactical decomposition of such a design over a finite field and are given in the form of equations for the coefficients of tactical decomposition matrices. In particular, they represent necessary conditions on the existence of q-analogues of Steiner systems admitting a prescribed automorphism group.
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