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Search Results: 1 - 10 of 7332 matches for " Amauri Nelson;Centurion "
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Resistência à penetra??o em latossolos: valor limitante à produtividade de arroz de sequeiro
Beutler, Amauri Nelson;Centurion, José Frederico;
Ciência Rural , 2004, DOI: 10.1590/S0103-84782004000600019
Abstract: the objetive of this work was to evaluate the value of resistance to penetration limit to dry land rice yield (oryza sativa cv. iac 165) grown in soil with water content at tension of 0.05 and 0.01mpa. soil was sampled at 0.00-0.20m depth in haplustox, medium texture (lvd) and eutrustox, clayey (lvef) and compacted in layers of 0.03m in pots of 0.20m height and 0.25m diameter (0.00982m3). the values of resistance to penetration were measured by dinamometric ring penetrometer. the experiment was complete randomized, in a 4 x 2 factorial, with 3 replications. for the water content at tension of 0.01mpa, the value of resistance to penetration limit to dry land rice yield was 2.38 and 2.07mpa, respectively, for lvd and lvef. higher rice yield was obtained in smaller value of resistance to penetration in water content at tension of 0.05mpa. the dry land rice was less productive in soil with water content at tension of 0.05mpa.
Compacta??o do solo no desenvolvimento radicular e na produtividade da soja
Beulter, Amauri Nelson;Centurion, José Frederico;
Pesquisa Agropecuária Brasileira , 2004, DOI: 10.1590/S0100-204X2004000600010
Abstract: in compacted soils, changes in the distribution of plant root system occur in depth. the objective of this study was to evaluate the compaction effect in soybean root development and yield in an oxisol. the treatments were 0, 1, 2, 4 and 6 passed of a 11 mg tractor, side, by side, on soil surface. the experimental design was a completely randomized, with four replications. in december, 2002, soybean (glycine max cv. embrapa 48) was sown, and after that, the samples were collected in layers of 0.02-0.05, 0.07-0.10 and 0.15-0.18 m, for physical determinations. in r6 stadium, samples of 0.10 m in line x 0.20 m between lines, in layers of 0.0-0.05, 0.05-0.10, 0.10-0.15 and 0.15-0.20 m were collected. soybean yield was evaluated in plots of 3.6 m2. the increase in compaction increased the root density and the root dry matter in layer of 0.0-0.05 m and caused linear decrease in the most compacted layers of 0.05-0.10 and 0.10-0.15 m. from the decrease of 18% of root density, in resistance to penetration of 0.85 mpa, in the depth of 0.05-0.15 m, there was reduction in soybean yield. soil compaction promoted modifications in the distribution of the soybean root system.
Efeito do conteúdo de água e da compacta??o do solo na produ??o de soja
Beutler, Amauri Nelson;Centurion, José Frederico;
Pesquisa Agropecuária Brasileira , 2003, DOI: 10.1590/S0100-204X2003000700009
Abstract: soil compaction has been limiting physical factor to plants growth. this work aimed to evaluate the production of soybean (glycine max cv. embrapa 48) as affected by water content and soil compaction. the experimental design was completely randomized, in a factorial scheme 4x2, i.e., four levels of resistance to penetration (between 0.27 and 4.32 mpa) and two levels of soil water retention (0.05 and 0.01 mpa). samples of red latossol medium texture and red latossol clayey were collected in 020 cm depth, sieved in mesh of 0.4 cm and compacted in layers of 3 cm in pots of 20 cm height and 25 cm of diameter (9.82 l). the levels of resistance to penetration were determined with dynamometric ring penetrometer. the critical level of soil resistance to penetration, in relation to grains production, was 1.66 and 2.22 mpa, in red latossol medium texture, and 3.05 and 2.81 mpa, in red latossol clayey, for the water content in tension of 0.05 and 0.01 mpa, respectively. the higher grains production was obtained in tension of 0.01 mpa. soybean production is affected by levels of soil resistance to penetration superior to 2 mpa in latossols under tension of 0.01 mpa.
Soil compaction and fertilization in soybean productivity
Beutler, Amauri Nelson;Centurion, José Frederico;
Scientia Agricola , 2004, DOI: 10.1590/S0103-90162004000600010
Abstract: soil compaction and fertilization affect soybean development. this study evaluated the effects of soil compaction and fertilization on soybean (glycine max cv. embrapa 48) productivity in a typic haplustox under field conditions in jaboticabal, sp, brazil. a completely randomized design with a 5 x 2 factorial layout (compaction vs. fertilization), with four replications in each treatment, was employed. each experimental unit (replicate) consisted of a 3.6 m2 useful area. after the soil was prepared by cultivation, an 11 mg tractor passed over it a variable number of times to create five levels of compaction. treatments were: t0= no compaction, t1= one tractor pass, t2= two, t4= four, and t6= six passes, and no fertilizer and fertilizer to give soybean yields of 2.5 to 2.9 mg ha-1. soil was sampled at depths of 0.02-0.05, 0.07-0.10, and 0.15-0.18 m to determine macro and microporosity, penetration resistance (pr), and bulk density (db). after 120 days growing under these conditions, the plants were analyzed in terms of development (plant height, number of pods, shoot dry matter per plant and weight of 100 seeds) and seed productivity per hectare. soil compaction decreased soybean development and productivity, but this effect was decreased by soil fertilization, showing that such fertilization increased soybean tolerance to soil compaction.
Efeito do conteúdo de água e da compacta o do solo na produ o de soja
Beutler Amauri Nelson,Centurion José Frederico
Pesquisa Agropecuária Brasileira , 2003,
Abstract: A compacta o do solo tem sido fator físico limitante ao crescimento das plantas. Este trabalho objetivou avaliar a produ o de soja (Glycine max cv. EMBRAPA 48) em raz o do conteúdo de água e da compacta o do solo. Usou-se o delineamento inteiramente casualizado, em esquema fatorial 4x2, ou seja, quatro níveis de resistência à penetra o (entre 0,27 e 4,32 MPa) e dois níveis de reten o de água pelo solo (0,05 e 0,01 MPa). Foram utilizadas amostras de Latossolo Vermelho textura média (LVd) e Latossolo Vermelho textura argilosa (LVef), coletadas na profundidade de 020 cm, passadas em peneira de 0,4 cm e compactadas em camadas de 3 cm, em vasos de 20 cm de altura e 25 cm de diametro (9,82 L). Os níveis de resistência à penetra o foram determinados com o penetr metro de anel dinamométrico. O nível crítico de resistência do solo à penetra o, em rela o à produ o de gr os, foi de 1,66 e 2,22 MPa, no LVd, e 3,05 e 2,81 MPa, no LVef, para o conteúdo de água retida na tens o de 0,05 e 0,01 MPa, respectivamente. A maior produ o de gr os foi obtida na tens o de 0,01 MPa. A produ o de gr os de soja é afetada em níveis críticos de resistência do solo à penetra o superiores a 2 MPa em latossolos com conteúdo de água retida na tens o de 0,01 MPa.
Soil compaction and fertilization in soybean productivity
Beutler Amauri Nelson,Centurion José Frederico
Scientia Agricola , 2004,
Abstract: Soil compaction and fertilization affect soybean development. This study evaluated the effects of soil compaction and fertilization on soybean (Glycine max cv. Embrapa 48) productivity in a Typic Haplustox under field conditions in Jaboticabal, SP, Brazil. A completely randomized design with a 5 x 2 factorial layout (compaction vs. fertilization), with four replications in each treatment, was employed. Each experimental unit (replicate) consisted of a 3.6 m2 useful area. After the soil was prepared by cultivation, an 11 Mg tractor passed over it a variable number of times to create five levels of compaction. Treatments were: T0= no compaction, T1= one tractor pass, T2= two, T4= four, and T6= six passes, and no fertilizer and fertilizer to give soybean yields of 2.5 to 2.9 Mg ha-1. Soil was sampled at depths of 0.02-0.05, 0.07-0.10, and 0.15-0.18 m to determine macro and microporosity, penetration resistance (PR), and bulk density (Db). After 120 days growing under these conditions, the plants were analyzed in terms of development (plant height, number of pods, shoot dry matter per plant and weight of 100 seeds) and seed productivity per hectare. Soil compaction decreased soybean development and productivity, but this effect was decreased by soil fertilization, showing that such fertilization increased soybean tolerance to soil compaction.
Resistência à penetra o em latossolos: valor limitante à produtividade de arroz de sequeiro
Beutler Amauri Nelson,Centurion José Frederico
Ciência Rural , 2004,
Abstract: Este trabalho objetivou avaliar o valor de resistência à penetra o limitante à produtividade de arroz de sequeiro (Oryza sativa cv. IAC 165) no conteúdo de água retida, na tens o de 0,05 e 0,01 MPa. Foram utilizadas amostras de Latossolo Vermelho, textura média (LVd) e, Latossolo Vermelho, textura argilosa (LVef), coletadas na profundidade de 0,00-0,20m, passadas em peneira de 0,004m e compactados em camadas de 0,03m, em vasos de 0,20m de altura e 0,25m de diametro (0,00982m3). Os valores de resistência à penetra o foram determinados com o penetr metro de anel dinamométrico. Utilizou-se o delineamento inteiramente casualizado, em esquema fatorial 4 x 2, com três repeti es. No conteúdo de água retida, na tens o de 0,01MPa, o valor de resistência do solo à penetra o limitante à produtividade de gr os de arroz de sequeiro foi de 2,38 e 2,07MPa, respectivamente, para o LVd e LVef. No conteúdo de água retida na tens o de 0,05MPa foram obtidas maiores produ es no menor valor de resistência à penetra o. O arroz de sequeiro foi menos produtivo no conteúdo de água retida na tens o de 0,05MPa.
Physical attributes of kaolinitic and oxidic oxisols resulting from different usage systems
Centurion, José Frederico;Beutler, Amauri Nelson;Souza, Zigomar Menezes de;
Brazilian Archives of Biology and Technology , 2004, DOI: 10.1590/S1516-89132004000500007
Abstract: the objective of this study was to assess the physical attributes of a kaolinitic oxisol, medium texture (haplustox) and an oxidic oxisol, clayey (eutrustox) under different usage systems, localized in the region of jaboticabal, sp, brazil. the usage systems were sugarcane, cotton and forest. parameters such as soil bulk density, total porosity, macro and microporosity at the depths of 0.0-0.1; 0.1-0.2; 0.2-0.3, and 0.3-0.4 m were evaluated. haplustox showed greater bulk density and smaller total porosity, macro and microporosity. the usage increased the bulk density in 0.0-0.3 m depth, with greater effects on the kaolinitic oxisol, mainly in 0.1-0.2 m depth in the areas cultivated with sugarcane.
Soil resistance to penetration and least limiting water range for soybean yield in a haplustox from Brazil
Beutler, Amauri Nelson;Centurion, José Frederico;Silva, Alvaro Pires da;
Brazilian Archives of Biology and Technology , 2005, DOI: 10.1590/S1516-89132005000800002
Abstract: the objective of this study was determine the resistance to penetration (pr), least limiting water range (llwr) and critical bulk density (db-crit) for soybean yield in a medium-textured oxisol (haplustox). the treatments represented the soil compaction by passing a tractor over the site 0, 1, 2, 4, and 6 times, with 4 replications in a randomized experimental design. samples were collected from 0.02-0.05, 0.07-0.10 and 0.15-0.18 m depths. soybean (glycine max cv. embrapa 48) was sowed in december 2002. plant height, number of pods, aerial dry matter, weight of 100 seeds, and the yield in 3.6 m2 plots were recorded. soybean yield started reduction at the pr of 0.85 mpa and db of 1.48 mg m-3. the llwr was limited in highest part by water content at field capacity (0.01 mpa tension) and in lowest part by water content at prcrit, achieved the db-crit to yield at 1.48 mg m-3.
Rela??o entre alguns atributos físicos e a produ??o de gr?os de soja e arroz de sequeiro em latossolos
Beutler, Amauri Nelson;Centurion, José Frederico;Roque, Cassiano Garcia;
Ciência Rural , 2004, DOI: 10.1590/S0103-84782004000200005
Abstract: this work aimed to evaluate some physical attributes and their correlation with production of soybean (glycine max) and rice (oryza sativa) in three levels of soil compaction and two water contents (tension of 0.01 and 0.05mpa), with three replications. samples of a haplustox and a eutrustox were collected at 0-20cm depth and compacted in layers of 3cm in pots of 9.82l. the total porosity, macro and microporosity, bulk density, penetration resistance and soybean and rice grain production were evaluated. the physical attributes presented high and significant correlations among them for all soils na water contents. the greater correlations of physical attributes with soybean and rice grain production were obtained in haplustox at water content at 0.05mpa, condition where greater reduction of grains production with increase of compaction occurred. the correlations of macroporosity and total porosity with grain production of both crops were positive, while microporosity, bulk density and penetration resistance correlations were negative.
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