The drained residual shear strength at the interface between soils and solid materials can be of importance in evaluating the stability of geotechnical structures. Drained residual shear tests have been performed at relatively high effective normal stress levels, over 50 kPa. These effective normal stresses are relevant for many field applications and manageable in typical laboratory shear testing. However, there are field applications, such as offshore pipelines where the effective normal stresses can be below 50 kPa. There are two significant challenges in measuring the drained shear strength at low effective normal stresses: (1) a small amount of friction in a test device can affect the results; (2) small shear rates may be required to achieve drained conditions at the soils. A tilt table test method has been developed to overcome these challenges. The objective of this work is to measure the drained residual shear and interface strength of soils at low effective normal stresses so as to provide logical explanations of the effect of various parameters. These parameters include soil index properties, clay content, clay mineralogy, stress history, and loading rate together with the effective normal stress levels. The total 74 tilt table tests are performed to measure the drained residual shear and interface strength of marine clays and sand-kaolinite mixtures. The following conclusions can be drawn based on the test results. 1. The drained residual shear strength both for the interface and for the soils is not affected by the over-consolidation ratio. 2. The drained residual shear strengths for the interfaces are all less than the drained residual shear strengths of soils. The drained residual strength of interface depends on the roughness of interface, clay mineralogy. 3. The empirical correlations and shear test results at higher effective normal stresses cannot be extrapolated to lower effective normal stresses. 4. Clay mineralogy and clay contents together with the magnitude of effective normal stress are the most important factors to estimate the drained residual shear strength of cohesive soils. 5. Cohesionless soils exhibit a constant residual secant friction angle regardless of effective normal stress levels. / text

The aim of this study was to determine growth responses and apparent total tract nutrient digestibility in growing pigs fed diets containing graded levels of distillers dried grains with solubles (DDGS) and to determine the effect of a multicarbohydrase enzyme (MC) supplementation on visceral organ mass and fasting whole-body oxygen consumption (FWBOC). In Experiment 1, 48 pigs (25.5 ± 0.14 kg BW) were assigned on the basis of sex and BW (2 pigs per pen) to 4 diets (6 pens per diet) based on corn-barley-soybean meal with 0, 10, 20 and 30% DDGS in a 42-d trial. Apparent total tract digestibilities (ATTD) of energy and other nutrients were determined using acid insoluble ash (AIA) as the indigestible marker. Inclusion of DDGS in the diets decreased (linear, P < 0.05) average daily gain (ADG) and tended to decrease gain to feed ratio (G:F) (linear, P = 0.067) but not average daily feed intake (ADFI) (P > 0.10); however, pigs fed the 20% DDGS diet had similar ADG as pigs fed the 0% DDGS diet. Increasing DDGS content in the diet linearly decreased (P < 0.01) the ATTD of DM, energy and CP (cubic, P < 0.05) but not (P > 0.10) P and Ca; however, ATTD of neutral detergent fiber (NDF) increased (linear, P < 0.01) when DDGS was included in the diet. In Experiment 2, 24 pigs (19.9 ± 0.46 kg BW) were randomly assigned to 3 corn-soybean meal-basal diets (8 pigs per diet): Control (C, 0% DDGS); basal diet with 30% DDGS (C+30% DDGS) or C+30% DDGS supplemented with MC (C+30% DDGS+MC). On d 15, WBOC during the 24- to 30-h postprandial period was determined using an open-circuit indirect calorimeter on 4 pigs per diet. On d 28, pigs were killed to determine visceral organ mass and intestinal morphology. There was no diet effect (P > 0.10) on final BW, FWBOC, and liver, spleen, pancreas, heart, stomach and caecum weights relative to empty BW. However, pigs fed the C and C+30% DDGS+MC had heavier (P = 0.05) empty BW compared with those fed unsupplemented 30% DDGS-containing diet. Small intestine, colon plus rectum and the portal-drained viscera (PDV) were heavier (P < 0.05) in DDGS-fed pigs compared with C; supplementing with MC substantially decreased the effect of DDGS on the weight of these visceral organs. Feeding pigs DDGS tended to decrease (P < 0.10) villous height (VH) and VH:CD in the ileum. Results show that including DDGS in grower pig diets up to 20% has no effect on performance although ATTD of energy, DM, and N may be reduced. Inclusion of DDGS at 30% increased PDV mass and reduced dressing percentage but these effects were overcome by a multicarbohydrase enzyme supplementation.

The aim of this study was to determine growth responses and apparent total tract nutrient digestibility in growing pigs fed diets containing graded levels of distillers dried grains with solubles (DDGS) and to determine the effect of a multicarbohydrase enzyme (MC) supplementation on visceral organ mass and fasting whole-body oxygen consumption (FWBOC). In Experiment 1, 48 pigs (25.5 ± 0.14 kg BW) were assigned on the basis of sex and BW (2 pigs per pen) to 4 diets (6 pens per diet) based on corn-barley-soybean meal with 0, 10, 20 and 30% DDGS in a 42-d trial. Apparent total tract digestibilities (ATTD) of energy and other nutrients were determined using acid insoluble ash (AIA) as the indigestible marker. Inclusion of DDGS in the diets decreased (linear, P < 0.05) average daily gain (ADG) and tended to decrease gain to feed ratio (G:F) (linear, P = 0.067) but not average daily feed intake (ADFI) (P > 0.10); however, pigs fed the 20% DDGS diet had similar ADG as pigs fed the 0% DDGS diet. Increasing DDGS content in the diet linearly decreased (P < 0.01) the ATTD of DM, energy and CP (cubic, P < 0.05) but not (P > 0.10) P and Ca; however, ATTD of neutral detergent fiber (NDF) increased (linear, P < 0.01) when DDGS was included in the diet. In Experiment 2, 24 pigs (19.9 ± 0.46 kg BW) were randomly assigned to 3 corn-soybean meal-basal diets (8 pigs per diet): Control (C, 0% DDGS); basal diet with 30% DDGS (C+30% DDGS) or C+30% DDGS supplemented with MC (C+30% DDGS+MC). On d 15, WBOC during the 24- to 30-h postprandial period was determined using an open-circuit indirect calorimeter on 4 pigs per diet. On d 28, pigs were killed to determine visceral organ mass and intestinal morphology. There was no diet effect (P > 0.10) on final BW, FWBOC, and liver, spleen, pancreas, heart, stomach and caecum weights relative to empty BW. However, pigs fed the C and C+30% DDGS+MC had heavier (P = 0.05) empty BW compared with those fed unsupplemented 30% DDGS-containing diet. Small intestine, colon plus rectum and the portal-drained viscera (PDV) were heavier (P < 0.05) in DDGS-fed pigs compared with C; supplementing with MC substantially decreased the effect of DDGS on the weight of these visceral organs. Feeding pigs DDGS tended to decrease (P < 0.10) villous height (VH) and VH:CD in the ileum. Results show that including DDGS in grower pig diets up to 20% has no effect on performance although ATTD of energy, DM, and N may be reduced. Inclusion of DDGS at 30% increased PDV mass and reduced dressing percentage but these effects were overcome by a multicarbohydrase enzyme supplementation.

No description available.

Over the last millennium peatlands have accumulated significant carbon stores. Drainage for agricultural use has been widespread and has altered the functioning of these mires: shifting them towards carbon release. Recently, in recognition of the range of ecosystem services derived from these landscapes peatland restoration projects have been initiated. Carbon storage is often cited amongst the aims of these projects, especially since the inclusion of rewetting wetlands in the Kyoto Protocol. However, little is known about the effects of ditch blocking on CO2 fluxes, particularly in Molinia caerulea dominated peatlands, a species common on degraded peatlands which tolerates a range of water table depths. This thesis aims firstly to quantify CO2 fluxes from a drained Molinia caerulea dominated blanket bog and to improve understanding of the temporal and spatial controls on these fluxes and secondly, to quantify the immediate effects of ditch blocking. Closed chamber measurements of net ecosystem exchange and partitioned below-ground respiration from control-restored paired sites were collected over the growing seasons immediately pre- (2012) and post-restoration (2013/2014). These flux data were coupled with remotely sensed data quantifying vegetation phenology and structure with a fine resolution (daily/cm) over large extents (annual/catchment). Although temporal variation in water table depth was not related to CO2 fluxes, the seasonal average related to vegetation composition suggesting raising water tables may promote a change in vegetation composition within these species-poor ecosystems. The distribution of water table depths, vegetation composition and CO2 fluxes did not vary with proximity to drainage ditches despite their prominence. An empirical model suggests in a drained state these peatlands are CO2 sources, indicating carbon previously accumulated is gradually being lost. Data suggest restoration does not always significantly affect water tables and consequently CO2 fluxes in the short-term. Where shallower water tables were maintained during dry conditions photosynthesis decreased and heterotrophic respiration increased: enhancing carbon release. Research undertaken during atypical weather has been unable to determine if restoration will be able to raise water tables sufficiently to protect the existing peat store and promote the vegetation change required to reinstate CO2 sequestration in the longer-term.

Entre os objetivos da engenharia geotécnica está a busca pelo entendimento e previsão do comportamento mecânico dos solos. Para isso, existem basicamente duas abordagens: ensaios de laboratório ou ensaios de campo. Em cada obra o Engenheiro Geotécnico deve julgar quais são os métodos e procedimentos mais indicados de investigação, que resultarão em parâmetros confiáveis de projeto. Os ensaios de campo foram desenvolvidos baseados nos solos argilosos e arenosos em virtude dos comportamentos distintamente bem definidos, especialmente em termos de drenagem. O mesmo ocorre para o ensaio DMT, cuja execução e interpretação são influenciadas pelo tipo de solo e pelas condições de drenagem. O grande desafio, neste caso, está na interpretação dos ensaios em solos cuja solicitação ocorre sob condição de drenagem parcial, como nos casos de barragens de rejeito de mineração, ou em depósitos naturais de solos siltosos, onde esta condição pode levar a erros de interpretação. No DMT, a ocorrência de drenagem parcial influencia tanto na etapa de cravação da lâmina, quanto na etapa de expansão da membrana. Neste sentido, o foco deste trabalho está no problema da dissipação de poropressão durante a expansão da membrana, apresentando procedimentos especiais para realização do ensaio DMT. Serão apresentados dois métodos de interpretação de resultados, visando compensar os erros de interpretação causados pela dissipação parcial de poropressão: Método de Dissipação Completa e, Método de Dissipação Incompleta. Este trabalho foi desenvolvido baseado na realização de ensaios de campo, com uma campanha executada em solo brasileiro argiloso, que serviu de base à interpretação, sendo complementada por 6 ensaios realizados em diferentes sítios na Itália. Os resultados dos ensaios realizados pelo Método de Dissipação Completa foram interpretados através de duas abordagens: Método da Igualdade (analítico) e Método Simplificado. Enquanto a interpretação do Método de Dissipação Incompleta é permitida apenas através de procedimento simplificado. A análise paramétrica apresentou comportamentos similares entre ambas abordagens, demonstrando que a taxa de dissipação é o fator que mais influencia nos resultados. Ao final, os métodos foram aplicados e validados em diferentes locais, apresentando resultados adequados e compatíveis com o comportamento previamente definido através de outros ensaios. / Among the geotechnical engineering goals are the understanding and prediction of soil behavior. For this, there are basically two approaches: laboratory or in situ tests. In this case, the Geotechnical Engineer must judge the most appropriate investigation methods and procedures that will result in reliable design parameters. In situ tests were developed for clay and sand given to the fact that the behavior of these soils is well-defined and drainage conditions are properly controlled. The DMT is no exception, with test and interpretation methods influenced by the drainage conditions. The challenge resides in the interpretation of tests carried out in soils under partial-drainage conditions, such as tailings dams or natural deposits of silty soils, where partial-drainage conditions are taking place around the DMT blade leading to errors on its interpretation. The partial drainage condition influences both the DMT blade penetration phase and the membrane expansion phase. In this sense, this work focus on the problem of the pore pressure dissipation taking place simultaneously to membrane expansion. A non-standard procedure is proposed to sounding the DMT in silts that include two methods for DMT interpretation in order to compensate the errors caused by the partial pore pressure dissipation: Method of Complete Dissipation Curve and Method of Incomplete Dissipation Curve. This work was developed based on tests carried out in Brazilian clay soils to develop the proposed approach that was validated latter in non-standard tests carried out in different Italian sites. The results of the tests performed by the complete dissipation method were interpreted through two approaches: Equality Method (analytical) and Simplified Method, while the interpretation of the incomplete dissipation method is possible only through simplified procedure. The parametric analysis showed that these approaches yield similar results, demonstrating that the dissipation rate is the most important factor in the analysis. At the end, the methods were applied and validated at different sites, showing results that are compatible to previously defined behavior of the soils.

Para a introdução da cultura do milho como alternativa de rotação de culturas em áreas cultivadas com arroz irrigado no Rio Grande do Sul, é necessário um sistema de irrigação e drenagem eficiente, sem ocasionar problemas de manejo para o cultivo do arroz. O objetivo deste trabalho é avaliar diferentes manejos de irrigação e drenagem visando introduzir o milho como alternativa técnica e econômica para rotação de cultura em Gleissolo Háplico Distrófico Típico, onde tradicionalmente se cultiva arroz. Foram avaliados alguns indicadores de rendimento do milho e a eficiência do uso da água (EUA) nas diferentes alternativas de manejos. Foram testados quatro tratamentos: (T1) microcamalhão de 15 cm de altura com irrigação por sulco sempre que necessário, (T2) uma testemunha com microcamalhão com 15 cm de altura sem irrigação, (T3) um sem construção de microcamalhão, com irrigação por banhos sempre que necessário, e (T4) outro sem construção de microcamalhão e sem irrigação. Todos os tratamentos foram realizados com três repetições. O experimento foi conduzido nos anos agrícolas 2013/2014 e 2014/2015, na estação experimental do IRGA em Cachoeirinha-RS. Em todos os tratamentos a área foi nivelada com uma declividade de 0,08%, ao longo do comprimento das parcelas (79 m). A lâmina irrigada foi de 30 mm e as irrigações foram efetuadas de maneira complementar à chuva por sulcos ou banhos. Os resultados desta pesquisa demonstram que a drenagem foi eficientenos dois anos, pois mesmo com ocorrência de eventos de chuva superiores a 50 mm em 24 horas, não houve problema de excesso hídrico. No primeiro ano foram aplicados 300 mm de irrigação (choveu 480 mm ao longo do desenvolvimento do milho) e os resultados indicam alta produtividade do milho (superiores a 10 Mg ha-1) para o tratamento irrigado e com microcamalhão. No segundo ano foram aplicados somente 90 mm de irrigação pois foi um ano muito úmido (choveu 620 mm durante o segundo ano agrícola). Em consequência disso, não houve diferença significativa nos resultados pois todas os tratamentos mantiveram-se na umidade ideal na maioria do tempo, apresentando altas produtividades de grãos (superiores a 13 Mg ha-1). O milho cultivado em áreas cultivadas com arroz irrigado no Rio Grande do Sul é tecnicamente e economicamente viável desde que ocorra o uso de irrigação e que se utilize um sistema de drenagem eficiente. / For the introduction of corn as crop rotation alternative in areas cultivated with rice in Rio Grande do Sul, efficient irrigation and drainage system is required, without causing management problems for rice cultivation. The objective of this study is to evaluate different management of irrigation and drainage aimed at introducing corn as technical and economical alternative to crop rotation in Gleissolo Háplico Distrófico Típico, where traditionally cultivated rice. We evaluated some corn performance indicators and efficiency of water use (EWU) in the different alternatives managements. Four treatments were tested: (T1) microcamalhão 15 cm with furrow irrigation whenever necessary, (T2) a witness with microcamalhão 15 cm without irrigation, (T3) without building microcamalhão, with irrigation when necessary, and (T4) without building microcamalhão and without irrigation. All treatments were performed with three replications. The experiment was conducted in the agricultural year 2013/2014 and 2014/2015, the IRGA's experimental station in Cachoeirinha-RS. In all treatments area was capped with a slope of 0.08% along the length of the parcels (79 m). Irrigated blade was 30 mm and irrigation was made in a complementary manner to rain by grooves or baths. These results demonstrate that the drainage was efficient in both years, since even the occurrence of rain events greater than 50 mm in 24 hours, there was no excess water problem. In the first year were applied 300 mm irrigation (480 mm rain during the development of corn) and the results indicate high corn yields (above 10 Mg ha-1) for the treatment irrigated and microcamalhão. In the second year there were only applied 90 mm of irrigation because it was a very wet year (620 mm rain during the second growing season) so there was no significant difference in the results for all treatments remained at the ideal humidity most of the time, high grain yield (above 13 Mg ha-1). The corn grown in areas cultivated with rice in Rio Grande do Sul is technically and economically feasible provided that there is an efficient irrigation and drainage system.

Para a introdução da cultura do milho como alternativa de rotação de culturas em áreas cultivadas com arroz irrigado no Rio Grande do Sul, é necessário um sistema de irrigação e drenagem eficiente, sem ocasionar problemas de manejo para o cultivo do arroz. O objetivo deste trabalho é avaliar diferentes manejos de irrigação e drenagem visando introduzir o milho como alternativa técnica e econômica para rotação de cultura em Gleissolo Háplico Distrófico Típico, onde tradicionalmente se cultiva arroz. Foram avaliados alguns indicadores de rendimento do milho e a eficiência do uso da água (EUA) nas diferentes alternativas de manejos. Foram testados quatro tratamentos: (T1) microcamalhão de 15 cm de altura com irrigação por sulco sempre que necessário, (T2) uma testemunha com microcamalhão com 15 cm de altura sem irrigação, (T3) um sem construção de microcamalhão, com irrigação por banhos sempre que necessário, e (T4) outro sem construção de microcamalhão e sem irrigação. Todos os tratamentos foram realizados com três repetições. O experimento foi conduzido nos anos agrícolas 2013/2014 e 2014/2015, na estação experimental do IRGA em Cachoeirinha-RS. Em todos os tratamentos a área foi nivelada com uma declividade de 0,08%, ao longo do comprimento das parcelas (79 m). A lâmina irrigada foi de 30 mm e as irrigações foram efetuadas de maneira complementar à chuva por sulcos ou banhos. Os resultados desta pesquisa demonstram que a drenagem foi eficientenos dois anos, pois mesmo com ocorrência de eventos de chuva superiores a 50 mm em 24 horas, não houve problema de excesso hídrico. No primeiro ano foram aplicados 300 mm de irrigação (choveu 480 mm ao longo do desenvolvimento do milho) e os resultados indicam alta produtividade do milho (superiores a 10 Mg ha-1) para o tratamento irrigado e com microcamalhão. No segundo ano foram aplicados somente 90 mm de irrigação pois foi um ano muito úmido (choveu 620 mm durante o segundo ano agrícola). Em consequência disso, não houve diferença significativa nos resultados pois todas os tratamentos mantiveram-se na umidade ideal na maioria do tempo, apresentando altas produtividades de grãos (superiores a 13 Mg ha-1). O milho cultivado em áreas cultivadas com arroz irrigado no Rio Grande do Sul é tecnicamente e economicamente viável desde que ocorra o uso de irrigação e que se utilize um sistema de drenagem eficiente. / For the introduction of corn as crop rotation alternative in areas cultivated with rice in Rio Grande do Sul, efficient irrigation and drainage system is required, without causing management problems for rice cultivation. The objective of this study is to evaluate different management of irrigation and drainage aimed at introducing corn as technical and economical alternative to crop rotation in Gleissolo Háplico Distrófico Típico, where traditionally cultivated rice. We evaluated some corn performance indicators and efficiency of water use (EWU) in the different alternatives managements. Four treatments were tested: (T1) microcamalhão 15 cm with furrow irrigation whenever necessary, (T2) a witness with microcamalhão 15 cm without irrigation, (T3) without building microcamalhão, with irrigation when necessary, and (T4) without building microcamalhão and without irrigation. All treatments were performed with three replications. The experiment was conducted in the agricultural year 2013/2014 and 2014/2015, the IRGA's experimental station in Cachoeirinha-RS. In all treatments area was capped with a slope of 0.08% along the length of the parcels (79 m). Irrigated blade was 30 mm and irrigation was made in a complementary manner to rain by grooves or baths. These results demonstrate that the drainage was efficient in both years, since even the occurrence of rain events greater than 50 mm in 24 hours, there was no excess water problem. In the first year were applied 300 mm irrigation (480 mm rain during the development of corn) and the results indicate high corn yields (above 10 Mg ha-1) for the treatment irrigated and microcamalhão. In the second year there were only applied 90 mm of irrigation because it was a very wet year (620 mm rain during the second growing season) so there was no significant difference in the results for all treatments remained at the ideal humidity most of the time, high grain yield (above 13 Mg ha-1). The corn grown in areas cultivated with rice in Rio Grande do Sul is technically and economically feasible provided that there is an efficient irrigation and drainage system.

Entre os objetivos da engenharia geotécnica está a busca pelo entendimento e previsão do comportamento mecânico dos solos. Para isso, existem basicamente duas abordagens: ensaios de laboratório ou ensaios de campo. Em cada obra o Engenheiro Geotécnico deve julgar quais são os métodos e procedimentos mais indicados de investigação, que resultarão em parâmetros confiáveis de projeto. Os ensaios de campo foram desenvolvidos baseados nos solos argilosos e arenosos em virtude dos comportamentos distintamente bem definidos, especialmente em termos de drenagem. O mesmo ocorre para o ensaio DMT, cuja execução e interpretação são influenciadas pelo tipo de solo e pelas condições de drenagem. O grande desafio, neste caso, está na interpretação dos ensaios em solos cuja solicitação ocorre sob condição de drenagem parcial, como nos casos de barragens de rejeito de mineração, ou em depósitos naturais de solos siltosos, onde esta condição pode levar a erros de interpretação. No DMT, a ocorrência de drenagem parcial influencia tanto na etapa de cravação da lâmina, quanto na etapa de expansão da membrana. Neste sentido, o foco deste trabalho está no problema da dissipação de poropressão durante a expansão da membrana, apresentando procedimentos especiais para realização do ensaio DMT. Serão apresentados dois métodos de interpretação de resultados, visando compensar os erros de interpretação causados pela dissipação parcial de poropressão: Método de Dissipação Completa e, Método de Dissipação Incompleta. Este trabalho foi desenvolvido baseado na realização de ensaios de campo, com uma campanha executada em solo brasileiro argiloso, que serviu de base à interpretação, sendo complementada por 6 ensaios realizados em diferentes sítios na Itália. Os resultados dos ensaios realizados pelo Método de Dissipação Completa foram interpretados através de duas abordagens: Método da Igualdade (analítico) e Método Simplificado. Enquanto a interpretação do Método de Dissipação Incompleta é permitida apenas através de procedimento simplificado. A análise paramétrica apresentou comportamentos similares entre ambas abordagens, demonstrando que a taxa de dissipação é o fator que mais influencia nos resultados. Ao final, os métodos foram aplicados e validados em diferentes locais, apresentando resultados adequados e compatíveis com o comportamento previamente definido através de outros ensaios. / Among the geotechnical engineering goals are the understanding and prediction of soil behavior. For this, there are basically two approaches: laboratory or in situ tests. In this case, the Geotechnical Engineer must judge the most appropriate investigation methods and procedures that will result in reliable design parameters. In situ tests were developed for clay and sand given to the fact that the behavior of these soils is well-defined and drainage conditions are properly controlled. The DMT is no exception, with test and interpretation methods influenced by the drainage conditions. The challenge resides in the interpretation of tests carried out in soils under partial-drainage conditions, such as tailings dams or natural deposits of silty soils, where partial-drainage conditions are taking place around the DMT blade leading to errors on its interpretation. The partial drainage condition influences both the DMT blade penetration phase and the membrane expansion phase. In this sense, this work focus on the problem of the pore pressure dissipation taking place simultaneously to membrane expansion. A non-standard procedure is proposed to sounding the DMT in silts that include two methods for DMT interpretation in order to compensate the errors caused by the partial pore pressure dissipation: Method of Complete Dissipation Curve and Method of Incomplete Dissipation Curve. This work was developed based on tests carried out in Brazilian clay soils to develop the proposed approach that was validated latter in non-standard tests carried out in different Italian sites. The results of the tests performed by the complete dissipation method were interpreted through two approaches: Equality Method (analytical) and Simplified Method, while the interpretation of the incomplete dissipation method is possible only through simplified procedure. The parametric analysis showed that these approaches yield similar results, demonstrating that the dissipation rate is the most important factor in the analysis. At the end, the methods were applied and validated at different sites, showing results that are compatible to previously defined behavior of the soils.

Para a introdução da cultura do milho como alternativa de rotação de culturas em áreas cultivadas com arroz irrigado no Rio Grande do Sul, é necessário um sistema de irrigação e drenagem eficiente, sem ocasionar problemas de manejo para o cultivo do arroz. O objetivo deste trabalho é avaliar diferentes manejos de irrigação e drenagem visando introduzir o milho como alternativa técnica e econômica para rotação de cultura em Gleissolo Háplico Distrófico Típico, onde tradicionalmente se cultiva arroz. Foram avaliados alguns indicadores de rendimento do milho e a eficiência do uso da água (EUA) nas diferentes alternativas de manejos. Foram testados quatro tratamentos: (T1) microcamalhão de 15 cm de altura com irrigação por sulco sempre que necessário, (T2) uma testemunha com microcamalhão com 15 cm de altura sem irrigação, (T3) um sem construção de microcamalhão, com irrigação por banhos sempre que necessário, e (T4) outro sem construção de microcamalhão e sem irrigação. Todos os tratamentos foram realizados com três repetições. O experimento foi conduzido nos anos agrícolas 2013/2014 e 2014/2015, na estação experimental do IRGA em Cachoeirinha-RS. Em todos os tratamentos a área foi nivelada com uma declividade de 0,08%, ao longo do comprimento das parcelas (79 m). A lâmina irrigada foi de 30 mm e as irrigações foram efetuadas de maneira complementar à chuva por sulcos ou banhos. Os resultados desta pesquisa demonstram que a drenagem foi eficientenos dois anos, pois mesmo com ocorrência de eventos de chuva superiores a 50 mm em 24 horas, não houve problema de excesso hídrico. No primeiro ano foram aplicados 300 mm de irrigação (choveu 480 mm ao longo do desenvolvimento do milho) e os resultados indicam alta produtividade do milho (superiores a 10 Mg ha-1) para o tratamento irrigado e com microcamalhão. No segundo ano foram aplicados somente 90 mm de irrigação pois foi um ano muito úmido (choveu 620 mm durante o segundo ano agrícola). Em consequência disso, não houve diferença significativa nos resultados pois todas os tratamentos mantiveram-se na umidade ideal na maioria do tempo, apresentando altas produtividades de grãos (superiores a 13 Mg ha-1). O milho cultivado em áreas cultivadas com arroz irrigado no Rio Grande do Sul é tecnicamente e economicamente viável desde que ocorra o uso de irrigação e que se utilize um sistema de drenagem eficiente. / For the introduction of corn as crop rotation alternative in areas cultivated with rice in Rio Grande do Sul, efficient irrigation and drainage system is required, without causing management problems for rice cultivation. The objective of this study is to evaluate different management of irrigation and drainage aimed at introducing corn as technical and economical alternative to crop rotation in Gleissolo Háplico Distrófico Típico, where traditionally cultivated rice. We evaluated some corn performance indicators and efficiency of water use (EWU) in the different alternatives managements. Four treatments were tested: (T1) microcamalhão 15 cm with furrow irrigation whenever necessary, (T2) a witness with microcamalhão 15 cm without irrigation, (T3) without building microcamalhão, with irrigation when necessary, and (T4) without building microcamalhão and without irrigation. All treatments were performed with three replications. The experiment was conducted in the agricultural year 2013/2014 and 2014/2015, the IRGA's experimental station in Cachoeirinha-RS. In all treatments area was capped with a slope of 0.08% along the length of the parcels (79 m). Irrigated blade was 30 mm and irrigation was made in a complementary manner to rain by grooves or baths. These results demonstrate that the drainage was efficient in both years, since even the occurrence of rain events greater than 50 mm in 24 hours, there was no excess water problem. In the first year were applied 300 mm irrigation (480 mm rain during the development of corn) and the results indicate high corn yields (above 10 Mg ha-1) for the treatment irrigated and microcamalhão. In the second year there were only applied 90 mm of irrigation because it was a very wet year (620 mm rain during the second growing season) so there was no significant difference in the results for all treatments remained at the ideal humidity most of the time, high grain yield (above 13 Mg ha-1). The corn grown in areas cultivated with rice in Rio Grande do Sul is technically and economically feasible provided that there is an efficient irrigation and drainage system.