Nutrient extraction and export by fully irrigated sugarcane varieties

A pesquisa tecnológica para suporte do setor sucroalcooleiro nacional mostra que são esporádicos os trabalhos desenvolvidos com cana-de-açúcar irrigada envolvendo a exigência nutricional. Nesse contexto, objetivou-se quantificar, durante o ciclo de cana-planta de 11 variedades de cana-de-açúcar (SP79-1011, RB813804, RB863129, RB872552, RB943365, RB72454, RB763710, SP78-4764, SP81-3250, RB867515 e RB92579) cultivadas sob irrigação plena, a capacidade de extração e exportação de N, P, K, Ca e Mg, bem como a exigência nutricional para produção de uma tonelada de colmo por hectare (TCH). A pesquisa foi realizada em campo, no município de Carpina, PE, durante a safra agrícola 2006/2007. O delineamento experimental empregado foi de blocos casualizados, com 11 tratamentos e quatro repetições. A extração e exportação de nutrientes, assim como a exigência nutricional, foram avaliadas aos 360 dias após o plantio (DAP) na parte aérea das plantas. A extração de nutrientes na parte aérea da cana-planta apresentou, em média, valores de 179, 25, 325, 226 e 87 kg ha-1 de N, P, K, Ca e Mg, respectivamente, o que proporcionou a seguinte ordem decrescente de extração: K > Ca > N > Mg > P. A exportação média de N, P, K, Ca e Mg pelo colmo das variedades irrigadas foi de 92; 15; 188; 187; e 66 kg ha-1; correspondendo, respectivamente, a 51, 60, 58, 83 e 76 % de todo o nutriente extraído na parte aérea da cana-planta, com destaque para as variedades RB92579 e SP81-3250 para o N, RB813804, RB863129, RB872552, RB763710, RB92579, SP78-4764, SP81-3250 e SP79-1011 para o P, SP79-1011, SP81-3250, RB813804, RB872552 e RB763710 para o K, RB92579 e RB863129 para o Ca e RB92579 para o Mg. Para produção de uma TCH, foram exigidos pelas variedades durante o ciclo de cana-planta valores médios de 0,91; 0,13; 1,71; 1,18; e 0,44 kg de N, P, K, Ca e Mg, respectivamente.A review of technology research supporting the Brazilian sugaralcohol sector shows that only sporadic studies with irrigated sugarcane have been developed to investigate nutritional requirements. In this context, the objective of this study was to quantify the capacity of extraction and export of N, P, K, Ca, and Mg as well as the nutritional requirement for the production of one ton of stalk per hectare (TCH) in the plant cane cycle of 11 sugarcane varieties (SP79-1011, RB813804, RB863129, RB872552, RB943365, RB72454, RB763710, SP78-4764, SP81-3250, RB867515, and RB92579) grown under full irrigation. The research was conducted under field conditions in the municipality of Carpina, PE, in the 2006/2007 growing season. The experiment was arranged in a randomized block design with 11 treatments and four replications. Nutrient extraction and export as well as nutritional requirements of the shoot components of the plants were evaluated 360 days after planting. The mean nutrient accumulation in shoots was 179, 25, 325, 226, and 87 kg ha-1 of N, P, K, Ca, and Mg, respectively.The average export of N, P, K, Ca, and Mg via stalks of the irrigated varieties was 92, 15, 188, 187, and 66 kg ha-1; corresponding, respectively, to 51, 60, 58, 83, and 76 % of the whole nutrient amount taken up by the cane plant. The extracted nutrient amounts were highest by the following varieties: RB92579 and SP81-3250 for N; RB813804, RB863129, RB872552, RB763710, RB92579 SP78-4764, SP81-3250 and SP79-1011 for P; SP79-1011, SP81-3250, RB813804, RB872552 and RB763710 for K; RB92579 and RB863129 for Ca; and RB92579 for Mg, for which the export values in stalks were highest. For the production of one TCH, the varieties needed 0.91, 0.13, 1.71, 1.18, and 0.44 kg of N, P, K, Ca, and Mg, respectively

RB962962, a sugarcane cultivar for late harvest

In the Northeast of Brazil, sugarcane cultivar RB962962 is harvested at the end of the cycle, between December and February, with a high sugar yield per area. Recommended for sandy soils of medium texture and fertility, it is resistant to the major diseases and fast-growing in plant and ratoon crops

Mixed modeling for fiber yield genetic selection in sugarcane

The current demand for clean and renewable energy has provoked considerable changes in the production system of agroindustrial companies. The generation of bioelectricity through the burning of sugarcane bagasse has considerably risen in the recent years. This work aimed to focus on the sugarcane genotypes selection for fiber productivity. The experiment was outlined in randomized blocks with four repetitions, and sixteen genotypes were evaluated. The evaluated traits  were: cane tons per hectare, sucrose tons per hectare, fiber tons per hectare, fiber content and apparent sucrose content. To the selection, the mixed linear models methodology was used. The heritability coefficients suggest a significant genetic gain and the harmonic means of relative performances of predicted genotypic values allowed the identification of stable genotypes related to the traits evaluated in four harvest cycles. Considering the current average demand of sugarcane agroindustry for varieties with fiber content between 12% and 17% and sucrose content near 13%, for energy generation and sugar production, the genotypes EECAC 06, EECAC 03, EECAC 04 and EECAC 07 are presented as commercial cultivation options. Highlights - Mixed models constitute an efficient tool for sugarcane selection focused onto fiber and sucrose production. - This methodology provides significant genetic gains based on predicted genetic values free from interaction with harvest cycles. - The evaluated genotypes present high fiber and sucrose productivity, genotypic adaptability and stability throughout harvest cycles, indicating longevity in the sugarcane crop.The current demand for clean and renewable energy has provoked considerable changes in the production system of agroindustrial companies. The generation of bioelectricity through the burning of sugarcane bagasse has considerably risen in the recent years. This work aimed to focus on the sugarcane genotypes selection for fiber productivity. The experiment was outlined in randomized blocks with four repetitions, and sixteen genotypes were evaluated. The evaluated traits  were: cane tons per hectare, sucrose tons per hectare, fiber tons per hectare, fiber content and apparent sucrose content. To the selection, the mixed linear models methodology was used. The heritability coefficients suggest a significant genetic gain and the harmonic means of relative performances of predicted genotypic values allowed the identification of stable genotypes related to the traits evaluated in four harvest cycles. Considering the current average demand of sugarcane agroindustry for varieties with fiber content between 12% and 17% and sucrose content near 13%, for energy generation and sugar production, the genotypes EECAC 06, EECAC 03, EECAC 04 and EECAC 07 are presented as commercial cultivation options. Highlights - Mixed models constitute an efficient tool for sugarcane selection focused onto fiber and sucrose production. - This methodology provides significant genetic gains based on predicted genetic values free from interaction with harvest cycles. - The evaluated genotypes present high fiber and sucrose productivity, genotypic adaptability and stability throughout harvest cycles, indicating longevity in the sugarcane crop

Productivity, water use efficiency, and technological quality of sugarcane subjected to differents water regimes

O objetivo deste trabalho foi avaliar a produtividade de colmos e de açúcar, a eficiência de uso da água e os atributos tecnológicos de cinco variedades de cana-de-açúcar de maturação precoce e seis de maturação média à tardia, submetidas ao regime de sequeiro (1.141,4 mm) e à irrigação plena (1.396,6 mm). Utilizou-se o delineamento experimental de blocos ao acaso, com quatro repetições. A produtividade de colmos das variedades RB92579, RB72454 e SP81-3250 apresentou ganhos superiores a 180%, com uso da irrigação. A irrigação promoveu aumentos na produtividade de açúcar superiores a 200%, nas variedades RB92579 e RB943365. A irrigação plena proporcionou maior eficiência de uso da água, com produção média de 70,2 kg ha-1 mm-1 de colmos a mais em comparação ao regime de sequeiro. Com exceção das variedades RB72454, RB763710 e RB943365, não houve diferença nos atributos tecnológicos entre a irrigação plena e o regime de sequeiro. As variedades RB92579 e SP81-3250 de maturação média à tardia se destacam quanto à produtividade de colmos e de açúcar e à eficiência de uso da água, e são recomendadas para estudos de resposta à irrigação pela cana-de-açúcar.The  objective  of  this  work  was  to  assess stalk  and sugar  yield,  water  use  efficiency,  and technological attributes of five early maturing and six medium to late maturing sugarcane varieties with no irrigation (1,141.4 mm) and under full irrigation (1,396.6 mm). A randomized complete block design, with four replicates, was used. Stalk yield for varieties RB92579, RB72454, and SP81-3250 showed gains above 180% with irrigation. Irrigation increased sugar yield in more than 200% in the RB92579 and RB943365 varieties. Full irrigation provided greater water use efficiency, producing, in average, 70.2 kg ha-1 mm-1 more stalks than under no irrigation. Except for the varieties RB72454, RB763710, and RB943365, there were no differences regarding technological attributes between full irrigation and no irrigation. The medium to late maturing varieties RB92579 and SP81‑3250 have higher stalk and sugar yield and better water use efficiency, and are recommended for studies on sugarcane response to irrigation

Qualidade de agregados em solo ácido tratado com gesso

A aplicação de gesso em solos ácidos é um manejo agrícola recomendado para reduzir teores elevados de Al3+ e aumentar teores baixos de Ca2+. Contudo, poucos estudos têm sido realizados para avaliar seu efeito sobre a qualidade dos agregados, principalmente de solos intemperizados, que possuem naturalmente uma elevada agregação. Nesses solos, a substituição do Al3+ por Ca2+ no complexo de troca pode provocar dispersão e redução da agregação do solo. Esse estudo teve por objetivo avaliar o efeito da aplicação de gesso agrícola na qualidade da agregação de um Argissolo Amarelo ácido. Para isso foram aplicadas cinco doses de gesso agrícola (0, 2, 4, 6 e 8 Mg ha-1). O experimento foi realizado em campo em delineamento em blocos ao acaso com cinco tratamentos e quatro repetições. Nós avaliamos o índice de estabilidade dos agregados e também a percentagem, diâmetro médio geométrico e diâmetro médio ponderado dos agregados, bem como a macro e microporosidade do solo. Houve redução em torno de 5% na percentagem de agregados com diâmetro entre 1,0-0,5 mm com a aplicação de gesso agrícola, indicando perda na qualidade dos agregados

INGESTIVE BEHAVIOR OF BUFFALOES FED INCREASING LEVELS OF CONCENTRATE IN SUGARCANE BASED DIETS

The experiment was conducted to evaluate the ingestive behavior of buffalo fed sugarcane with different levels of concentrate. Twenty four Murrah buffaloes with body weight of 219±23 kg and nine months old were assigned to completely randomized design. Animals were placed in individual pens where they received diets ad libitum, twice a day. The experimental period has divided into 30 d for adaptation and 84 d for observations and samples collection. Four treatments were used: 1) 80% sugarcane (SC) + 20% concentrate (C); 2) 60% SC + 40% C; 3) 40% SC + 60% C; 4) 20% SC + 80% C. The diets were isoproteics and urea/ammonium sulfate was used at 9:1 ratio to correct the protein level of sugarcane. The evaluated variables were time spent feeding (TSF), ruminating (TSR), idle (TSI), dry matter intake (DMI), feeding efficiency of dry matter (FEDM), rumination efficiency of dry matter (REDM), number of meals, duration of meal and duration of breaks between meal. A regression analysis was performed using the MIXED procedure. DMI was positively affected (P0.05) on TSF. However, the TSR and number of meals decreased linearly (

Porte da gramínea e inclusão da cunhã modificam o valor nutritivo da silagem de capim-elefante

The objective of this work was to evaluate the nutritional value of silages from tall-sized and dwarf elephant grass (Pennisetum purpureum) genotypes, intercropped or not with butterfly pea (Clitoria ternatea). The experiment was performed in randomized complete blocks, in a 4x2 factorial arrangement (four genotypes × two cropping systems). The genotypes intercropped or not with butterfly pea were: IRI-381 and Elephant B, tall sized; and Taiwan A-146 2.37 and Mott, dwarf. Forage was harvested 60 days after regrowth. In the silage from Mott grass intercropped with butterfly pea, lower contents of lignin (78.1 g kg-1), neutral detergent fiber (636.0 g kg-1), and neutral detergent insoluble protein (13.15 g kg-1), besides a greater dry matter recovery (873.3 g kg-1), were observed. The silage from Taiwan A-146 2.37 intercropped with the legume showed a greater crude protein content (136.1 g kg-1). In both silages, the ammonia nitrogen contents were quite reduced (26.4 g kg-1). However, greater residual water-soluble carbohydrate contents were observed in the silages from the intercrop (1.85 mg g-1) and from the Mott grass monocrop (1.51 mg g-1). Moreover, there was a lower in vitro dry matter digestibility (676.7 g kg-1) for the silage from the intercrop. Dwarf genotypes increase the nutritional value of elephant grass silage, compared with the tall-sized ones. Intercropping with butterfly pea improves silage fermentation characteristics, despite reducing its digestibility. Therefore, the ensilage of dwarf Mott elephant grass intercropped with butterfly pea shows more promising results.O objetivo deste trabalho foi avaliar o valor nutritivo de silagens de genótipos anões e altos de capim-elefante (Pennisetum purpureum), consorciados ou não à cunhã (Clitoria ternatea). O experimento foi realizado em delineamento de blocos ao acaso, em arranjo fatorial 4x2 (quatro genótipos × dois sistemas de plantio). Os genótipos consorciados ou não à cunhã foram: IRI-381 e Elefante B, de porte alto; e Taiwan A-146 2.37 e Mott, anões. A forragem foi colhida após 60 dias de rebrota. Na silagem do capim Mott consorciado à cunhã, foram observados menores teores de lignina (78,1 g kg-1), fibra em detergente neutro (636,0 g kg-1) e proteína insolúvel em detergente neutro (13,15 g kg-1), além de maior recuperação da matéria seca (873,3 g kg-1). A silagem de Taiwan A-146 2.37 cultivado em consórcio com a leguminosa apresentou maior teor de proteína bruta (136,1 g kg-1). Em ambas as silagens, os teores de nitrogênio amoniacal foram bastante reduzidos (26,4 g kg-1). No entanto, maiores teores residuais de carboidratos solúveis em água foram observados nas silagens do consórcio (1,85 mg g-1) e do capim Mott em monocultivo (1,51 mg g-1). Além disso, houve menor digestibilidade in vitro da matéria seca (676,7 g kg-1) na silagem do consórcio. Os genótipos anões aumentam o valor nutricional da silagem de capim-elefante, comparados aos de porte alto. O consórcio com a cunhã melhora as características fermentativas da silagem, apesar de reduzir a sua digestibilidade. Portanto, a ensilagem do capim anão Mott consorciado à cunhã apresenta resultados mais promissores