Search

Made available in DSpace on 2021-06-25T10:54:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-06-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) No-till (NT) farming is a major soil conservation strategy. In the Brazilian Cerrado, soybean is the main grain crop, and strategies that improve the cultivation of cover crops in the off-season in succession to soybean could facilitate NT for large cultivated areas. In the municipality of Nova Xavantina, MT, Brazil, three experiments were carried out in a randomized block design with four replications. This work aimed to evaluate the establishment of Urochloa ruziziensis (ruzigrass) in succession to soybean as a function of ruzigrass seed treatment, sowing density and phenological stage, and soybean cultivar allelopathic potential. In the first experiment, treatment of ruzigrass seeds with six doses (0, 150, 300, 450, 600 and 750 mL of commercial product 100 kg−1 of seeds) of fipronil + thiophanate-methyl + pyraclostrobin was evaluated. In the second experiment, two ruzigrass interseeding periods (soybean phenological stages R5.5 and R7) and five ruzigrass seed densities (4.3, 6.4, 8.6, 10.7 and 12.9 kg ha−1 VPS) were tested. In the third experiment, the interference of soybean cultivars in the establishment of ruzigrass and the potential allelopathic effect of the cultivars on forage germination were evaluated, six soybean cultivars RR (Roundup Ready®) were used: P98Y70; TMG 115; TMG 132; M 8527; P98Y11; TMG 123. Our results showed that seed treatment facilitated forage establishment in the interseeding system, and the use of high sowing rates at phenological stage R5.5 of soybean promoted greater ruzigrass plant development. The effects of the soybean cultivars on ruzigrass germination varied, suggesting allelopathic effects of the deposition of petioles and soybean leaves on ruzigrass seeds. Thus, an appropriate interseeding strategy can improve forage production in the off-season and favor NT through correct management of forage establishment in succession to soybean. São Paulo State University (UNESP) College of Agricultural Sciences Dep. of Crop Science Lageado Experimental Farm, P.O. Box: 237 Agronomy Graduate Program Seed Reserach Laboratory São Paulo Western University, Raposo Tavares HWY, Km 572 Advanced Studies Group in Weed Science (NAPD/UEM) Brazilian Agricultural Research Corporation (EMBRAPA), Righway of Pioneiros MT-222, Km 2,5 Special Academic Unit of Agricultural Sciences Federal University of Goiás (UFG) Mato Grosso State University (UNEMAT), Rod, BR 158, km 650 São Paulo State University (UNESP) College of Agricultural Sciences Dep. of Crop Science Lageado Experimental Farm, P.O. Box: 237

Made available in DSpace on 2022-04-28T19:45:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-02-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Empresa Brasileira de Pesquisa Agropecuária Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) In sustainable tropical agriculture, grass-legume intercropping can increase productivity, enhance the nutritional quality of the crop and affect soil microbiological activity, leading to higher yields in succession crops. This study evaluated the impact of grass-legume intercropping, during the pasture phase of integrated crop-livestock systems under no-tillage (ICLS–NT), on soil microbiota, pasture quality, and soybean productivity in the Brazilian Cerrado. We evaluated the effect of intercropping on total soil contents of organic carbon and nitrogen, soil microbial activity, animal and soybean productivity (2017 and 2018 crop seasons), and pasture production and quality. The experiment consisted of twelve treatments under grass-legume intercropping in the pasture phase of ICLS–NT. The grasses Urochloa ruziziensis ‘Kennedy’, U. brizantha ‘Paiaguás’, Panicum maximum ‘Tamani’ and U. brizantha ‘Piatã’ were grown in monoculture and intercropped with cowpea (Vigna unguiculata) ‘Tumucumaque’ or pigeon pea (Cajanus cajan) ‘Mandarin’. A randomized block design, with three repetitions, was used in a split-plot arrangement, considering the grasses as plots and the legumes as subplots. The results showed that ICLS–NT improved the activity of soil microbial biomass when compared to monoculture systems. Grass-legume intercropping during the pasture phase, mainly with cowpea (Vigna unguiculata), increased soybean productivity, and grass dry matter. Total organic carbon (TOC), carbon management index (CMI%), microbial biomass carbon (MBC), soil basal respiration (BR), and metabolic quotient (Qmic) are the most sensitive markers when it comes to the effects of intercropping on soil microbiological activity and soybean productivity in ICLS–NT. Identifying the best grass-legume combinations allows the establishment of more productive crop-livestock integration systems under no-tillage better adapted to the bio-edaphoclimatic conditions of the Brazilian Cerrado. Rondonópolis Federal University (UFR) School of Agricultural and Veterinarian Sciences São Paulo State University (UNESP) Universidade Federal do Rio Grande do Sul (UFRGS) Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Federal University of Paraná (UFPR) School of Agricultural and Veterinarian Sciences São Paulo State University (UNESP) CNPq: 454461/2014-3

Aims The integrated crop-livestock systems (ICLS) under no-tillage improves soil fertility of the Brazilian Cerrado. We aimed to evaluate the effect of different grass-legume intercropping compared to single grass cultivation in the off-season of an ICLS on (i) soil organic carbon (C) and nitrogen (N) pools, (ii) soil microbial biomass and activity, (iii) soil enzymatic activity, and (iv) soybean grain yield in succession. Methods The field study was conducted in an on-farm experiment in 2016/17 and 2017/18 cropping seasons. The soybean was cultivated in the summer season, with the subsequent treatments in the off-season, using two grasses (Urochloa ruziziensis and U. brizantha), single or intercropped with Cowpea (Vigna unguiculata) or Pigeon pea (Cajanus cajan). We evaluated soil organic C and N pools, microbial biomass and activity, enzyme activity, and soybean yield. Results Cowpea intercropping yielded 24% more soybeans than grasses single cropped. There was a higher microbial biomass and activity, and enzymatic activity in the soil under grass-legume intercropping. In addition to the lower basal respiration and microbial metabolic quotient (qCO2), the greater microbial quotient (qMIC) and microbial biomass C indicate a higher soil microbial C utilization efficiency under grass-legume intercropping. The soil total organic C and N stocks increased under Pigeon pea intercropping by 16% and 27%, respectively, compared to single grasses. Conclusions Grass-legume intercropping in the pasture phase of ICLS is an additional tool to maximize soybean yields in the short term. The intercropping effects on soybean yield were directly related to soil quality improvements through soil biological and biochemical properties.

The combination of grain and livestock production in integrated Crop-Livestock systems (iCLs) provide the opportunity to increase yields, improve soil attributes and ensure the sustainability of the agricultural system. The objective of this research was to evaluate the impact of seven land use systems on their microbiota. Five iCL systems were implemented in 2005 in Santa Carmem, MT, Brazil, with different rotating crops: iCL A (soybean/maize, preceded by two years with pasture), iCL B (rice/maize, preceded by two years with soybean/intercropped pasture), iCL C (soybean/maize, preceded by three years with pasture), iCL D (pasture/maize, preceded by five soybean/maize or millet intercropped with pasture) and iCL E (pasture/maize, preceded by three years with pasture). These were compared with two reference systems: a conventional soybean/maize succession system (CC) and native forest (NF). Soils were collected (0.00-0.20 m) and the population dynamics of fungi, bacteria, actinobacteria and cellulolytic microorganisms were evaluated over the course of two years (2012 and 2013). Likewise, carbon stocks of microbial biomass (CBM); metabolic quotient (qCO2); basal respiration (RB); acid (AP) and alkaline (ALP) phosphatases; β-glycosidase (BG) and urease of soil were assessed. The iCLs systems improved the performance of soil microbiota compared to the conventional system. The rotation of legume and grasses preceded by pasture in iCL A and C, increased the total fungi, bacteria, actinobacteria, enzymatic activity and CBM stocks. This fact contributed to an increased efficiency in environmental performance and added greater sustainability to the system. RESUMO A combinação da produção de grãos e gado em sistemas de integração Lavoura-Pecuária (iLPs) oferece a oportunidade de aumentar a produtividade, melhorar os atributos do solo e a sustentabilidade do sistema agropecuário. O objetivo dessa pesquisa foi avaliar o impacto de sete sistemas de uso do solo sobre a sua microbiota. Cinco sistemas de iLPs foram implementados em 2005 em Santa Carmem, MT, Brasil, com diferentes culturas rotativas: iLP A (soja/milho, precedidos por dois anos com pastagem), iLP B (arroz/milho, precedidos por dois anos com soja/milho consorciado com pastagem), iLP C (soja/milho, precedidos por três anos com pastagem), iLP D (pastagem/milho, precedidos por cinco soja/milho ou milheto consorciados com pastagem) e iLP E (pastagem/milho, precedidos por três anos com pastagem). Estes foram comparados com dois sistemas: um sistema convencional de sucessão soja/milho (CC) e a mata nativa (NF). Os solos dos sete sistemas foram coletados (0,00-0,20 m) e avaliados por dois anos (2012 e 2013) quanto a dinâmica das populações de fungos, bactérias, actinobactérias e micro-organismos celulolíticos; estoques de carbono da biomassa microbiana (CBM); quociente metabólico (qCO2); respiração basal (RB); fosfatases ácida (AP) e alcalina (ALP); β-glicosidase (BG) e urease do solo. Os sistemas de iLPs melhoraram o desempenho da microbiota do solo em comparação ao sistema convencional. A rotação de leguminosas e gramíneas precedidas por pastagem nas iLPs A e C, promoveu aumentos nos: totais de fungos, bactérias, actinobactérias, atividade enzimática e estoques de CBM. Esse fato contribuiu para uma maior eficiência no desempenho ambiental e agregou maior sustentabilidade ao sistema.

Integrated farming systems (IS) are one of the main strategies of the Brazilian government to reduce or compensate for carbon emissions from agriculture with simultaneous improvement in production efficiency. The IS are agricultural production systems that combine crop, livestock and forestry activities in the same area. The aim of this study was to address soil organic carbon (SOC) stocks under two agriculture areas with IS, in comparison with one exclusively used as low-input pasture (Pasture). The IS consisted of growing forestry species (Eucalyptus urograndis) simultaneously with soybean (Glycine max) and aerobic rice (Oryza sativa) for 2 years when grain crops were followed by palisade grass (Urochloa bryzantha). The study was carried out in real farm conditions in the southern Amazon ecosystem, north of Mato Grosso State, Brazil. SOC stocks were measured to 1 m soil depth. Compared to Pasture, areas of higher SOC stocks were identified in IS under the tree lines below 0.3 m, where there was no soil N deficiency. Our results indicated that, under the local edaphic and climatic conditions of the study, IS with trees can promote SOC accumulation even in a short term, such as 3 years in this case study, if soil fertility constraints do not exist.

Made available in DSpace on 2020-12-10T19:45:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-02-01 Fundacao de Apoio a Pesquisa do Estado de Mato Grosso Rede ILPF Empresa Brasileira de Pesquisa Agropecuaria (Embrapa) Soil organic carbon (SOC) is the main terrestrial carbon reservoir. The spatial distribution of SOC is mainly regulated by environmental factors and anthropogenic activity. Historically, land-use change has been responsible for much of the world's greenhouse gas emissions. However, carbon storage can be improved through agricultural management, either by increasing carbon inputs through higher crop yields or by delaying the release of carbon into the atmosphere. Therefore, it is essential to correctly choose which cover crops to use and how long these crops will remain in the crop rotation system. In order to clarify these issues, the objective of this work was to evaluate the chemical quality and changes in soil carbon stock between no-tillage and soybean/com crop succession systems and integrated crop-livestock systems. The study was carried out in Querencia (MT), Brazil, located in the Cerrado/Amazon ecotone. The integrated systems were studied between 2007 and 2014. These systems followed annual crop rotation and forage rotation, and were laid out as a consortium or were isolated, with the aim of producing grain and meat. In order to determine soil chemical properties, 170 sampling plots were randomized among the treatments. The highest carbon values were observed in the integrated crop-livestock systems (ICL), probably due to higher inputs of organic residues. Crop rotation with plants of different families allowed better land use and soil exploration. However, integrated production systems comprising longer pasture periods, no-tillage, and soybean/corn crop succession decreased soil carbon. When comparing carbon stocks from 2010 to 2014, only integrated production systems ICL2 and ICL3 were able to increase carbon stocks. Our results highlight the importance of length of growing and correct choice of cover crops in maintaining SOC stocks, and thus provide insights to improve SOC stocks in agricultural land in Brazil's main producing region. Univ Sao Paulo, Luiz de Queiroz Coll Agr, Dept Soil Sci, BR-13418900 Piracicaba, Brazil Univ Fed Mato Grosso UFMT, Inst Ciencias Agr & Ambientais, BR-78557267 Sinop, Brazil Brazilian Agr Res Comporat Embrapa, BR-70770901 Brasilia, DF, Brazil Sao Paulo State Univ Julio de Mesquita Filho, Dept Plant Hlth Rural Engn & Soils, BR-15385000 Ilha Solteira, Brazil Brazilian Agr Res Comporat Embrapa, BR-78550970 Sinop, Brazil Sao Paulo State Univ Julio de Mesquita Filho, Dept Soils & Fertilizers, BR-14884900 Jaboticabal, Brazil Brazilian Agr Res Comporat Embrapa, BR-86001970 Londrina, Parana, Brazil Sao Paulo State Univ Julio de Mesquita Filho, Dept Plant Hlth Rural Engn & Soils, BR-15385000 Ilha Solteira, Brazil Sao Paulo State Univ Julio de Mesquita Filho, Dept Soils & Fertilizers, BR-14884900 Jaboticabal, Brazil Fundacao de Apoio a Pesquisa do Estado de Mato Grosso: FAPEMAT. 0561074/2016

Arbuscular mycorrhizal fungi (AMF) are important microorganisms that act as sensitive soil quality indicators. The increase in plant diversity in Integrated Crop Livestock Systems under no-tillage (ICLS-NT) can also alter the diversity of species of fungi and bring benefits to the system. This study had the objective of evaluating the AMF diversity and its quantitative characteristics in ICLS-NT with intercrop in the pasture phase. The experiment was conducted in a dystrophic red latosol, with plots represented by the grasses Panicum maximun cv. BRS Tamani and Urochloa brizantha cv. Piata, intercrop with the legumes (subplots): cowpea (Vigna unguiculata) cv. BRS Tumucumaque, pigeon pea (Cajanus cajan) cv. BRS Mandarim and single grass type only. The potential for inoculation was elevated in areas with legume intercrop, with either grass, and about 29% higher in areas with the C. cajan/P. maximun consortium. They may be associated with the benefits that the intercrop with legumes brings, through the relationship of rhizobia and AMF. The spore density and mycorrhizal colonization were higher with the use of grass from the genus Urochloa in relation to Panicum, reaching 92% and 88% higher, respectively, as well as an increase in species richness, being associated with a greater affinity of AMF with intercropped grasses. The insertion of the legumes into the intercrop with the grasses affected soybean productivity, positively correlating (74%) with mycorrhizal colonization. These results are related to the fact that intercrop promote the release of a high diversity of organic compounds, helping in the activity of soil microbiota, including AMF, increasing colonization and species diversity of these fungi. Thus, intercrops of grasses with legumes affected positively the activity and diversity of species of the AMF, reflecting in the increase in productivity of the soybean crop.

The aim of the present study was to assess the growth and energetic properties of genetic material of eucalyptus grown in several integrated crop-livestock system spatial arrangements in Barra-do-Garças City (MT). The genetic material of 76-month old Eucalyptus spp from eight spatial arrangements were assessed according to the following properties: diameter, height and volume growth, mortality rate, dry matter yield, sapwood to heartwood ratio, form factor, bark volume, basic density, superior calorific value, ash content, volatile matter, fixed carbon and trunk energy. Data analysis was performed by adjusting growth function, test for model identity and parameters equality and ANOVA tests to Scott-Knott’s mean clustering test. Eucalyptus grandis x E. urophylla clones from recorded the highest energy efficiency due to their high yield volume, which was decisive to determine estimated energy available per tree and cropland area. Growth, stem shape and basic density varied among, and within, the same genetic materials, depending on their respective spatial arrangement. However, solid biomass properties (high calorific value, ash content, fixed carbon and volatile matter) remained stable.

Sistemas integrados vêm se tornando comuns em várias regiões do Brasil e estudos sobre os efeitos desses sistemas nos atributos do solo têm-se intensificado. Contudo, ainda há dúvidas sobre seus impactos no ambiente, devido ao uso e manejos aplicados, como o tráfego de máquinas e pisoteio animal. Este trabalho foi realizado com objetivo de detectar alterações nos atributos físicos, químicos e biológicos do solo após implantação de sistemas de integração lavoura-pecuária-floresta (iLPF) e identificar aqueles adequados para a detecção na mudança da qualidade do solo. Foram coletadas amostras de solo nas camadas de 0-0,10 m em Nova Canãa do Norte, MT, e em Cachoeira Dourada, GO, em áreas sob iLPF com uma (iLPF1) ou três (iLPF3) linhas de eucalipto por renque e em áreas de pastagem recuperada e degradada. Nas áreas sob iLPF, as amostragens foram feitas em diversas posições em relação à linha de árvores. A maior qualidade física do solo sob iLPF1 e sob pastagem recuperada foi responsável pela sua discriminação dos demais ambientes. O teor de potássio, o carbono e o nitrogênio da biomassa microbiana e a respiração basal do solo foram eficientes em discriminar a pastagem degradada dos sistemas integrados e da pastagem recuperada. Os sistemas integrados, com três ou quatro anos de implantação, contribuíram para melhorar a qualidade física do solo, mas ainda não foram capazes de interferir marcadamente na sua qualidade biológica em relação à pastagem degradada. Made available in DSpace on 2019-09-14T00:46:30Z (GMT). No. of bitstreams: 1 CNPAF2019ra.pdf: 900278 bytes, checksum: fcc133840bce736394a2d55228658f50 (MD5) Previous issue date: 2019

Made available in DSpace on 2019-10-03T17:31:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-11-01. Added 1 bitstream(s) on 2019-10-04T16:20:28Z : No. of bitstreams: 1 S0100-204X2018001101248.pdf: 516532 bytes, checksum: 0b69cbb8ec4a9d035e6fd21058fa0950 (MD5) Resumo: O objetivo deste trabalho foi avaliar a qualidade do solo e sua relação com a produtividade de soja (Glycine max) em sistema de integração lavoura-pecuária (ILP), com consórcio entre gramíneas e leguminosas na fase pastagem. O experimento foi realizado no Estado de Mato Grosso, em um Latossolo Vermelho distrófico, em que gramíneas (Megathyrsus maximus 'BRS Tamani' e Urochloa brizantha 'BRS Piatã'), consorciadas com feijão-caupi (Vigna unguiculata 'BRS Tumucumaque') e feijão-guandu (Cajanus cajan 'BRS Mandarim'), foram cultivadas após a colheita da soja. Um delineamento experimental de blocos ao acaso foi utilizado com três repetições, em arranjo de parcelas subdivididas, em que as gramíneas foram consideradas como parcelas, e as leguminosas, como subparcelas. Os consórcios com leguminosas proporcionaram incrementos dos estoques de C e N total. Os consórcios causaram o aumento de C e N da biomassa microbiana, enquanto os cultivos solteiros contribuíram para o estresse da microbiota do solo. A atividade da enzima urease foi sensível às alterações de manejo em curto prazo, porém a fosfatase ácida e a β-glucosidase foram indicadores pouco sensíveis. A qualidade do solo é elevada com os consórcios entre gramíneas e leguminosas, com efeitos positivos sobre a produtividade de grãos de soja. Abstract: The objective of this work was to evaluate the quality of the soil and its relation with soybean (Glycine max) yield in an integrated crop-livestock system (ICLS), with intercropping between grasses and legumes in the pasture phase. The experiment was carried out in the state of Mato Grosso, Brazil, on a dystrophic Oxisol, in which grasses (Megathyrsus maximus 'BRS Tamani' and Urochloa brizantha 'BRS Piatã'), intercropped with cowpea (Vigna unguiculata 'BRS Tumucumaque') and pigeon pea (Cajanus cajan 'BRS Mandarim'), were cultivated after soybean harvest. A randomized complete block design was used, with three replicates, in a split-plot arrangement, in which grasses were considered as plots, and legumes as subplots. Legume intercrops provided increases of C and total N stocks. The intercrops caused the increase of C and N of the microbial biomass, whereas the single cultures contributed to stress in the soil microbiota. The activity of the urease enzyme was sensitive to management changes in the short term, but acid phosphatase and β-glucosidase were poorly sensitive indicators. Soil quality is high with intercropping between grasses and legumes, with positive effects on soybean grain yield. Universidade Federal de Mato Grosso Embrapa Agrossilvipastoril Universidade Federal de Lavras Departamento de Ciência do Solo Universidade Estadual Paulista Universidade Estadual Paulista

The production systems of upland rice culture in Mato Grosso are not consolidated yet while the effects of soil physical properties and their correlation with rice yield in crop-livestock integrated systems are not defined as well. Therefore, this study determined the spatial variability of physical properties of soil and rice cultivated in no-tillage system under different cover crops, using principal components analysis and geostatistics. The experiment was conducted in Santa Carmen, northern Mato Grosso. A regular grid with 100 sample points distributed in an area of 26,400 m2 was installed. Soil and rice samples were collected to determine rice variables and soil physical properties. The average rice yield was 1.70 Mg∙ha−1, ranging from 0.70 to 3.12 Mg∙ha−1. The highest yields were observed in consortium with cowpea and brachiaria and were associated with lower incidence of grain spots, despite higher soil density and penetration resistance. The consortium with brachiaria, crotalaria, and sudangrass had lower yields, which was associated with higher incidence of grain spots, despite higher soil macroporosity and total porosity. RESUMO A cultura do arroz de terras altas no Mato Grosso ainda não está consolidada nos sistemas de produção, tampouco estão definidos os efeitos dos atributos físicos do solo e a correlação destes com a produtividade do arroz em sistemas de integração lavoura-pecuária. Diante disso, o objetivo do trabalho foi determinar a variabilidade espacial dos atributos físicos do solo e da cultura do arroz em semeadura direta sob diferentes plantas de cobertura, utilizando-se técnicas de análise de componentes principais e geoestatística. O experimento foi realizado no município de Santa Carmem, norte do Estado de Mato Grosso. Uma malha regular com 100 pontos foi instalada em uma área de 26.400 m2. Amostras de solo e de planta foram coletadas nos pontos da malha para a caracterização dos atributos físicos do solo e agronômicos do arroz. A produtividade média do arroz após os consórcios de braquiária com feijão-caupi, crotalária e campim-sudão foi de 1,70 Mg∙ha−1, com elevada variabilidade, com valor mínimo de 0,70 Mg∙ha−1 e máximo de 3,12 Mg∙ha−1. No consórcio de feijão-caupi e braquiária, o solo apresentou as maiores densidades e resistências à penetração, que não foram restritivos à produtividade do arroz, sendo verificados nesse consórcio as maiores produtividades, que se correlacionaram com a menor incidência de mancha de grãos. Nos demais consórcios, observaram-se menores produtividades, que foram correlacionadas negativamente com a maior incidência de mancha de grãos; entretanto, o solo apresentou maiores valores de macroporosidade e porosidade total.

The integrated systems are management practices that maximize the area use through the integration of crops with forest species. Impacts on the microbial biomass in an integrated crop-livestock-forest (iCLF) system are evaluated. The latter consists of simple, double and triple rows of eucalyptus and soil with soybean/pasture alternation with a native forest for comparison. Soil was collected at a depth of 0-0.05 m during the rainy and dry periods (March and October/2010). Evaluated microbiological indexes were biomass carbon, basal respiration, metabolic and microbial quotients, activity of acid and alkaline phosphatase enzymes and ?-glucosidase. General means of biomass microbial carbon and microbial quotients were higher during the dry period, whereas variables basal respiration and metabolic quotients were higher during the rainy period, and in both cases activities in iCLF soil with single eucalyptus rows. Enzyme activities were more stable in integrated crop-livestock-forest soil between the two periods and slightly higher than the other systems. As a rule, iCLF systems had a positive impact on the microbiology of soil.

Periodic assessment of the genetic progress made in recurrent selection programs is essential for assessing the evolution of the programs and identifying the main factors that have contributed to this progress. This study aimed to estimate genetic progress in grain yield, plant height and days-to-flowering achieved in the CNA6 population of upland rice (Oryza sativa L.), after four cycles of recurrent selection; and evaluate the genetic potential of this population to generate superior inbred lines after each selection cycle. The experimental data were obtained from progeny yield trials of each recurrent selection cycle. These trials were carried out in two or three locations per cycle, and consisted of S0:2 progenies and at least three checks. Federer?s augmented block design, with one replication on location (the environment), was adopted. Results revealed genetic progress for grain yield and plant height, with total genetic gains of 375.87 kg ha−1 and -3.90 cm, respectively, during the four selection cycles. The annual relative gain observed for grain yield was 1.54 %. The genetic potential of the population was analysed by the expected proportion of superior inbred lines. The standard adopted as the limit for obtaining superior inbred lines was the average of the checks for each trait. The genetic potential for grain yield and plant height increased during the study period. For days-to-flowering, no genetic gain occurred; however, the genetic potential of the population to generate superior inbred lines for this trait was maintained after the selection cycles.

Objetivou-se avaliar o desempenho produtivo e econômico de animais consumindo quatro suplementos diferenciados pelos níveis crescentes de grão de milheto em substituição ao grão de milho, assim como analisar as características nutricionais do pasto de Brachiaria brizantha cv. Marandu em sistema de integração lavoura e pecuária. Foram utilizados 64 novilhos, não castrados, sendo 32 mestiços (Holandês x Nelore) e 32 da raça Nelore, com média de idade de 20 meses e o peso corporal médio inicial de 388 ± 26kg. A área experimental constituiu-se de quatro piquetes de 4,68ha, formados com B. brizantha cv. Marandu. A massa de forragem total e a massa de forragem potencialmente digestível foram de 5,24t/ha e 3,39t/ha, respectivamente. O experimento foi estruturado segundo um esquema fatorial (2x4) distribuído em delineamento inteiramente casualizado, onde foram avaliados dois grupos genéticos e quatro diferentes níveis de grão de milheto em substituição ao grão de milho na formulação dos suplementos (0%; 33%; 66% e 100%). A quantidade ofertada de suplemento foi de 4,0kg/animal/dia. Houve efeito de grupo genético sobre o ganho produtivo dos animais, sendo que novilhos Nelore apresentaram melhor desempenho. O ganho de peso médio diário, ganho de peso total e peso corporal final, reduziram linearmente com a substituição do alimento energético grão de milho por grão de milheto nos suplementos. A inclusão de 33% de grão de milheto em suplementos concentrados promove redução nos dias necessários para a obtenção de animais de peso corporal de 450kg. The objective was to evaluate the performance and economic development of animals receiving four supplements differentiated by the levels of grain of millet as replacement for corn grain, as well as assess nutritional characteristics of pasture of Brachiaria brizantha cv. Marandu in integrated crop and livestock. Used 64 steers, uncastrated, 32 crossbred (Holstein x Nelore) and 32 Nelore, with 20 months average age and 388 ± 26kg initial body weight. The experiment consisted of four paddocks of 4.68 ha, formed by B. brizantha cv. Marandu. The availability of dry matter and potentially digestible dry matter was 5.24t/ha and 3.39t/ha, respectively. The work was designed as a factorial arrangement (2x4) in a completely randomized design to evaluate two genetic groups and four different levels of grain instead of millet to maize grain in the formulation of supplements (0%; 33%; 66% e 100%). The quantity supplied of 4.0kg/animal/day. A significant effect of genetic group on productive performance of animals, and that Nelore steers have better performance. The average daily weight gain, total weight gain and final body weight decreased linearly with the inclusion of millet in supplements. The replacement of 33% of the corn grain millet concentrated supplements promotes reduction in the days required to obtain animal body weight of 450kg.

Amsterdam; International audience; Changes in land use can result in either sources or sinks of atmospheric carbon (C), depending on management practices. In Brazil, significant changes in land use result from the conversion of native vegetation to pasture and agriculture, conversion of pasture to agriculture and, more recently, the conversion of pasture and agriculture to integrated crop-livestock systems (ICL). The ICL system proposes a diversity of activities that include the strategic incorporation of pastures to agriculture so as to benefit both. In agricultural areas, for example, the implementation of ICL requires the production of quality forage for animals between crops as well as the production of straw to facilitate the sustainability of the no-tillage (NT) management system. The objective of this study was to evaluate the modifications in soil C stocks resulting from the main processes involved in the changes of land use in Amazonia and Cerrado biomes. For comparison purposes, areas under native vegetation, pastures, crop succession and ID. under different edapho-climatic conditions in Amazonia and Cerrado biomes were evaluated. This study demonstrated that the conversion of native vegetation to pasture can cause the soil to function either as a source or a sink of atmospheric CO(2), depending on the land management applied. Non-degraded pasture under fertile soil showed a mean accumulation rate of 0.46 g ha(-1) year(-1). Carbon losses from pastures implemented in naturally low fertile soil ranged from 0.15 to 1.53 Mg ha(-1) year(-1), respectively, for non-degraded and degraded pasture. The conversion of native vegetation to agriculture in areas under the ICL system, even when cultivated under NT, resulted in C losses of 1.31 in six years and of 0.69 Mg ha(-1) in 21 years. The conversion of a non-degraded pasture to cropland (soybean/sorghum) released, in average, 1.44 Mg of C ha(-1)year(-1)to the atmosphere. The ICL system in agricultural areas has shown evidences that it always functions as a sink of C with accumulation rates ranging from 0.82 to 2.58 Mg ha(-1) year(-1). The ICL produces soil C accumulation and, as a consequence, reduces atmospheric CO(2) in areas formerly cultivated under crop succession. However, the magnitude of C accumulation in soil depends on factors such as the types of crops, the edapho-climatic conditions and the amount of time the area is under ICE

Currently, agricultural productivity and sustainable development are the desired bases for the creation of production systems. Farming for greater production and the efficient use of soil resources are at the core of modern systems. However, the way in which agricultural management and practices can change soil quality has become increasingly important. The aim of this study was to detect changes in soil biological properties caused by implementation of the integrated crop-livestock-forest system (iCLF) and to identify the properties suitable for detecting changes in soil biological quality. Soil samples were collected from the 0.00-0.10 m layer in Nova Canaã do Norte, MT, Brazil, and Cachoeira Dourada, GO, Brazil, in areas of the iCLF with 1 (iCLF1) or 3 (iCLF3) eucalyptus rows and in areas of recovered and degraded pasture. In Cachoeira Dourada, in the iCLF1, samples were taken in the tree row and at 2.5, 5.0, and 10.0 m from this row. In Nova Canaã in the iCLF3, samples were taken in the center row and at 3.0, 6.0, 9.0, and 12.0 m from this row. In Cachoeira Dourada, samples were taken in the center row and at 1.5, 3.0, 4.5, 6.0, and 9.0 m from this row. All samples had five replicates. In Nova Canaã, the iCLF1 caused less disturbance in the microbial population than the degraded pasture, which was evidenced by the lower metabolic quotient and basal respiration. The sampling position in relation to the tree row had little effect on comparison of the iCLF with the degraded pasture in regard to soil biological properties. Carbon and N of the microbial biomass and the microbial quotient were the best properties for differentiating the iCLF from the degraded pasture. ICLFs have not yet led to improvements in soil biological quality in relation to the degraded pasture.