Papers by Mellissa Ananias Soler da Silva
DOAJ (DOAJ: Directory of Open Access Journals), Aug 1, 2009
Pesquisa Agropecuária Tropical
Most studies about soil organic carbon stock changes in the Cerrado (Brazilian Savanna) biome are... more Most studies about soil organic carbon stock changes in the Cerrado (Brazilian Savanna) biome are either related to field data collected in clayey Ferralsols or different land uses, as if they were in equilibrium. This study aimed to evaluate the effect of tillage systems and crop sequences on the soil organic carbon stock and crop yield, in a sandy Ferralsol from Bahia, Brazil. The experimental design was randomized blocks, with four replicates. Soil samples were collected after fve years of cotton, soybean and maize monocropping under heavy disk harrow and leveling harrow (conventional tillage), and of crop rotation of cotton, soybean and maize with green manure or cover crop (no-tillage). Additional samples were collected from a non-cultivated site (Neotropical Savanna, Cerrado sensu stricto). Soil conservation practices such as no-tillage and crop rotation with cover crop and green manure favored the soil organic carbon stock at the 0-40 cm layer, with the highest values reachin...
Todos os direitos reservados. A reprodução não autorizada desta publicação, no todo ou em parte, ... more Todos os direitos reservados. A reprodução não autorizada desta publicação, no todo ou em parte, constitui violação dos direitos autorais (Lei nº 9.610).
Functions of Natural Organic Matter in Changing Environment, 2012
Biochar incorporation into the soil is a proposed C sequestration strategy. How newly applied bio... more Biochar incorporation into the soil is a proposed C sequestration strategy. How newly applied biochar affects C accumulation in the soil is therefore a relevant question. This study presents part of the results, obtained from field experiments, of a study which has as objective to contribute to elucidate this question. The results indicated that biochar application into the soil directly influences humic substance levels. This effect is most probably due to the dichromate oxidable C contained in the biochar itself. This abstract and the abstract by Novotny et al. in this anais are containing complementary information as the latter characterized the HS fractions extracted from the same samples of the sandy loam discussed in this abstract.
Revista Ceres, Dec 1, 2019
The proper nitrogen management is required to achieve high irrigated rice yield. This study aimed... more The proper nitrogen management is required to achieve high irrigated rice yield. This study aimed to determine the rice response to nitrogen topdressing doses and calibrate the chlorophyll meter reading. Three experiments were conducted in a randomized block design. In the first experiment, five N rates (0, 30, 60, 90, and 120 kg ha-1) were evaluated as the first, and 30 kg ha-1 N as the second topdressing, which were combined with the application of 30 kg ha-1 N as the first and five N rates, as the second topdressing. The other experiments assessed the application of 30 kg ha-1 of N, as the first, and four N rates (0, 40, 80, and 120 kg ha-1), as the second topdressing. There was a response to N application, with maximum technical efficiency reaching 33 kg ha-1 in the first and between 40 and 50 kg ha-1 in the second topdressing. The chlorophyll meter was sensitive to estimate the amount of N to be applied in topdressing, using the nitrogen sufficiency index (NSI). To each percent unit of NSI below 95%, one should apply 10 kg ha-1 of N as the first and 2-3 kg ha-1 of N as the second topdressing.
Revista Ceres, Aug 1, 2022
This study aimed to analyze rice straw alternative managements to maximize the rice-soybean succe... more This study aimed to analyze rice straw alternative managements to maximize the rice-soybean succession yield and to quantify their impacts on soil properties. The experiment was set up in a completely randomized design with six replicates. Nine rice straw managements were evaluated: straw burning (M1), straw harvesting (M2), straw incorporation with disc harrow and two passes (M3) or three passes (M4) of leveling disc harrow, straw incorporation with kniferoller and soybean no-tillage (M5), straw incorporation with knife-roller and two passes (M6) or three passes (M7) of leveling disc harrow, straw incorporation with two passes of knife-roller and two passes (M8) or three passes (M9) of leveling disc harrow. Straw incorporation by knife-roller provided the lowest soil organic matter (SOM) contents due to slow mineralization of fresh straw incorporated shallow into the soil, although SOM increased in the surface layer related to the initial content. Rice-soybean succession yield was more affected by the physical than by the soil chemical properties. The straw incorporation with one pass of knife-roller and two passes of leveling disc harrow (M6) can replace the straw burning, without affecting the rice-soybean succession yield and soil physical quality, with a reduction in machinery operations, allowing early soil tillage.
Frontiers in sustainable food systems, Jul 22, 2022
Irrigation strategies are keys to fostering sustainable and climate-resilient rice production by ... more Irrigation strategies are keys to fostering sustainable and climate-resilient rice production by increasing efficiency, building resilience and reducing Greenhouse Gas (GHG) emissions. These strategies are aligned with the Climate-Smart Agriculture (CSA) principles, which aim to maximize productivity whilst adapting to and mitigating climate change. Achieve such mitigation, adaptation, and productivity goals-to the extent possible-is described as climate smartness. Measuring climate smartness is challenging, with recent progress focusing on the use of agronomic indicators in a limited range of contexts. One way to broaden the ability to measure climate-smartness is to use modeling tools, expanding the scope of climate smartness assessments. Accordingly, and as a proof-of-concept, this study uses modeling tools with CSA indicators (i.e., Greenhouse Intensity and Water Productivity) to quantify the climate-smartness of irrigation management in rice and to assess sensitivity to climate. We focus on a field experiment that assessed four irrigation strategies in tropical conditions, Continuous Flooding (CF), Intermittent Irrigation (II), Intermittent Irrigation until Flowering (IIF), and Continuous soil saturation (CSS). The DNDC model was used to simulate rice yields, GHG emissions and water inputs. We used model outputs to calculate a previously developed Climate-Smartness Index (CSI) based on water productivity and greenhouse gas intensity, which score on a scale between−1 (lack of climate-smartness) to 1 (high climate smartness) the climate-smartness of irrigation strategies. The CSS exhibited the highest simulation-based CSI, and CF showed the lowest. A sensitivity analysis served to explore the impacts of climate on CSI. While higher temperatures reduced CSI, rainfall mostly showed no signal. The climate smartness decreasing in warmer temperatures was associated with increased GHG emissions and, to some extent, a reduction in Water Productivity (WP). Overall, CSI varied with the climate-management interaction, demonstrating that climate variability can influence the performance of CSA practices. We conclude that combining models with climate-smart indicators can broaden Arenas-Calle et al. Climate-Smartness Assessment of Irrigated Rice the CSA-based evidence and provide reproducible research findings. The methodological approach used in this study can be useful to fill gaps in observational evidence of climate-smartness and project the impact of future climates in regions where calibrated crop models perform well.
Agri-Environmental Sciences, Jun 14, 2021
O manejo apropriado da água de irrigação está entre as técnicas necessárias para atingir não apen... more O manejo apropriado da água de irrigação está entre as técnicas necessárias para atingir não apenas alto potencial produtivo como também maior eficiência no uso de água e insumos nos sistemas agrícolas irrigados. Objetivou-se com este estudo determinar a influência do manejo da irrigação no desempenho agronômico de cultivares de arroz irrigado e na eficiência de uso da água, em várzeas tropicais. O estudo foi constituído por três experimentos: um, conduzido no Campo Experimental da Unitins, em Formoso do Araguaia, TO em Plintossolo Háplico distrófico; e dois experimentos foram realizados na Fazenda Palmital, da Embrapa Arroz e Feijão, no município de Goianira, GO, em Gleissolo Háplico distrófico. Foram avaliados quatro manejos de água: Inundação contínua-IC (método convencional, com lâmina de água contínua durante todo ciclo); Irrigação intermitente em todo ciclo-II; Irrigação intermitente até a floração, após contínua-IIF e Solo saturado-SS (solo mantido acima da capacidade de campo, mas sem lâmina de água), e quatro cultivares BRS Pampeira, BRS Catiana, BRS A702 CL e IRGA 424. O delineamento experimental usado foi o inteiramente casualizado, com cinco repetições, no esquema de parcelas divididas, constituídas pelos quatro manejos de água, e as subparcelas pelas cultivares. Os resultados mostraram que o manejo da irrigação solo saturado propicia produtividade média de grãos das cultivares de arroz irrigado similar ou superior em até 16% ao manejo tradicional de água com inundação contínua e com redução de até 82% do volume de água aplicado, o que resulta em maior eficiência de uso da água. O manejo solo saturado e irrigação intermitente constituem estratégias para racionalizar o uso dos recursos hídricos na orizicultura.
Revista Caatinga, Sep 1, 2022
Residues from turkey production are often used as fertilizers in pastures near producing regions.... more Residues from turkey production are often used as fertilizers in pastures near producing regions. These residues can contribute to the increase of carbon and nitrogen stocks in the soil. This study aimed to evaluate the cumulative effects of nine applications of turkey litter rates on C and N fractions and stocks in a Latossolo Vermelho distroférrico (Oxisol) cultivated under rotational grazing. The experimental area was divided into 16 pickets of 0.5 ha each and cultivated with Urochloa decumbens in a rotational grazing system. The treatments consisted of accumulated doses of turkey litter (38.3; 54.8 and 69.2 Mg ha-1), with applications carried out between 2008 and 2017, in addition to a control treatment, without application of this material. After nine years of application, total organic carbon (TOC) and total nitrogen (TN) stocks in the soil increased as turkey litter rates increased, reaching increments in the 0-0.2 m layer of 11.2 Mg ha-1 and 1.03 Mg ha-1 , respectively, when compared to the control treatment. In the same 0-0.2 m layer, the maximum increments in carbon stock in particulate organic matter (POC) and nitrogen stock in particulate organic matter (N-POM) were obtained with the estimated total doses of 62 and 66 Mg ha-1 , respectively. In addition to increasing the amount, the use of turkey litter improved the quality of the carbon present in the soil, since the carbon management index, in the 0-0.2 m layer, was increased by 124% when using the highest accumulated dose.
Revista Ceres
This study aimed to analyze rice straw alternative managements to maximize the rice-soybean succe... more This study aimed to analyze rice straw alternative managements to maximize the rice-soybean succession yield and to quantify their impacts on soil properties. The experiment was set up in a completely randomized design with six replicates. Nine rice straw managements were evaluated: straw burning (M1), straw harvesting (M2), straw incorporation with disc harrow and two passes (M3) or three passes (M4) of leveling disc harrow, straw incorporation with kniferoller and soybean no-tillage (M5), straw incorporation with knife-roller and two passes (M6) or three passes (M7) of leveling disc harrow, straw incorporation with two passes of knife-roller and two passes (M8) or three passes (M9) of leveling disc harrow. Straw incorporation by knife-roller provided the lowest soil organic matter (SOM) contents due to slow mineralization of fresh straw incorporated shallow into the soil, although SOM increased in the surface layer related to the initial content. Rice-soybean succession yield was more affected by the physical than by the soil chemical properties. The straw incorporation with one pass of knife-roller and two passes of leveling disc harrow (M6) can replace the straw burning, without affecting the rice-soybean succession yield and soil physical quality, with a reduction in machinery operations, allowing early soil tillage.
Pesquisa Agropecuária Brasileira, 2021
The objective of this work was to evaluate the economic viability and competitiveness of upland r... more The objective of this work was to evaluate the economic viability and competitiveness of upland rice (Oryza sativa), compared with flooded rice, in a system with different nitrogen fertilization timing and cover crops in Southeastern Brazil. The treatments consisted of upland rice grown under Urochloa brizantha or Urochloa ruziziensis straw, with the following fertilization: T, 30 kg ha-1 N at rice sowing + no extra N supply (0 kg ha-1); C, 30 kg ha-1 N at rice sowing + 90 kg ha-1 N at rice tillering; A2, 30 kg ha-1 N at rice sowing + 90 kg ha-1 N one day before rice sowing; and A1, 30 kg ha-1 N at rice sowing + 90 kg ha-1 N in the living cover crops. Total operating cost, gross revenue, operating profit, profitability index, and equilibrium price were determined. Upland rice results in a monetary gain for the farmer similar to that of flooded rice when nitrogen is added, regardless of fertilization timing. Under rainfall deficit conditions, upland rice sown on U. brizantha straw shows higher profitability rates than when sown on U. ruziziensis. When there is a possibility of rainfall deficit, U. brizantha, as a cover plant, results in a greater economic security for upland rice producers.
The objective of this study was to reflect and debate on a significant topic of agricultural rese... more The objective of this study was to reflect and debate on a significant topic of agricultural research: its role in society. The study intended to deliberate over the recent changes proposed in the Sistema Embrapa de Gestao – SEG (Embrapa’s management system) regarding the management of Research and Development (R&D) agenda. This agenda aims to connect Embrapa with society, verifying the impacts of research and innovation results in problem solving, promotion of agricultural development and sustainability for the benefit of Brazilian society. It also intends to verify whether this target can be achieved and recognized by the country’s citizens. To accomplish this task, the Nucleus project was analyzed, taking into account the scope of the objectives, goals and results and their relationship with Embrapa’s innovation management model. Final considerations seek to show that the proposed change is an improvement in comparison to the previous system. However, there are some issues that n...
O presente teve por objetivo avaliar os impactos, resultantes da aplicacao de vinhaca em fertirri... more O presente teve por objetivo avaliar os impactos, resultantes da aplicacao de vinhaca em fertirrigacao no cultivo de cana-de-acucar no efluente de colunas de solo, alem de quantificar as especies ionicas ocorrentes no solo derivadas de sua utilizacao, bem como a movimentacao no perfil ao longo do tempo. Foram utilizadas amostras de solos de duas areas distintas sendo que a primeira area era cultivada com cana-de-acucar ha 21 anos e na segunda predominava mata nativa nao antropizada. As amostras foram trazidas para a Casa de Vegetacao da Escola de Agronomia e Engenharia de Alimentos (EA/UFG) e montaramse dois experimentos paralelos: 1o) as amostras acondicionadas em colunas de PVC com 120 cm de altura por 25 cm de diâmetro revestidas internamente com sacos de rafia, com uma planta de cana-de-acucar cada. Os tratamentos consistiram de diferentes doses de vinhaca aplicadas as colunas de solo: 0, 300, 600 e 1200 m3 ha-1. Foram realizadas quatro coletas de efluente das colunas (0, 60, 90...
AGRI-ENVIRONMENTAL SCIENCES, 2021
O manejo apropriado da água de irrigação está entre as técnicas necessárias para atingir não apen... more O manejo apropriado da água de irrigação está entre as técnicas necessárias para atingir não apenas alto potencial produtivo como também maior eficiência no uso de água e insumos nos sistemas agrícolas irrigados. Objetivou-se com este estudo determinar a influência do manejo da irrigação no desempenho agronômico de cultivares de arroz irrigado e na eficiência de uso da água, em várzeas tropicais. O estudo foi constituído por três experimentos: um, conduzido no Campo Experimental da Unitins, em Formoso do Araguaia, TO em Plintossolo Háplico distrófico; e dois experimentos foram realizados na Fazenda Palmital, da Embrapa Arroz e Feijão, no município de Goianira, GO, em Gleissolo Háplico distrófico. Foram avaliados quatro manejos de água: Inundação contínua – IC (método convencional, com lâmina de água contínua durante todo ciclo); Irrigação intermitente em todo ciclo – II; Irrigação intermitente até a floração, após contínua – IIF e Solo saturado – SS (solo mantido acima da capacidade...
O Seminario Jovens Talentos e um evento realizado anualmente pela Embrapa Arroz e Feijao, cujos o... more O Seminario Jovens Talentos e um evento realizado anualmente pela Embrapa Arroz e Feijao, cujos objetivos sao divulgar os trabalhos desenvolvidos pelos bolsistas e estagiarios juntamente com seus orientadores, incentivando a troca de informacoes cientificas na Embrapa e, possibilitando aos estudantes a pratica da escrita cientifica e da apresentacao oral em publico, preparando-os para seu futuro profissional.
Revista Ceres, 2019
The proper nitrogen management is required to achieve high irrigated rice yield. This study aimed... more The proper nitrogen management is required to achieve high irrigated rice yield. This study aimed to determine the rice response to nitrogen topdressing doses and calibrate the chlorophyll meter reading. Three experiments were conducted in a randomized block design. In the first experiment, five N rates (0, 30, 60, 90, and 120 kg ha-1) were evaluated as the first, and 30 kg ha-1 N as the second topdressing, which were combined with the application of 30 kg ha-1 N as the first and five N rates, as the second topdressing. The other experiments assessed the application of 30 kg ha-1 of N, as the first, and four N rates (0, 40, 80, and 120 kg ha-1), as the second topdressing. There was a response to N application, with maximum technical efficiency reaching 33 kg ha-1 in the first and between 40 and 50 kg ha-1 in the second topdressing. The chlorophyll meter was sensitive to estimate the amount of N to be applied in topdressing, using the nitrogen sufficiency index (NSI). To each percent unit of NSI below 95%, one should apply 10 kg ha-1 of N as the first and 2-3 kg ha-1 of N as the second topdressing.
Acta Scientiarum. Agronomy, 2019
Sustainable production systems, such as the no-tillage system (NTS), have a tendency to increase ... more Sustainable production systems, such as the no-tillage system (NTS), have a tendency to increase organic carbon in the soil. However, in Brazilian cotton production, the conventional tillage system (CTS) is predominant, and long-term studies on cotton crop under the NTS are scarce. The present study aimed to evaluate the effect of soil management and crop rotation systems on the cotton fiber yield as well as on the carbon and nitrogen accumulation in the soil. This study was conducted in the Brazilian savanna over 9 years and consisted of the following four treatments with different soil management systems: the NTS and CTS with the succession or rotation of crops (cotton, soybean, maize, and Urochloa ruziziensis). The NTS increased the carbon content by 55% in the top 5 cm after 9 years and increased the carbon stock by approximately 20% at a depth of up to 40 cm. Crop rotation with soybean, maize, and cotton was insufficient to increase the carbon stock in the soil under the CTS. I...
Geoderma, 2017
Biochar may increase soil fertility and crop yield by enhancing soil organic carbon (SOC), nutrie... more Biochar may increase soil fertility and crop yield by enhancing soil organic carbon (SOC), nutrient availability and water retention. However, the mechanisms through which biochar effects crop yield at field scale and the time span over which biochar can affect soil properties and crop yield are still little known. The aim of this study was to evaluate the effect of wood biochar as soil amendment, combined with the application of synthetic fertilizer in a zero-tillage system, on soil physical-chemical properties and soybean grain yield in a 5-year field trial settled on a sandy clay loam Haplic Ferralsol of the Brazilian savannah. Immediately after biochar application (year 0), soil pH and plant available water (PAW) increased and Al 3+ and bulk density (BD) decreased linearly with biochar application rate. Later, in year 5, biochar had no effect for PAW and BD increased with biochar rates. The SOC was not affected until the third year after application, but increased linearly with biochar rates at 4 and 5 years after its application. Macro-porosity (MAC) was affected in a quadratic manner reaching a maximum at 8 Mg ha −1 biochar rate in years 0 and 2, however in year 5 it decreased with increasing biochar rates. Soybean grain yield increased with biochar rates until the third year after its application. There was almost no interaction effect of biochar and synthetic fertilizer; except for potassium (K +) availability and grain yield in year 3. Possible control mechanisms of biochar effect on soybean grain yield through its effect on soil fertility and physical-hydraulic properties are discussed. The effect of biochar on soybean yield depended on multiple independent factors that included soil and environmental variables. Because of this its effect on yield was variable through the years, which makes it rather unpredictable. Biochar, however, may have an important contribution to sustainable production through enhancing the effect of conservation soil management, like the use of green manure or mulching, on SOC accumulation.
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Papers by Mellissa Ananias Soler da Silva