Indicadores de produção de soja no Rio Grande do Sul comparados ao zoneamento agrícola

Melo, Ricardo Wanke de; Fontana, Denise Cybis; Berlato, Moacir Antônio

doi:10.1590/s0100-204x2004001200002

Cited by 14 publications

(19 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Rainfall was apparently well distributed along the growth period in both years ( Fig. 1), but mean daily temperatures of the second year were lower than in the first, which explains the decrease in soybean yield as this climatic variable seems to be the most important controlling factor for soybean development in the region (Melo et al 2004). In the second year sorghum was used in place of maize and the registered yield indicated no effect of climate on this crop.…”

Section: Discussionmentioning

confidence: 96%

Fluxes of nitrous oxide from soil under different crop rotations and tillage systems in the South of Brazil

Jantalia

Santos

Urquiaga

et al. 2008

Nutr Cycl Agroecosyst

183

View full text Add to dashboard Cite

The zero tillage (ZT) system is used in a large area ([24 Mha) of crop production in Brazil. This management system can contribute to soil C sequestration, but many studies in other countries have registered greater nitrous oxide emissions under ZT compared to conventional tillage (CT), which may reduce greenhouse gas mitigation benefits. The aim of this study was to estimate the emission of N 2 O from cropping systems under conventional and zero tillage in an 18-year-old experiment conducted on a Rhodic Ferralsol in the South of Brazil. Fluxes of N 2 O were measured over two years using staticclosed chambers in the two tillage systems with three crop rotations. Soil water filled pore space (%WFPS) and soil mineral N were monitored along with rainfall and air temperature. Estimates of N 2 O emissions were obtained by integrating the fluxes with time and also by applying the IPCC direct emission factor (EF1 = 1%) to the amounts of N added as fertilisers and returned as crop residues. Fluxes of N 2 O were relatively low, apart from a short period at the beginning of measurements. No relationship between N 2 O fluxes and %WFPS or mineral N were observed. Nitrous oxide emissions were not influenced either by tillage system or crop rotation. For the crop rotation receiving high rates of N fertiliser in the second year, field-measured N 2 O emissions were significantly underestimated by the IPCC emission factor 1 (EF1). For the other treatments measured N 2 O emissions fell within the EF1 uncertainty range, but always considerably lower than the EF1 estimate, which suggests IPCC EF1 overestimates true N 2 O emissions for the Ferralsol under evaluation.

show abstract

Section: Discussionmentioning

confidence: 96%

Fluxes of nitrous oxide from soil under different crop rotations and tillage systems in the South of Brazil

Jantalia

Santos

Urquiaga

et al. 2008

Nutr Cycl Agroecosyst

183

View full text Add to dashboard Cite

show abstract

“…In the Rio Grande do Sul State (RS), the large inter-annual variability of rainfall is mainly due to El Niño and La Niña occurrences, which cause yield fluctuations in southern Brazil [20]- [22]; there, the most impacted crops are usually soybean and maize [20] in the summer. Prolonged drought effects on the summer crop in 2005 caused a decrease of approximately 75% in the soybean grain production [23].…”

Section: Introductionmentioning

confidence: 99%

Monitoring Heat Waves and Their Impacts on Summer Crop Development in Southern Brazil

Gusso¹,

Ducati²,

Veronez³

et al. 2014

View full text Add to dashboard Cite

Periods in the soybean summer cycle that are sensitive to the occurrence of high temperatures were studied. An analysis was performed on the variability of soybean yields associated with crop canopy temperatures during key development periods. A land surface temperature (LST) data series from MODIS (Moderate Resolution Imaging Spectroradiometer) on the Aqua satellite was processed between 2003 and 2012 that covered the entire state of Rio Grande do Sul, in Brazil. Enhanced vegetation index (EVI) data from MODIS on the Terra satellite were used to monitor the LST during different phenological stages. Spatially interpolated maps of soybean yield distributions were generated using data obtained from Instituto Brasileiro de Geografia e Estatística (IBGE) at state and municipality levels. The results indicate that canopy-LST occurrence in mid-February, during the grain filling, is most correlated to yield reduction (R 2 = 0.82 and RMSD = 14.4%). At the state level, the average yield is 2003 kg•ha − 1 with a standard deviation of 308 kg•ha −1. The overall average of the canopy-LST is 305.0 K (31.8˚C) with a standard deviation of 1.9 K. The slope of the downward linear relationship between canopy-LST and yield was −28.7%. These results indicate that monitoring heat wave events can provide important information for characterising agriculture vulnerability.

show abstract

“…Isso pode indicar que a perda de produtividade, por ocorrência de estiagem, pode estar associada ao efeito acoplado de duas forçantes distintas nas safras analisadas, ou seja, uma redução inicial na disponibilidade hídrica, seguida de um aumento da temperatura, agravada pelas condições de troca de energia, em função, principalmente, do vento, da umidade do ar e da exposição à radiação incidente (Nemani & Running, 1997;Wan et al, 2004;Peterson et al, 2012). Nessa situação, a implementação de estratégias e políticas públicas de planejamento, quanto a época de semeadura e à utilização de técnicas de irrigação, como apontado em Melo et al, (2004), são extremamente importantes, considerando-se que ondas de calor possam ter intensidade potencializadas pela ocorrência de estiagem inibindo a atividade fotossintética (Carmo-Silva et al, 2012).…”

Section: Resultsunclassified

“…No Estado do Rio Grande do Sul (RS), a grande variabilidade interanual da precipitação, verificada em função, principalmente, dos fenômenos El Niño e La Niña, é o principal fator responsável pelas oscilações de produtividade na região sul (Buriol et al, 1977, Fontana et al, 2002, Melo et al, 2004, Ferreira, 2006, sendo que as culturas mais afetadas geralmente são as da soja e do milho (Fontana et al, 2002) na safra de verão.…”

Section: Introductionunclassified

Integração de imagens NOAA/AVHRR: rede de cooperação para monitoramento nacional da safra de soja

Gusso

2013

Rev. Ceres

View full text Add to dashboard Cite

An early assessment of national crop development conditions while the plants are still in the fields is highly needed to calculate correctly projections for decision-making and policies related to government planning and food security. The aim of this study was to evaluate the suitability of NOAA /AVHRR (National Oceanic and Atmospheric Administration / Advanced Very High Resolution Radiometer) to detect changes in vegetation conditions, due to water stress during soybean crop, by means a combination of Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI). Both LST and NDVI data were combined and compared in a pixel basis over a soybean crop area in Rio Grande do Sul State. The predicted theoretical inverse relationship for the combination of LST and NDVI was detected. An average increase of LST was observed in a normal crop cycle ( from 301.02 K to 308.36 K) compared to a crop cycle under water stress condition. An average reduction in NDVI was observed for normal crop cycle development (from 0.65 to 0.53) compared to a crop cycle under drought-induced effects. It was observed a higher correlation of municipality yield with LST (R2=0.78) than NDVI (R2=0.59). Results obtained indicate that the aggregation of AVHRR images, from Uma avaliação inicial das condições do desenvolvimento da safra nacional, enquanto as plantas ainda estão nos campos, é altamente necessária para o cálculo correto das projeções na tomada de decisão e políticas relacionadas com o planejamento governamental e segurança alimentar. O objetivo deste trabalho foi avaliar a adequação dos dados NOAA/AVHRR (National Oceanic and Atmospheric Administration / Advanced Very High Resolution Radiometer) em detectar mudanças nas condições da vegetação, devidas à ocorrência de estresse hídrico, na soja, por meio de uma combinação do índice NDVI (Normalized Difference Vegetation Index) e da LST (Land Surface Temperature). Os dados LST e NDVI foram combinados e comparados pixel a pixel, sobre uma área de cultivo de soja, no Rio Grande do Sul. A relação teórica inversa prevista na combinação de LST e NDVI foi detectada. Foi observado que ocorre um aumento médio na LST em uma safra de ciclo normal (de 301,02 K para 308,36 K), quando comparada a uma safra sob condição de estresse hídrico, no desenvolvimento da cultura. Uma redução média do NDVI foi observada no ciclo normal (de 0,65 para 0,53), comparada com uma safra sob efeitos ocasionados pela estiagem no desenvolvimento da cultura. Foi observado maior correlação da produtividade municipal com LST (R2=0,78) do que com o NDVI (R2 = 0,59). Os resultados obtidos indicam que a integração de imagens do sensor AVHRR, proveniente de diferentes instituições, proporciona a adequada combinação espacial e temporal dos dados LST e NDVI, a fim de detectar a ocorrência de estresse hídrico, bem como sua intensidade, caracterizando as condições do ciclo de desenvolvimento da soja.Palavras-chave: sensoriamento remoto, estiagem, temperatura da superfície terrestre, índice de vegetação.

show abstract

Indicadores de produção de soja no Rio Grande do Sul comparados ao zoneamento agrícola

Cited by 14 publications

References 0 publications

Fluxes of nitrous oxide from soil under different crop rotations and tillage systems in the South of Brazil

Fluxes of nitrous oxide from soil under different crop rotations and tillage systems in the South of Brazil

Monitoring Heat Waves and Their Impacts on Summer Crop Development in Southern Brazil

Integração de imagens NOAA/AVHRR: rede de cooperação para monitoramento nacional da safra de soja

Contact Info

Product

Resources

About