Test and analysis of agrometeorological models for predicting coffee (C. arabica L.) crop production based on soil water availability

O cafeeiro arábica é afetado nos seus diversos estádios fonológicos pelas condições meteorológicas, em especial pela disponibilidade hídrica do solo, a qual se constitui no principal condicionante de sua produtividade. Além desse tipo de condicionamento, as condições de clima interferem na bienalidade produtiva, na qualidade do produto e na sustentabilidade dessa cultura. Essa bienalidade de produção do cafeeiro em função das variáveis climáticas, tem sido pouco estudada apesar de sua importância. Modelos matemáticos agrometeorológicos que relacionam a fenologia, a bienalidade e a produtividade do cafeeiro variedade Mundo Novo foram desenvolvidos e testados para as condições do Estado de São Paulo, durante os anos agrícolas de 1951/52 a 1962/63 em Campinas, de 1983/84 a 1992/93 em Gália e de 1966/67 a 1973/74 em Mococa. Os modelos baseiam-se na penalização da produtividade potencial em função da produtividade do ano anterior e das relações ER/EP (evapotranspiração real e potencial) derivados de balanços hídricos decendiais sequenciais ocorridos durante estádios fonológicos, considerando 16 combinações diferentes. A penalização é feita à medida que haja restrição hídrica para a planta durante os diferentes estádios fonológicos, considerando coeficientes (ky) de resposta da planta ao suprimento hídrico e índices (λ) de sensibilidade ao fator hídrico obtidos a partir de modelos aditivos ou multiplicativos. Inicialmente a produtividade do ano anterior não foi considerada nos modelos, porém o desempenho obtido nas parametrizações foi ruim, já que a acentuada oscilação anual da produtividade não permite a correlação das variáveis nas regressões lineares. Com a inclusão da produtividade do ano anterior, representada pelo coeficiente (ky0) e índice (λ0), houve melhora significativa nos coeficientes de determinação (R2) em todos os locais considerados. Os melhores resultados provenientes do teste dos modelos considerando análise geral para as três localidades foram obtidos pelo modelo aditivo, para a combinação trimestral ago/set/out (dormência das gemas/início do florescimento), nov/dez/jan (florescimento/formação do grão) e fev/mar/abr (formação do grão/maturação). As magnitudes dos valores de ky1 e ky2 revelaram que a produtividade do cafeeiro é particularmente sensível ao estresse hídrico durante os estádios fenológicos do florescimento e formação do grão. Os coeficientes relativos à produtividade do ano anterior (kyO) apresentaram, em todos os locais, grande influência sobre a produtividade na maioria das combinações.This study describes a new method to reliably monitor and assess drought propable impact on coffee yields just before the beginning of the maturation growth stage. A good model requires the evaluation of the sensitive indices and test for a specific variety and region. Phenological and yield data for Mundo Novo cultivar were taken from experiments conducted at Campinas (1951/63), Mococa (1967/74), and Gália (1983/93) Instituto Agronômico Experimental Stations The models tested are based in the penalization of the crop yield potential according the previous yield and the ER/EP relation (actual/potential evapotranspiration) derived by 10-day soil water balance occurred during different growth stages. These ratios were weighted by derivation of crop phase yield-response coeficients (ky values) and sensitive indices (λ values) in additive and multiplicative type models. Based on the model' s statistics, the additive type models presented better performance than the multiplicative type models. The additive model which considers the crop phases combination (D3): "bud dormancy/flowering beginning" (Aug/Sep/Oct), "flowering/grain formation" (Nov/Dec/Jan) and "grain formation/maturation" (Jan/Feb/Mar) presented the best performance. An analysis of the ky values show that this combination gives higher weigth to the water relations during the flowering and grain formation (fruit set). Toe previous yield coeficients presented (ky0) high values for all models tested

Environmental Land Use Conflicts in a Macroscale River Basin: A Preliminary Study Based on the Ruggedness Number

Inadequate land use planning is one of the main driving forces leading to the occurrence of erosion and environmental degradation. The negative impacts of poor planning influence soil physical quality and fertility, agricultural productivity, water quality and availability, biodiversity and other ecosystem services. In some areas, actual land use is not consistent with potential use. When this occurs, the area is termed as being in environmental land use conflict. Many studies have demonstrated the efficiency of the ruggedness number (RN) method for determining land use potential in watersheds. The RN method is simple and can be carried out using geographic information systems (GIS). However, the absence of potential land use or agricultural land suitability assessments is recurrent in territorial management plans or integrated water resources plans (IWRP), especially for macroscale river basins. Therefore, the aim of this preliminary study is to identify possible environmental land use conflicts at the Rio Grande Basin (BHRG), Brazil, using the Ruggedness Number. The results indicate high agricultural use potential and the predominance of appropriate or acceptable soil use at the BHRG. However, class 1, 2 and 3 environmental conflicts were identified in some Rio Grande sub-basins, suggesting greater environmental degradation risks. The findings clearly indicate that more exhaustive studies on environmental quality (soil capability, water, biodiversity) are required at the BHRG, especially in environmental land use conflict areas. We emphasize that this is an important preliminary study which may be carried out in any other macroscale hydrographic basin

Vegetation index from MODIS sensor to estimate sugarcane yield

The contribution of sugarcane crop to provide raw material to produce sugar and also alcohol as an alternative energy source has been relevant to the economic growth of Brazil. Therefore, the availability of precise agricultural production information about this crop is important for planning and decision-making in the entire productive chain. The present work has the objective to estimate sugarcane yield in crop fields during the crop years 2004/2005 and 2005/2006, based on an agronomic model fit with orbital data. The innovation of this model consists in the use of the leaf area index (LAI) estimated from the NDVI (Normalized Difference Vegetation Index) produced by the MODIS sensor (Moderate Resolution Imaging Spectroradiometer) on board of the Terra satellite from NASA (National Aeronautics Space Administration). The agronomic model explained 31% and 25% of the yield variability among crop fields for the crop years 2004/2005 and 2005/2006, respectively, which is mainly attributed to use of NDVI images from MODIS. The model output should be useful to improve the precision of the crop yield estimation forecast performed in loco.A participação da cultura da cana-de-açúcar no fornecimento de matéria prima para produção de açúcar e também de álcool, como fonte alternativa de energia, tem sido relevante para o crescimento econômico do Brasil. Consequentemente, a disponibilidade de informações precisas sobre a produção agrícola dessa cultura é importante para auxiliar no planejamento e na tomada de decisões em toda a cadeia produtiva. O presente trabalho teve como objetivo estimar a produtividade agrícola de talhões de cana-de-açúcar para as safras 2004/2005 e 2005/2006, a partir de um modelo agronômico ajustado com dados orbitais. A inovação deste modelo consiste no uso do índice de área foliar (IAF) estimado a partir do produto índice de vegetação NDVI (Normalized Difference Vegetation Index) do sensor MODIS (Moderate Resolution Imaging Spectroradiometer) a bordo do satélite Terra da NASA (National Aeronautics Space Administration). O modelo agronômico explicou 31% e 25% da variação da produtividade observada entre talhões nos anos safra 2004/2005 e 2005/2006, respectivamente, o que se deve fundamentalmente ao uso das imagens NDVI do MODIS. O resultado do modelo pode ser usado para auxiliar e aprimorar a previsão da estimativa da produtividade feita in loco.78979

Monitoring Biennial Bearing Effect on Coffee Yield Using MODIS Remote Sensing Imagery

Coffee is the second most valuable traded commodity worldwide. Brazil is the world’s largest coffee producer, responsible for one third of the world production. A coffee plot exhibits high and low production in alternated years, a characteristic so called biennial yield. High yield is generally a result of suitable conditions of foliar biomass. Moreover, in high production years one plot tends to lose more leaves than it does in low production years. In both cases some correlation between coffee yield and leaf biomass can be deduced which can be monitored through time series of vegetation indices derived from satellite imagery. In Brazil, a comprehensive, spatially distributed study assessing this relationship has not yet been done. The objective of this study was to assess possible correlations between coffee yield and MODIS derived vegetation indices in the Brazilian largest coffee-exporting province. We assessed EVI and NDVI MODIS products over the period between 2002 and 2009 in the south of Minas Gerais State whose production accounts for about one third of the Brazilian coffee production. Landsat images were used to obtain a reference map of coffee areas and to identify MODIS 250 m pure pixels overlapping homogeneous coffee crops. Only MODIS pixels with 100% coffee were included in the analysis. A wavelet-based filter was used to smooth EVI and NDVI time profiles. Correlations were observed between variations on yield of coffee plots and variations on vegetation indices for pixels overlapping the same coffee plots. The vegetation index metrics best correlated to yield were the amplitude and the minimum values over the growing season. The best correlations were obtained between variation on yield and variation on vegetation indices the previous year (R = 0.74 for minEVI metric and R = 0.68 for minNDVI metric). Although correlations were not enough to estimate coffee yield exclusively from vegetation indices, trends properly reflect the biennial bearing effect on coffee yield

Monitoring biennial bearing effect on coffee yield using modis remote sensing imagery

Coffee is the second most valuable traded commodity worldwide. Brazil is the world’s largest coffee producer, responsible for one third of the world production. A coffee plot exhibits high and low production in alternated years, a characteristic so called biennial yield. High yield is generally a result of suitable conditions of foliar biomass. Moreover, in high production years one plot tends to lose more leaves than it does in low production years. In both cases some correlation between coffee yield and leaf biomass can be deduced which can be monitored through time series of vegetation indices derived from satellite imagery. In Brazil, a comprehensive, spatially distributed study assessing this relationship has not yet been done. The objective of this study was to assess possible correlations between coffee yield and MODIS derived vegetation indices in the Brazilian largest coffee-exporting province. We assessed EVI and NDVI MODIS products over the period between 2002 and 2009 in the south of Minas Gerais State whose production accounts for about one third of the Brazilian coffee production. Landsat images were used to obtain a reference map of coffee areas and to identify MODIS 250 m pure pixels overlapping homogeneous coffee crops. Only MODIS pixels with 100% coffee were included in the analysis. A wavelet-based filter was used to smooth EVI and NDVI time profiles. Correlations were observed between variations on yield of coffee plots and variations on vegetation indices for pixels overlapping the same coffee plots. The vegetation index metrics best correlated to yield were the amplitude and the minimum values over the growing season. The best correlations were obtained between variation on yield and variation on vegetation indices the previous year (R = 0.74 for minEVI metric and R = 0.68 for minNDVI metric). Although correlations were not enough to estimate coffee yield exclusively from vegetation indices, trends properly reflect the biennial bearing effect on coffee yield

Validação de dados termopluviométricos obtidos via sensoriamento remoto para o Estado de São Paulo Validation of temperature and rainfall data obtained by remote sensing for the State of Sao Paulo, Brazil

Dados termopluviométricos são utilizados em diversos estudos. Contudo, a escassez de dados resultante da baixa densidade de estações meteorológicas é um problema frequentemente encontrado. Com isto, a utilização de dados estimados por satélites tem-se mostrado importante para regiões nas quais eles são escassos. Neste trabalho foram realizadas comparações entre dados mensais de precipitação pluvial estimados pelo satélite TRMM e de temperatura, estimados pelo satélite Aqua/MODIS aos dados observados por estações de superfície, para diferentes localidades do Estado de São Paulo, no período de 2003 a 2010. Os resultados demonstraram que para os dados de precipitação pluvial os menores erros foram observados nos meses de inverno e os maiores nos meses de verão. Em relação aos dados de temperatura observou-se que, com a inclusão de um fator de correção, os dados do satélite Aqua apresentaram boa exatidão em todos os meses. De maneira geral, os resultados obtidos indicam que os satélites TRMM e Aqua são alternativas eficientes na aquisição de informações em locais onde há falhas ou escassez dos mesmos podendo ser também utilizados na análise da consistência de dados coletados por meio de redes meteorológicas.<br>Temperature and rainfall data are used in several scientific studies. However, the paucity of data resulting from the low density of weather stations is a problem frequently encountered in these studies. Thus, the use of estimated data from satellites has become an important tool in regions where they are scarce. In this study comparisons were made between monthly rainfall data estimated by TRMM satellite and temperature data estimated by the satellite Aqua/MODIS data observed by surface stations, for different locations in the State of Sao Paulo during the period 2003 to 2010. The results showed that for the rainfall data, smaller errors were observed during the winter and higher during the summer months. In relation to the temperature data it was observed that with the inclusion of the correction factor, the Aqua satellite data showed good accuracy in all months. Overall, the results obtained by validation of the data of rain and temperature, indicating that the satellite TRMM and Aqua are efficient alternatives for obtaining information of locations where there are errors or shortage of the same, may also be used to analyse the consistency of data collected by meteorological networks

Water Sustainability at the River Grande Basin, Brazil: An Approach Based on the Barometer of Sustainability

Water resources are fundamental for the social and economic development of a country and sustainability is the best approach to treat water-related problems. Therefore, sustainability studies of water resources are deemed urgent. Sustainability analysis methods should enable space-temporal monitoring, decision-making, and development of policies necessary for water governance. Furthermore, sustainability analysis methods should also integrate environment and socioeconomic variables into a single system. In this context, this study aimed to assess the water sustainability conditions of the River Grande Basin (BHRG), Brazil, before the implementation of the Integrated Water Resources Plan (IWRP), using the Barometer of Sustainability tool (BS). The River Grande basin was in an &#8220;almost unsustainable&#8222; condition and under high environmental stress. A significant imbalance between environmental and human well-being in the system was also observed. To achieve an acceptable sustainability condition, it is thus necessary to improve the environmental quality of the area. Among the priority thematic area, native vegetation recovery was the most urgent. Overall, the sustainability study based on the BS not only facilitates comprehension regarding environment and human interrelationships, but also provide references for policy formulations and water management