Aplicativo de celular para manejo da irrigação com base no clima por meio de redes neurais artificiais

The objective of this work was to develop a smartphone application (APP) for a weather-based irrigation scheduling using artificial neural networks (ANNs), as well as to validate it in a green corn (Zea mays) crop. An APP (IrriMobile) that uses ANNs based on temperature and relative humidity, or on temperature only, was developed to estimate the reference evapotranspiration (ETo). The APP and Bernardo’s methodology for irrigation scheduling, with the ETo estimated by the FAO-56 Penman-Monteith equation, were used to schedule the irrigation for a green corn crop. The performance of empirical equations to estimate ETo was also assessed. Several corn morphological and agronomic characteristics were evaluated. The APP was used in the experiment with temperature, relative humidity, and rainfall data. Its use was also simulated with temperature and rainfall data only. There was no difference for any of the green corn characteristics evaluated. ETo estimation through the APP showed a higher performance than that by the evaluated equations. The APP overestimates the irrigation requirements by 8 and 19% when using temperature and relative humidity, and temperature only, respectively. O objetivo deste trabalho foi desenvolver um aplicativo (APP) para manejo da irrigação com base no clima, por meio de redes neurais artificiais (ANNs), além de validá-lo em um cultivo de milho (Zea mays) verde. Desenvolveu-se um APP (IrriMobile) que utiliza ANNs com base em temperatura e umidade relativa, ou apenas em temperatura, para estimar a evapotranspiração de referência (ETo). O aplicativo e a metodologia de manejo da irrigação de Bernardo, com a ETo estimada pela equação FAO-56 Penman-Monteith, foram utilizados para manejar a irrigação na cultura do milho verde. Avaliou-se também o desempenho de equações empíricas para estimar a ETo. Avaliaram-se diversas características morfológicas e agronômicas do milho. O APP foi utilizado no experimento com dados de temperatura, umidade relativa e precipitação. Simulou-se, também, seu uso apenas com dados de temperatura e precipitação. Não houve diferença para nenhuma das características do milho avaliadas. A estimação de ETo pelo APP mostrou desempenho superior à das equações avaliadas. O aplicativo superestima os requisitos de irrigação em 8 e 19%, ao usar temperatura e umidade relativa, e apenas temperatura, respectivamente

UTILIZING SEVAP SOFTWARE TO ESTIMATE THE REFERENCE EVAPOTRANSPIRATION ON THE MINAS GERAIS STATE

Reliable estimates of reference evapotranspiration (ET0) are necessary to address different aspects related to the management of water and environmental resources. Due to the complexity of the equations, there is demand of using software to obtain ET0. There are several models for estimating ET0, each designed for different climatic conditions and which require review before being used in the new region. Therefore, this study aimed to test the SEVAP software with their different methodologies for estimate of ET0 in the Minas Gerais state. The methodologies tested were Hargreaves-Samani, Jensen-Haise, Linacre, Makkink and Priestley-Taylor. The meteorological data needed to perform this work were taken from Standard Climatological (1961-1990) of 50 localities of Minas Gerais, provided by the National Institute of Meteorology (Inmet). The method was taken as the standard Penman-Monteith-FAO56 and comparison of results was by the coefficient of determination (r²), the coefficients "a" and "b" of the linear regression equations, standard error of estimate (ESE), Willmott index of agreement (d), the Pearson correlation coefficient (r) and confidence coefficient (c). The SEVAP software showed simplicity in its use and accuracy in the estimate of ET0 in Minas Gerais state. The best methodologies for estimate of the ET0 in Minas Gerais were Pristley-Taylor, Hargreaves-Samani and Linacre. The Hargreaves-Samani method should be preferred and used only when has data of air temperature. The methodologies Jensen-Haise and Makkink should not be used to estimate ET0 in Minas Gerais stat

Droplets size in the phytosanitary control of potato / Tamanho da gota no controle fitossanitário de batata

The use of different spray nozzles with droplet size ranging from fine to coarse may compromise the application efficiency in potato crops. This study aimed to evaluate the production of potato in the northeast region of Mato Grosso do Sul by using different cultivars and droplet sizes in phytosanitary treatments. Potato is one of the crops that mostly depends on the application of phytosanitary products.  Potato cultivars were planted in the experimental area of the Universidade Federal de Mato Grosso do Sul, in the municipality of Chapadão do Sul. Plots consisted of three seedbeds (0.8 m x 1.4 m), and the plants were spaced at 0.35 m. The area of each experimental unit was 3.36 m2, to9taling 12 plants per unit. The experiment was carried out in subplots, in a randomized block design (2x3); the spray system had two droplets sizes (tips TT 110015 and TXA 8001VK, fine and coarse, respectively) in the plots and three potato cultivars (Yacon, Sminia, and Marcy) in the subplots, with four replications. The different droplets sizes interfere with the yield and morphology of potato tubers. The highest yield values are associated with fine droplets. Cultivar Sminia had longer tubers; however, Marcy showed thicker and wider tubers

Programa HS Cal para calibração da equação de Hargreaves-Samani

The objective of this work was to develop a software (HS Cal) to calibrate the Hargreaves-Samani equation for specific periods of the year, in global, seasonal, and monthly time scales, as well as to compare the performance of calibrated and non-calibrated equations. The software was developed in order to use raw data provided by Banco de Dados Meteorológicos para Ensino e Pesquisa (BDMEP). All calibrations outperformed the original Hargreaves-Samani equation, especially with the use of seasonal and monthly calibrations. The HS Cal software can easily calibrate the Hargreaves-Samani equation, allowing the identification of the best form of this equation for a given site.O objetivo deste trabalho foi desenvolver um programa (HS Cal) para calibrar a equação de Hargreaves-Samani para períodos específicos do ano, nas escalas global, sazonal e mensal, bem como comparar o desempenho das equações calibrada e não calibrada. O software foi desenvolvido para o uso de dados brutos fornecidos pelo Banco de Dados Meteorológicos para Ensino e Pesquisa (BDMEP). Todas as calibrações estudadas superaram a equação de Hargreaves-Samani original, especialmente com uso das calibrações sazonal e mensal. O programa HS Cal pode calibrar facilmente a equação de Hargreaves-Samani, o que possibilita a identificação da melhor forma desta equação para uma dada localidade

Irrigação de diferentes cultivares de rúcula no nordeste do Mato Grosso do Sul

The literature about the agronomic performance of vegetables irrigated in the Northeast of Mato Grosso do Sul State of Brazil is still scarce, and is based on empirical experiences of producers without scientific research references. Accordingly, it is indispensable to determine the performance of new materials, which show appropriate agronomic characteristics, in function of irrigation to increase the agricultural production. Therefore, the present study had the objective to evaluate the production of different cultivars of rocket submitted to different depths of irrigation and climatic seasons. The experiment was conducted in split plot scheme, having in the plots four irrigation depths (50, 75, 100 e 125% of crop evapotranspiration - ETc) and in the subplots, three cultivars of rocket (Apreciata Folha Larga - Feltrin, Cultivada - Feltrin e Folha Larga - Top Seed) and in the sub-subplots, two climatic season (dry and rainy), in the randomized block design with four replications. The following characteristics were evaluated: mass of fresh and dry matter plant-1, yield of fresh matter, leaf number, root depth and water use efficiency. Better performance of the rocket was observed in the dry season. The cultivar Folha Larga (Top Seed), independent of climate season, showed superior characteristics than other cultivars evaluated, the best yield of fresh matter was of 1,68 kg m-2, obtained in the dry season with irrigation depth of 125% ETc. The irrigation provided linear effect in the dry season and did not affect during the rainy season. The rocket Folha Larga (Top Seed) should be prefered by the producers of Northeast of Mato Grosso do Sul State of Brazil and irrigated with depth equivalent to of 50 and 125% ETc, in the rainy and dry season, respectively.A literatura sobre o desempenho agronômico de hortaliças irrigadas no nordeste sul-mato-grossense ainda é escassa e fundamentada em experiências empíricas de produtores, desprovidos de referências de resultados de pesquisas. Portanto, há necessidade de se determinar o desempenho de novos materiais, que apresentem adequadas características agronômicas, sob irrigação, para maximização da produção. Diante disso, objetivou-se avaliar a produção de diferentes cultivares de rúcula submetidas a diferentes lâminas de irrigação e épocas climáticas. O experimento foi conduzido em esquema de parcelas sub-subdivididas, tendo nas parcelas quatro lâminas de irrigação (50, 75, 100 e 125% da evapotranspiração da cultura), nas subparcelas três cultivares de rúcula (Apreciata Folha Larga - Feltrin, Cultivada - Feltrin e Folha Larga - Top Seed) e nas sub-subparcelas duas épocas climáticas (seca e chuvosa), no delineamento em blocos casualizados, com quatro repetições. Foram avaliadas as seguintes características: massas de matéria fresca e seca por planta, produtividade de massa fresca, número de folhas, comprimento das raízes e eficiência de uso da água. No geral, verificou-se melhor desempenho da rúcula na época seca. A cultivar Folha Larga (Top Seed), independentemente da época climática, apresentou características superiores às demais cultivares avaliadas, sendo que a maior produtividade de massa fresca foi de 1,68 kg m-2, obtida na época seca com lâmina de irrigação de 125% da ETc. A irrigação proporcionou efeito linear na estação seca e não conferiu efeito na estação chuvosa. A rúcula Folha Larga (Top Seed) deve ser preferida pelos produtores do nordeste de Mato Grosso do Sul e irrigada com reposição de 50 e 125% da ETc, nas épocas chuvosa e seca, respectivamente

Evapotranspiration for irrigated agriculture using orbital satellites

Acknowledging the importance of evapotranspiration as a mediating factor for efficient irrigation management and water balance, the objective of study is to compare the Simple Algorithm for Evapotranspiration Retrieving (SAFER) to the standard method proposed by FAO-56 for real evapotranspiration, as well as prove its value as an implement in irrigation management for the Brazilian Savanna. Data used refers to 2015’s harvest of seven center pivots, located in the municipality of São Desidério in western Bahia. For the SAFER algorithm, the images used were acquired by the Landsat-8 satellite during the entire maize crop cycle. The SAFER algorithm estimation demonstrates the spatial and temporal distribution of the evapotranspiration. A maximum evapotranspiration of 5.38 mm d-1 was observed during the crop’s reproductive stage. In relation to the standard method, SAFER showed a mean absolute error of 0.40 mm. Thus, concluding that the algorithm can be used to estimate the actual evapotranspiration crop as an alternative to the standard method proposed by FAO-56 for water resources management

Evapotranspiration mapping of commercial corn fields in Brazil using SAFER algorithm

SAFER (Simple Algorithm for Evapotranspiration Retrieving) is a relatively new algorithm applied successfully to estimate actual crop evapotranspiration (ET) at different spatial scales of different crops in Brazil. However, its use for monitoring irrigated crops is scarce and needs further investigation. This study assessed the performance of SAFER to estimate ET of irrigated corn in a Brazilian semiarid region. The study was conducted in São Desidério, Bahia State, Brazil, in corn-cropped areas in no-tillage systems and irrigated by central pivots. SAFER algorithm with original regression coefficients (a = 1.8 and b = –0.008) was initially tested during the growing seasons of 2014, 2015, and 2016. SAFER performed very poorly for estimating corn ET, with RMSD values greater than 1.18 mm d–1 for 12 fields analyzed and NSE values < 0 in most fields. To improve estimates, SAFER regression coefficients were calibrated (using 2014 and 2015 data) and validated with 2016 data, with the resulting coefficients a and b equal to 0.32 and –0.0013, respectively. SAFER performed well for ET estimation after calibration, with r2 and NSE values equal to 0.91 and RMSD = 0.469 mm d–1. SAFER also showed good performance (r2 = 0.86) after validation, with the lowest RMSD (0.58 mm d–1) values for the set of 14 center pivots in this growing season. The results support the use of calibrated SAFER algorithm as a tool for estimating water consumption in irrigated corn fields in semiarid conditions

Controlled water stress in agricultural crops in brazilian cerrado

Considering the scenarios with reduction of water availability, the need to increase water use efficiency and crop yield, the objective of this study was to evaluate the effect of reducing the evapotranspiration of the main irrigated crops on productivity. Data from the years 2005 to 2016 for carrot, garlic, potato, sugarcane, bean, maize, soybean, wheat, coffee and cotton crops grown in the Brazilian states of Bahia, Minas Gerais, São Paulo, Goiás, Distrito Federal and Mato Grosso were collected. The crops were irrigated by central-pivot irrigation and drip irrigation systems, and irrigation management was performed using IRRIGER® software. With the information on potential crop evapotranspiration (ETpc) and crop evapotranspiration (ETc), it was possible to obtain a reduction of ETpc (%) for all crops. For all scenarios, these data were confronted with crop productivity and regression models were fitted. It was concluded that the maximum reductions of ETpc (%) without affecting productivity are 5% for garlic and potato, 12% for maize, 13% for bean, 15% for wheat, 20% for soybean and cotton, 25% for sugarcane and 30% for coffee

INCREASE IN THE IRRIGATED AREA OF SUGARCANE AND ITS POTENTIAL IN THE BIOENERGETIC GENERATION OF BRAZIL

Sugarcane has a large capacity for producing electric energy using totally clean technology, from a renewable source, contributing to environmental preservation. The objective of this research was to evaluate the increase in biomass resulting from the implementation of irrigation in Brazilian sugarcane fields, estimate the potential for cogeneration, and calculate how much it will be possible to increase the Brazilian energy co-generated with sugarcane bagasse and the impact on the matrix Brazilian energy sector. The increase in irrigation in the rainfed areas of Brazilian sugarcane fields has substantial potential in increasing biomass for energy cogeneration. Considering a 15% increase in the production of cane fields in rainfed areas, conquered from the increase in irrigation, leads to an increase potential of 96.39 million tons of sugar cane and 26.80 million tons of biomass produced. In the energy matrix, the potential impact is 1.42 GWh of cogenerated energy, which corresponds to a 12.47% increase in cogeneration in the sugar-energy sector and 0.85% increase in Brazil's energy matrix. The expansion of the sugarcane irrigated area contributes to the increase in the production of bagasse and bioenergetic generation in Brazil.A cana-de-açúcar tem grande capacidade de produção de energia elétrica com tecnologia totalmente limpa, de fonte renovável, contribuindo com a preservação ambiental. O objetivo da presente pesquisa foi avaliar o incremento de biomassa advinda da implantação de irrigação nos canaviais brasileiros, estimar o potencial de cogeração, e calcular o quanto será possível aumentar a energia brasileira cogerada com bagaço de cana-de-açúcar e o impacto na matriz energética brasileira. O incremento de irrigação nas áreas de sequeiros dos canaviais brasileiros tem um potencial substancial no incremento de biomassa para a cogeração de energia. Considerando um aumento de 15% na produção dos canaviais das áreas de sequeiro, conquistados a partir do incremento de irrigação, ocasiona em um potencial de aumento de 96,39 milhões de toneladas de cana-de-açúcar e 26,80 milhões de toneladas de biomassa produzida. Na matriz energética, o impacto potencial é de 1,42 GWh de energia cogerada que corresponde a 12,47% de aumento de cogeração no setor sucroenergético e 0,85% de aumento na matriz energética do Brasil. A expansão da área irrigada de cana-de-açúcar contribui com o aumento da produção de bagaço e geração bioenergética do Brasil