Precision tools for irrigation management of tomato seedlings

A produção de mudas é um ponto crítico do sistema de produção de hortaliças. Devido a informações sobre o consumo de água pelas mudas, o planejamento da irrigação se torna ineficiente, fato que provoca perdas na qualidade das mudas. O objetivo do experimento foi testar o uso de hidrogel no substrato e determinar o manejo de irrigação adequado através de ferramentas de automatização do sistema de irrigação. O experimento foi conduzido em ambiente protegido na Universidade Federal de Viçosa. Foram produzidas mudas de tomate (Solanum lycopersicom) em bandejas de polietileno, preenchidas com substrato com e sem a presença de hidrogel. As mudas foram irrigadas com sistema de microaspersão, acionado a partir de um sistema automatizado. Os tratamentos de manejo de irrigação foram através da evapotranspiração da cultura (ETc), timer, 0.50 ETo e 1,00 ETo. Foram avaliados componentes de qualidade das mudas como altura, comprimento de raiz, diâmetro de colo, massa seca de raiz e parte aérea. O uso do hidrogel foi um diferencial para produção de mudas de tomate mais precoces, com maior altura final, maior diâmetro de colo, maior acúmulo de massa seca de parte aérea, maior área de projeção da copa e maior a taxa de crescimento relativo de parte aérea. Na presença do hidrogel o manejo 0.50 ETo favoreceu maiores plantas, com colo mais fino e menor massa seca de parte aérea

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

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

OPTIMIZING THE MONITORING OF NATURAL PHENOMENA THROUGH THE COUPLING OF ORBITAL MULTI-SENSORS

High frequency of images and high spatial resolution are necessary characteristics in studies with high temporal and spatial dynamics, which are difficult to find in a single orbital sensor. Therefore, the possibility of using multiple satellites to overcome this obstacle in monitoring is of fundamental importance. The aim of the study was to evaluate the multi-sensor coupling for the monitoring of phenomena that require a greater frequency of spatial detail and high-temporal observations by intercalibrating the reflectance images of the LISS III sensor, which is on board the satellite ResourceSat-II, and the MSI sensor onboard the Sentinel-2A, utilizing the Landsat-8 OLI sensor as standard. To perform the methodology, prior the intercalibration, it was necessary to convert the digital numbers of the bands into reflectance at the top of the atmosphere, so that intercalibration of data with simple linear regression could be subsequently performed. The results demonstrate that, with the intercalibrations of the reflectance images of the LISS III and MSI sensors, it is possible to couple the information of these sensors with those coming from OLI, enabling the increase of the frequency and availability of information in studies that require more observations, as in agricultural monitoring, natural disasters, and deforestation among others

Development and characterization of a fixed sprinkler with a rotating serrated plate

O objetivo do presente trabalho foi desenvolver placas defletoras estriadas com movimento rotativo e determinar o perfil de precipitação e as características hidráulicas de um aspersor fixo operando com as placas desenvolvidas. No desenvolvimento, foram mantidas as características de uma placa estriada fixa convencional, quanto ao número de estrias e diâmetro da placa, sendo as estrias feitas em helicóides, para possibilitar o movimento rotativo das placas. Foram desenvolvidos três tipos de placas: plana, côncava e convexa, as duas últimas apresentando uma inclinação de 10o. Constatou-se que a placa côncava foi a que apresentou os maiores valores de raio molhado e, consequentemente, os menores valores de intensidade de precipitação média; as diferenças mais acentuadas, entre a placa côncava e as demais, foram observadas nas menores alturas de instalação do difusor. De modo geral, o aumento na altura do difusor proporcionou reduções nos valores de intensidade de precipitação. Simulou-se, a partir dos perfis de precipitação, o coeficiente de uniformidade de Christiansen (CUC), para sistemas de irrigação do tipo pivô central e linear. Os valores de CUC simulados foram elevados, superando, na maioria dos casos estudados, os valores mínimos recomendados; os menores espaçamentos resultaram, de modo geral, nos maiores valores de CUC. Não foi evidenciada uma placa que se destacasse por apresentar os maiores valores de CUC.The objective of the present work was to develop serrated deflector plates with rotating movement and to determine the precipitation profile and hydraulics characteristics of one irrigation spray nozzles working with the deflector plates developed. The number of serrates and the diameter used were the same as for the conventional fixed plate. However, serrates were made in helicoydal form to ensure the rotating movement. Plane, concave and convex plates with a ten-degree angle were developed. The concave plate presented the highest wetted radius and consequently the lowest average precipitation rate, specially for lower height of sprinkler positioning. In general, the average precipitation rate decreased as the sprinkler height increased. The precipitation profiles for sprays with the plate were used to simulate the Christiansen Uniformity Coefficient (CUC) for center pivot and linear systems. The CUC increased as the sprinkler spacing decreased. All the CUC were higher than the minimum recommended. There was no difference between the CUC values for the different plates

Modeling Actual Evapotranspiration with MSI-Sentinel Images and Machine Learning Algorithms

The modernization of computational resources and application of artificial intelligence algorithms have led to advancements in studies regarding the evapotranspiration of crops by remote sensing. Therefore, this research proposed the application of machine learning algorithms to estimate the ETrF (Evapotranspiration Fraction) of sugar can crop using the METRIC (Mapping Evapotranspiration at High Resolution with Internalized Calibration) model with data from the Sentinel-2 satellites constellation. In order to achieve this goal, images from the MSI sensor (MultiSpectral Instrument) from the Sentinel-2 and the OLI (Operational Land Imager) and TIRS (Thermal Infrared Sensor) sensors from the Landsat-8 were acquired nearly at the same time between the years 2018 and 2020 for sugar cane crops. Images from OLI and TIR sensors were intended to calculate ETrF through METRIC (target variable), while for the MSI sensor images, the explanatory variables were extracted in two approaches, using 10 m (approach 1) and 20 m (approach 2) spatial resolution. The results showed that the algorithms were able to identify patterns in the MSI sensor data to predict the ETrF of the METRIC model. For approach 1, the best predictions were XgbLinear (R2 = 0.80; RMSE = 0.15) and XgbTree (R2 = 0.80; RMSE = 0.15). For approach 2, the algorithm that demonstrated superiority was the XgbLinear (R2 = 0.91; RMSE = 0.10), respectively. Thus, it became evident that machine learning algorithms, when applied to the MSI sensor, were able to estimate the ETrF in a simpler way than the one that involves energy balance with the thermal band used in the METRIC model

Development and production of fertigated coffee trees in the west region of Bahia, Brazil

This work was to evaluate the effects of different doses and fertigation parceling on the production and development of irrigated coffee drip in the Western Bahia region. He carried out the work on the farm White River Café, located in Barreiras - BA in coffee adults, approximately 3.5 years of age, Catuaí IAC 144. The experiment was conducted in a factorial 3 x 3, three levels of nitrogen and potassium fertilization (900/800, 600/500 and 300/250 kg ha-1 yr-1 N and K2O) in 3 monthly installments of fertigation (2, 4 and 8 times). The variables in the experiment were: productivity, growth, yield and sieve. The doses of 600/500 and 900/800 kg ha-1 yr-1 N / K2O, the highest yield of the coffee. The installments of fertigation at two and eight times per month were higher in productivity. A higher effect of splitting the fertigation, on the effect of N and K2O in the coffee development variables (crown diameter and plant height). There was no effect of dose and fertigation parceling on rating sieve of coffee beans.The aim in the present study was to evaluate the effects of different split fertigation and doses on the development and production of drip irrigated coffee in the western region of the state of Bahia, Brazil. The study was performed at the Café do Rio Branco Farm, in Barreiras, BA, Brazil, in adult coffee trees aged approximately 3.5 years from the variety Catuaí IAC 144. A 3 x 3 factorial design was adopted, with three levels of nitrogen and potassium fertilization (900/800, 600/500 and 300/250 kg ha-1 year-1 N and K2O) in three monthly split fertigation (two, four and eight times). Stem and crown growth, productivity, yield and sieve were evaluated. The doses of 600/500 and 900/800 kg ha-1 year-1 N/K2O and the splits in two and eight times provided the highest productivities of coffee. A higher split fertigation was observed on the effect of N and K2O doses in coffee development variables (crown diameter and plant height). There was no effect of split fertigation and doses in the classification by sieves of coffee beans

ANÁLISE TÉCNICA DOS SISTEMAS DE IRRIGAÇÃO DO CAFEEIRO (Coffea arabica L.) NA REGIÃO OESTE DA BAHIA

This study aimed to evaluate the uniformity of 27 irrigation systems with 7 as drip and 20 as central pivot, located in 12properties distributed in three counties of western Bahia. Of the 20 central pivot irrigation systems evaluated, 11 were equipped withsprinklers such as “Low Energy Precision Application” (LEPA), five with alternative sprinklers and four conventional sprinklers. Wedetermined the Christiansen Uniformity Coefficient (CUC) and the coefficient uniformity of distribution (CUD) of each system. Of thecentral pivots evaluated, only two (10%) had CUC values below 80%, which is considered unsuitable. Of the seven drip irrigationsystems evaluated, only one showed an unacceptable CUD value. The average value of CUD found during the evaluations, for thecentral pivot irrigation system with sprinklers equipped with LEPA was higher than the value given by drip. The central pivots withlocalized application (LEPA and alternative) had higher values of uniformity than the conventional central pivots.No presente trabalho, objetivou-se a avaliação da uniformidade de aplicação de 27 sistemas de irrigação, sendo sete porgotejamento e 20 por pivô central, localizados em 12 propriedades de cafeicultores distribuídas em três municípios da região oeste daBahia. Dos 20 sistemas de irrigação por pivô central avaliados, 11 foram pivôs equipados com emissores do tipo “Low EnergyPrecision Application” (LEPA), cinco com emissores alternativos e quatro eram pivôs centrais convencionais. Determinaram-se oCoeficiente de Uniformidade de Christiansen (CUC) e o Coeficiente de Uniformidade de Distribuição (CUD) de cada sistema. Dospivôs centrais avaliados, apenas dois (10%) apresentaram valores de CUC abaixo de 80%, considerados inadequados. Dos setesistemas de irrigação localizada por gotejamento avaliados, apenas um exibiu valor de CUD considerado inaceitável. O valor médio deCUD encontrado, durante as avaliações, no sistema de irrigação por pivô central equipado com emissores LEPA foi superior ao valorapresentado pelo sistema de gotejamento. Os pivôs centrais de aplicação localizada (LEPA e alternativos) apresentaram valores deuniformidade superiores aos dos pivôs centrais convencionai

Efeitos da irrigação na produção e no desenvolvimento do cafeeiro na região oeste da Bahia

Irrigation redesigned the distribution of the cultivation of coffee in Brazil, and upon this, new studies in water consumption and in its relationships with production and growth in coffee became necessary. The objective of this work was to evaluate the effects of irrigation on the production and growth in coffee irrigated by drip irrigation, in the West region of Bahia. For this, a trial was carried out in the farm Café do Rio Branco, located in Barreiras – BA. The experiment was caried out with adult plants of coffee of the variety Catuaí Vermelho, approximately 3.5 years old and set up in a randomized block design, with five treatments and four replicates. The treatments corresponded to 75, 85, 100, 125 and 150% of the irrigation depth and were calculated by the Irriplus software. It was evaluated the productivity, water use efficiency (WUE), vegetative development, sieve classification, as well as the yield and maturation of fruits. A significant effect of the irrigation depth in yield, WUE and maturation of fruits (green and cherry) was observed at the end of four consecutive harvests. The estimated maximum productivity (60 sc ha-1), was obtained with 129% of the irrigation depth and a maximum WUE (5.7 kg mm-1) obtained with 75%. As to maturation, they were significant only for green (19.7%) and cherry fruits (67.5) with the irrigation depths of 119 and 121%, respectively. There was no significant effect of the different irrigation depths in the vegetative development, sieve classification and yield of fruits.A irrigação redesenhou a distribuição das lavouras cafeeiras no Brasil e com isso tornaram-se necessários novos estudos de consumo de água e suas relações com a produção e crescimento do cafeeiro. Este trabalho foi desenvolvido com o objetivo de avaliar os efeitos da irrigação sobre a produção e o desenvolvimento do cafeeiro irrigado por gotejamento na região Oeste da Bahia. Para isso foi implantado um experimento na fazenda Café do Rio Branco, localizada em Barreiras – BA, em cafeeiros adultos, aproximadamente 3,5 anos de idade, da variedade Catuaí Vermelho IAC 144. O experimento foi montado no delineamento em blocos casualizados, composto de 5 tratamentos, correspondentes à 75, 85, 100, 125 e 150% da lâmina de irrigação calculada pelo software Irriplus. Observou-se, ao final de quatro safras, efeito significativo da lâmina de irrigação na produtividade do cafeeiro. A produtividade máxima estimada (60 sc ha-1) foi obtida com a lâmina correspondente a 122% da lâmina de irrigação. Não houve efeito das diferentes lâminas de irrigação no desenvolvimento vegetativo, na classificação por peneira, no rendimento e na maturação dos frutos do cafeeiro

Comparação entre métodos simplificados de estimativa da evapotranspiração de referência (ETo) para regiões produtoras de café brasileiras

This work aimed to estimate and compare two simplified methods to estimate the reference evapotranspiration – Eto, Hargreaves-Samani (HS) and FAO-Blaney-Criddle, (BC) to the Penman-Monteith-FAO (PM) method. The results of the estimates were obtained on the basis of climatic data available at each location under study, using Irriplus software. The cities of interest for the study were selected according to the representativeness of the characteristics of the region between the main brazilian producing centers of coffee: Cerrado, East, South and Zona da Mata of Minas Gerais state, west and southwest of Bahia state, and the cities chosen were Araguari, Patrocínio, Caratinga, Lavras, Varginha, Viçosa, in Minas Gerais state, and Vitoria da Conquista and Barreiras, Bahia state. In all locations, HS equation best fit to the equation of PM, this being recommended for irrigation management in conditions of limited availability of climate data. O presente trabalho teve como objetivos estimar e comparar a evapotranspiração de referência - ETo de dois métodos simplificados, Hargreaves-Samani (HS) e Blaney-Criddle-FAO (BC), com o método Penman-Monteith-FAO (PM). Os resultados das estimativas foram obtidos em função dos dados climáticos disponíveis de cada localidade em estudo, com o auxílio do aplicativo Irriplus. As cidades de interesse para o estudo foram selecionadas de acordo com a representatividade das características da região entre os principais centros produtores brasileiros de café: Cerrado, Leste, Sul e Zona da Mata de Minas Gerais, Oeste e Sudoeste da Bahia, sendo as cidades escolhidas: Araguari, Patrocínio, Caratinga, Lavras, Varginha e Viçosa, em Minas Gerais; e Vitória da Conquista e Barreiras, na Bahia. Em todas as localidades, a equação de HS se ajustou melhor à equação de PM, sendo esta a recomendável para o manejo da irrigação em condições limitadas de disponibilidade de dados climáticos.