A portable dual-camera video system was used to evaluate the potential for using total projected green cover as an indirect measure of weed infestations in a wheat crop during early growth stages. The video system would have applications in mapping weed infestations to assist precision farming operations. <p>The two cameras provided a real-time composite image of reflected light measured in red (640 nm), and near-infrared (860 nm) wavelengths. A simple ratio of reflected light intensity in each wavelength was used to isolate the growing plants from the background. Software was developed to automatically adjust for varying ambient light conditions and calculate the percentage of the image occupied by growing plants. Total green cover was measured at randomly selected sites prior to direct seeding wheat and at four growth stages following wheat emergence. The portion of green cover observed was compared to crop and weed dry matter at each location. Weed infestations at each location were estimated by measuring the total green cover and subtracting the projected green cover due to the crop alone. A minimum weed dry matter of 20 g/m2 and 30 g/m2 could be detected by the video system at the 3-leaf and 5-leaf growth stages, respectively. Weed dry matter less than 20 g/m2 could not be detected reliably due to the variability of the wheat crop. Detection of weeds within the crop beyond the 5-leaf stage using this method was difficult due to crop canopy closure.

Support for sustainable agriculture by farmers and consumers is increasing as environmental and socio-economic issues rise due to more intensive farm practices. Site-specific crop management is an important component of sutainable agriculture, within which remote sensing can play an integral role. Field and image data were acquired over a farm in Saskatchewan as part of a national research project to demonstrate the advantages of site-specific agriculture for farmers. This research involved the estimation of crop biophysical parameters from airborne hyperspectral imagery using Spectral Mixture Analysis (SMA), a relatively new sub-pixel scale image processing method that derives the fraction of sunlit canopy, soil and shadow that is contributing to a pixel's relectance. SMA of three crop types (peas, wheat and canola) performed slightly better than conventional vegetation indices in predicting leaf area index (LAI) and biomass using Probe-1 imagery acquired early in the growing season. Other potential advantages for SMA were also indentified, and it was conclude that future research is warranted to assess the full potential of SMA in a multi-temporal sense throughout the growing season. / xiv, 194 leaves : ill. (some col.) ; 29 cm.

The primary objective of this research project is to develop a system for precision spraying of herbicides in a corn field. Ultimately, such a system would permit real-time image collection, processing, weed identification, mapping of weed density and sprayer control using a tractor-mounted digital camera and on-board computer. The initial hypotheses underlying this project were (1) that it is possible to train an artificial neural network (ANN) to distinguish weeds from a crop species (corn in this study); (2) that it is possible to differentiate between weed species; and (3) that precision spraying can significantly reduce the quantity of herbicide needed to protect crop yields, thus reducing both the costs and environmental impacts of such applications. Thus, development of an ANN for this purpose was the main focus of the research project. / Since the success of ANN development is primarily dependent on the type of information that it is provided, much of the work involved investigation of different approaches to extracting information from the digital images of field sections and individual objects (weeds or corn plants), as well as analysis of the type of information extracted. The applicability of a given image processing method was evaluated in terms of the image recognition accuracy, as well as the computer time and memory requirements for processing and obtaining ANN output, since speed is of the essence in real-time applications. The greenness method based on a pixel-by-pixel analysis of red-green-blue intensity value of the original images was the most successful and was used in further work. / As it turned out, ANN development for this purpose was difficult. While the success rate for recognition of corn plants was high (80% or greater), the success rate for recognition of weeds tended to be low. Improvements in weed recognition were met with decreases in the success rate of corn recognition. Differentiation between weed species was less than desirable. Differentiation between corn and a given weed species was also not as good, particularly when the weed species was similar in appearance to the young corn plant. / Therefore, another strategy was developed to recognize weeds in the field by taking images between the corn rows. Previously, the images were taken randomly in the field. The images were processed to obtain percent greenness in each image and this information was used to create weed coverage and weed patchiness maps. Based on these maps, herbicide spraying was decided and spraying amounts were determined. In terms of real-time, it was possible to process the equivalent of one metre of row per second. Although this is slow compared to tractor speed in the field, the computer was not operating under dedicated conditions as one would require for the real-time application. Thus, the results were considered encouraging. / The final stage of the work involved an evaluation of the potential herbicide savings from a precision spraying system. This was done by using the weed coverage and weed patchiness maps as inputs to a simulated fuzzy logic controller, and integrating the output of the controller over the field area corresponding to the input images. The simulations with different fuzzy rules and membership functions indicated that the precision spraying approach could reduce the amount of herbicide needed for weed control in a corn field by up to 15%.

In the recent past precision farming has become increasingly popular amongfarmers. However, little has been done to study the business aspect of precision farming,with most research focusing on the production side. This purpose of this thesis is tostudy the feasibility of successfully opening and operating a precision farming firm inKentucky. To determine the feasibility of such a venture a computer model was createdand a producer survey was designed and distributed to farmers in Western and CentralKentucky.The purpose of the computer model was to determine the factors that wouldinfluence the successful operation of a precision farming firm including number of acresserviced per year, pricing of services, the cost of capital to borrow money, and manyother factors. A break-even analysis was performed to determine what kind of annualincreases in business would be required, what price range services should be in, and atwhat interest rate money could be borrowed and a simulated precision farming firm couldstill operate successfully.The producer survey was mailed to 336 farmers in Western and Central Kentuckybecause of their geographical locations and the type of crops that are grown there. Thesurvey response rate was 20 percent and of the 66 surveys that were returned 59 wereappropriate and useful for research. After compiling the results of the surveys,regressions were run to determine any correlation between dependent and independentvariables that affect the adoption rate of precision farming techniques. The results foundthat a negative correlation exists between age adoption rates of precision farming and thata positive correlation exists between farm size and adoption rates of precision farming.After conducting the research, it is believed that given the right economicconditions and management a precision farming firm is very capable of thriving inKentucky. However, the workforce must be very motivated and capable of constantlyrecruiting new clients to adopt precision farming.

Thesis (M.Sc.)--University of Manitoba, 2006. / A thesis submitted to the Faculty of Graduate Studies in partial fulfillment of the requirements for the degree of Master of Science, Department of Soil Science. Includes bibliographical references.

Made available in DSpace on 2014-06-11T19:23:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-08-09Bitstream added on 2014-06-13T18:09:46Z : No. of bitstreams: 1 000739148.pdf: 3421966 bytes, checksum: 9a708a07f344ae3523704cac58e8e872 (MD5) / O mapeamento da distribuição espacial dos atributos físicos e químicos do solo, relacionados à produtividade agrícola, permite identificar zonas de manejo específico para as culturas, garantindo maior produtividade com menor custo de produção. Assim, o objetivo deste trabalho foi discriminar a variabilidade espacial dos atributos físicos e químicos do solo relacionada à produtividade da cultura do café, identificando e mapeando zonas de manejo específico para a cultura, utilizando a suscetibilidade magnética (SM), espessura do solo e atributos da planta. O trabalho foi realizado no município de Matão, estado de São Paulo, na Fazenda Cambuhy Agrícola Ltda, onde o solo é classificado como Argissolo Vermelho- Amarelo Distrófico. A área de estudo, de aproximadamente 39 hectares, foi escolhida mediante representatividade fisiográfica regional, onde nos últimos 25 anos foi ocupada exclusivamente por café, cuja espécie estudada foi Coffea arabica, cultivar Catuaí Amarelo IAC 62 com 7 anos de idade e espaçamento de plantio 3,5 x 0,50 m, fertiirigado por gotejamento. Para estabelecer os pontos de coleta, foi gerada uma malha amostral sob a área, com intervalos regulares de 45 m, perfazendo um total de 173 pontos. Em cada ponto, amostras de solo foram coletadas nas profundidades de 0,0 - 0,20 m e 0,60 – 0,80 m, para a avaliação dos atributos físicos, químicos, granulométricos e (SM). A unidade amostral de cada ponto foi composta por nove plantas, cuja produtividade, porcentagens de grãos retidos nas peneiras 14, 16 e 17, e tipo de café foram avaliados. Os atributos da planta, tais como teor de macro e micronutrientes da folha, altura da planta, diâmetro da copa e comprimento do ramo plagiotrópico também foram avaliados. A área de estudo foi representativamente amostrada para a avaliação da espessura do solo, o que permitiu a divisão da área em dois ambientes... / Spatial distribution mapping of physical and chemical soil attributes, related to the agricultural productivity, allowed the identification of specific management zones for crops, ensuring greater productivity with lower production costs. The objective of this study was to evaluate the spatial variability of physical and chemical soil attributes related to coffee productivity, identifying and mapping specific culture management areas, using magnetic susceptibility (MS), soil thickness and plant attributes. The study was conducted in Matão, municipality of São Paulo state, at Fazenda Cambuhy Agrícola Ltda, where the soil is classified as dystrophic Ultisol. The area studied, of about 39 hectares, selected by physiographic regional representation, was occupied exclusively by coffee in the last 25 years. The variety studied was Coffea arabica, Catuai Yellow IAC 62 cultivar, 7 years old and planting spacing 3,5 x 0,50 m. To establish the point’s samplings, it was generated a grid with regular intervals of 45 m, totalizing 173 points. In each point, soil samples were collected at 0,0 - 0,20 m and 0,60 - 0,80 m depth to evaluate the physical, chemical and granulometric attributes and magnetic susceptibility (MS). The sampling unit of each point was compounded by nine plants, whose productivity, percentage of grains in the sieves 14, 16 and 17, and coffee type, were evaluated. The plants attributes as content of macro and micronutrients in the leaf, plant height, canopy diameter and reproductive branches length were also evaluated. The area studied was representatively sampled for evaluation of the soil thickness, which allowed the division of the area in two different environments. The statistical and geostatistical analysis showed that most of the attributes studied presented spatial dependence. The analysis of MS, soil fertility, nutritional status of the plant and coffee type was efficient ...

Orientador: Carlos Eduardo Angeli Furlani / Coorientador: Cristiano Zerbato / Banca: Marcelo Boamorte Ravelli / Banca: Carlos Alessandro Chioderoli / Resumo: Há uma necessidade do uso de ferramentas para estimativa do potencial produtivo durante o desenvolvimento da cultura do milho. Assim, o auxílio por meio sensores ópticos ativos para a geração de índices de vegetação, pode fornecer informações significativas para o conhecimento do comportamento e relação temporal destes índices com parâmetros produtivos das culturas agrícolas. Objetivou-se avaliar o comportamento temporal do NDVI e a sua relação com a produtividade da cultura do milho com o intuito de gerar modelos de predição de produtividade nas populações de plantas (55, 60 e 65 mil plantas ha-1) em espaçamento de semeadura reduzida e em linhas duplas. Foi utilizado fatorial 2 x 3 com 4 repetições, perfazendo 24 parcelas experimentais de 10 m2 de área útil em blocos casualizados, realizando a leitura do NDVI em 5 épocas (30, 45, 60, 75 e 90 dias após a emergência das plantas - DAE). O espaçamento em linhas duplas aos 90 e 30 DAE para as populações de 55 e 60 mil plantas ha-1, respectivamente permitiram gerar modelos para a predição de produtividade com base no NDVI do milho, enquanto que para a população de 65 mil plantas ha-1 aos 45 e 60 DAE não houve ajuste do modelo de predição de produtividade por valores próximos de NDVI para produtividades diferentes. No espaçamento reduzido a geração de modelos para a predição de produtividade foi possível nas populações de 55 e 60 mil plantas ha-1 respectivamente aos 90 e 30 DAE. / Abstract: There is a need for the use of tools to estimate productive potential during corn crop development. Thus, the assistence by means of active optical sensors for the generating of vegetation indexes can provide significant information for the knowledge of the behavior and temporal relation of this index with productive parameters of the agricultural crops. It was aimed to evaluate the temporal behavior of NDVI and its relation with productivity of corn in order to generate productivity prediction models in plant populations (55, 60 and 65 thousand plants ha- 1 ) in spacing of conventional seeding and twin rows. A factorial 2 x 3 was utilized with four replicates, with a total of 24 experimental plots of 10 m2 in randomized blocks, performing reading NDVI at 5 seasons (30, 45, 60, 75 and 90 days after emergence of the plants DAE). The spacing in twin rows at 90 and 30 DAE for populations of 55 and 60 thousand plants ha-1, respectively, allowed to generate models for the prediction of productivity based on corn NDVI, while the population of 65 thousand ha-1 plants at 45 and 60 DAE there was no adjustment by the prediction model of productivity by values close to NDVI for different productivities. In the conventional spacing generating models for the prediction of productivity was possible in the populations of 55 and 60 thousand plants ha-1 respectively at 90 and 30 DAE. / Mestre

Orientador: José Eduardo Pitelli Turco / Coorientador: Luís Cesar Dias Drumond / Banca: José Luiz Rodrigues Torres / Banca: Nivaldo Carleto / Banca: David Luciano Rosalen / Banca: Antonio Carlos Barreto / Resumo: A agricultura de precisão vem sendo utilizada para melhorar os níveis de produtividade e reduzir os impactos ambientais. Sendo um processo que leva em conta a coleta e análise de dados, bem como a gestão da variabilidade espacial e temporal (manejo localizado), no intuito de implementarmos respostas em escala e tempo adequados, objetivou-se neste trabalho corroborar no sentido de aumentar a melhoria da eficiência de utilização da água na gestão da irrigação, por meio de um controlador (hardware e software) automático, com tecnologia de comunicação sem fio. A proposta foi desenvolver um equipamento de precisão para possibilitar que a irrigação fosse estabelecida a partir da aplicação da água em turnos de rega e lâminas variáveis, ao invés de critérios fixos de forma arbitrária, caracterizando o controlador como um sistema automático de irrigação com aplicação em taxa variável. A eficiência do equipamento foi validada em um sistema de irrigação por aspersão para pastagem, embora possa ser utilizado para controlar a irrigação de qualquer cultura, bastando para isso conhecermos o tipo de sistema de irrigação, o(s) coeficiente(s) da cultura (Kc) e os limites de capacidade de campo e de ponto de murcha permanente do solo (análise da retenção da água no solo), no intuito de estabelecermos um parâmetro de disponibilidade hídrica a ser utilizada pela cultura. Com os resultados concluiu-se que o controlador proposto mostrou-se original e eficiente no controle da irrigação para enlaces ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The precision agriculture has been used to improve productivity levels and reduce environmental impacts. As a process that takes into account the collection and analysis of data, as well as the management of spatial and temporal variability (localized management), in order to implement responses on an adequate scale and time, this study aimed to corroborate in order to increase the improvement of the efficiency of water use in irrigation management, by means of an automatic controller (hardware and software) with wireless communication technology. The proposal was to create a precision equipment to enable that the irrigation was established from the application of water in watering shifts and variable levels, instead of arbitrarily fixed criteria, characterizing the controller as an automatic irrigation system with the application at a variable rate. The efficiency of the equipment was validated in a pasture irrigation system, although it can be used to control the irrigation of any crop, just by knowing the type of irrigation system, the crop coefficient(s) (Kc) and the limits of field capacity and the soil permanent wilting point (analysis of water retention in the soil), in order to establish a parameter of water availability to be used by the crop. With the results, we concluded that the proposed controller proved to be original and efficient in irrigation control for links up to 212 meters among its communication modules. / Doutor

O Brasil tem posição de destaque na produção agrícola mundial. A adoção de tecnologias que permitam preservar os recursos naturais e produzir alimento em quantidade e com qualidade é importante para o desenvolvimento do agronegócio. Dentre as tecnologias, destaca-se a Agricultura de Precisão – AP. O objetivo deste trabalho foi investigar a adoção da AP e os fatores relacionados a tal decisão dos produtores rurais no estado do Rio Grande do Sul. Com este propósito, foram coletados dados através do envio de questionário para produtores rurais usuários da AP. A análise descritiva dos dados permitiu caracterizar os adotantes e a adoção das ferramentas de AP entre os produtores rurais, enquanto a análise fatorial seguida de regressão linear múltipla foram empregadas para verificar a percepção dos adotantes quanto aos atributos tecnológicos da AP. Os resultados mostram o crescimento da adoção da AP e que o tempo médio de adoção é de 4,3 anos. Os adotantes de AP possuem grau de escolaridade elevado, utilizam diversas fontes de informação, têm a renda predominantemente agrícola e cultivam grandes áreas de terra. As ferramentas de AP mais adotadas no cultivo de grãos (soja, milho e trigo) são a amostra de solo georreferenciada (ASG), a aplicação em taxa variada de corretivos e fertilizantes (ATV) e o sistema de direcionamento de barra de luz (BLZ). Constatou-se que a adoção da AP é altamente dependente da terceirização de serviços de AP. O número de ferramentas de AP adotadas está positivamente associado ao tamanho da área cultivada, anos de experiência com AP, renda agrícola e investimento em AP. Os atributos tecnológicos da AP – vantagem relativa, visibilidade, compatibilidade e experimentação – determinam 48% da satisfação do adotante de AP, sendo o fator de maior potencial explicativo a vantagem relativa da tecnologia. Evidenciado o crescimento recente da adoção da AP entre os produtores rurais no Brasil, emergem oportunidades de pesquisas que venham a contribuir com a indústria e instituições de fomento na difusão da AP. / Brazil plays an important role in world agricultural production. The adoption of technologies which allow the increase of food production with improving quality in addition to natural resources conservation is important for agribusiness development, and Precision Agriculture – PA stands out as an option to aid the achievement of these goals. The aim of this work was to investigate the Adoption of PA, as well as the factors related to its adoption by farmers in Rio Grande do Sul, Brazil. With this purpose, an online survey was sent to PA adopters. Descriptive analysis allowed the characterization of the PA adopters and the identification of the most adopted PA tools, while factor analysis followed by multiple linear regression were used in order to verify users’ perception regarding PA technology attributes. The results show a PA adoption growth and an average time of adoption of 4.3 years. PA adopters have a high level of formal education, use several sources of information, have a predominantly agricultural income and cultivate large areas. The most adopted PA tools used for growing soybeans, maize and wheat are grid soil sampling, variable rate application and lightbar guidance. It was noted that PA adoption is highly dependent on PA services. The number of PA tools adopted is positive associated with the size of cultivated areas, years of PA use, agricultural income and investments in PA. PA technology attributes – relative advantage, observability, compatibility and trialability – determine 48% of the PA adopters’ satisfaction, being relative advantage of technology the factor of greatest explicative potential. The recent growth of PA adoption by Brazilian farmers shows emerging opportunities for research development which may contribute with industry and government institutions on PF diffusion.

OLIVEIRA, Antônio Dimas Simão de. Avaliação do sensor de umidade TOPDEA no manejo da irrigação. 2008. 71 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia Agrícola, Progarma de Pós-Graduação em Engenharia de Agrícola, Fortaleza-CE, 2008. / Submitted by demia Maia (demiamlm@gmail.com) on 2016-06-14T12:51:05Z No. of bitstreams: 1 2008_dis_adsoliveira.pdf: 13748562 bytes, checksum: 57833bde003cd50858fd12de77a6e763 (MD5) / Approved for entry into archive by demia Maia (demiamlm@gmail.com) on 2016-06-14T12:51:34Z (GMT) No. of bitstreams: 1 2008_dis_adsoliveira.pdf: 13748562 bytes, checksum: 57833bde003cd50858fd12de77a6e763 (MD5) / Made available in DSpace on 2016-06-14T12:51:34Z (GMT). No. of bitstreams: 1 2008_dis_adsoliveira.pdf: 13748562 bytes, checksum: 57833bde003cd50858fd12de77a6e763 (MD5) Previous issue date: 2008 / The scientific community, in recent years, has intensified studies to measure the impacts to the environment caused by pollution, mainly the adverse effects to air and water. The fact that less than 1% of the global water resources is comprised of drinking water and available at the surface of the earth makes it a commodity of conflict. According to the FAO by 2030 to meet the demand caused by the growth of the world population a 14% increase in available drinking water will be required for irrigation. To meet that expectation, the classical questions of when and how much to irrigate needs to be assessed. Thus, professionals in the fields of engineering have especially focused on practices to increase the efficiency of irrigation. This study aimed at evaluating a moisture sensor, a capacitive type, called TOPDEA, in irrigation management. The soil moisture is the most basic index to quantify water in a soil, expressed in units of mass or volume. The monitoring of the soil moisture is one of the most important factors for proper irrigation management. The experiment was carried out in the Irrigated Perimeter of the Lower Acaraú Basin – Ceará, in two different fields: The first one cultivated with bananas where preliminary tests were conducted to evaluate the sensor calibration, and the second one with watermelon for irrigation scheduling. The sensors were calibrated by means of the regression analysis between moisture and frequency output of the sensors from saturation to approximately 4% moisture content. The calibration was validated by comparing resulting irrigation timing produced by scheduling the irrigation with sensors and with a weather station. The number of sensors per hactare was analyzed by analyzing the timing of irrigation for each additional sensor in the field. The effect of the placement of the sensors (position in relation to the dripper and plant) was evaluated. The calibration equation for the sensor was found to be potential ( 1778371018 −2,3894213 q = f ). The highest readings occurred with frequency of the sensor installed 25.3 cm from the emitter, while the lowest occurred at 19.85 cm. The largest irrigation time was found when two sensors were used for each hectare, while the lowest was found using five sensors per hectare. The total irrigation depth with the scheduling conducted with capacitive sensors was 377.96 mm, which resulted in a total volume of 532.17 m³ of water in the entire cycle of watermelon. Crop yield was 36.0 t ha-1 and the water efficiency of 0.068 kg L-1. Water productivity was 16.18 to 26.47% higher compared to the irrigation management commonly practiced in the irrigation district for watermelon. Given the characteristic of soil physics with low water storage capacity, the daily irrigation requirement must be fractioned into several irrigation pulses starting early morning and the application of the total daily requirement in one irrigation event during the night (practice commonly conduction in the district to reduce the electricity bill) should be avoided leading to inefficient of irrigation. The distance between the sensor and the emitter has direct influence on its output. The TOPDEA sensor has proven to be accurate and efficient in the management of irrigation. / A comunidade científica mundial, nos últimos anos, tem intensificado os estudos para mensurar os impactos causados ao ambiente pela poluição, principalmente os efeitos adversos ao ar e água. O fato de menos de 1% da água ser potável e estar disponível à superfície da terra torna a mesma um bem de conflito. Segundo a FAO até 2030 será necessário um incremento de 14% da água potável, na irrigação, a fim de suprir a demanda provocada pelo crescimento da população mundial. Um dos problemas clássicos, no manejo da irrigação, é determinar quando e quanto irrigar e no intuito de sanar tal problema, profissionais da área de engenharia buscam cada vez mais, através de pesquisas, aumentar a eficiência de irrigação. O presente trabalho teve como objetivo avaliar um sensor de umidade, do tipo capacitivo, denominado TOPDEA, no manejo da irrigação. A umidade do solo é o indicador mais básico da água em uma amostra de solo. O monitoramento da umidade do solo é um dos fatores mais importantes para manejo correto da irrigação, contribuindo de forma direta para a determinação de quando e quanto irrigar. O experimento foi realizado no Perímetro Irrigado do Baixo Acaraú – Ceará, em duas áreas distintas: A primeira com banana para ensaios preliminares de campo e avaliação da equação de calibração do sensor e a segunda com melancia para o manejo da irrigação propriamente dito. Os sensores foram calibrados através de análise de regressão entre umidade e freqüência produzida pelos mesmos, partindo do ponto de saturação até aproximadamente 4% de umidade. A avaliação da equação de calibração ocorreu através da comparação entre os dados dos sensores e os dados da estação meteorológica, para tempo de irrigação. O número de sensores por hectare foi analisado pela comparação entre o número de sensores por hectare e seus respectivos tempos de irrigação. O efeito geométrico da distância de instalação dos sensores, em relação aos emissores, foi analisado através do teste de médias das leituras com as respectivas distâncias de instalação. A equação de calibração para a umidade foi do tipo potencial ( 1778371018 −2,3894213 q = f ). As maiores leituras de frequência ocorreram com o sensor instalado a 25,3 cm do emissor, enquanto que as menores ocorreram a 19,85 cm. Os maiores tempos de funcionamento do sistema de irrigação ocorreram utilizando-se dois sensores por hectares, enquanto os menores tempos ocorreram utilizando-se cinco sensores por hectare. A lâmina total de irrigação utilizando-se sensores foi de 377,96 mm, o que resultou em um volume total de água igual a 532,17 m³ para todo o ciclo da cultura. A produtividade foi de 36,0 t ha-1 e a eficiência do uso da água foi de 0,068 kg L-1. A produtividade da água foi de 16,18 a 26,47% superior àquela obtida com o manejo da irrigação local praticado no perímetro para a cultura da melancia. Dada a característica de armazenamento do solo, deve-se fracionar a irrigação com a primeira ocorrendo nas primeiras horas da manhã. Assim, a irrigação noturna de uma grande lâmina (prática comum do Perímetro) conduz à ineficiência da irrigação. A distância entre o sensor e o emissor tem influência direta da resposta do mesmo. O sensor TOPDEA mostrou-se preciso e eficiente no manejo da irrigação.