ABSTRACT This study aimed to evaluate the effect of water supply and sowing time on yield and yield components of two corn hybrids grown during offseason in the region of Dourados-MS, Brazil. The experimental design was randomized blocks in sub-divided plots, with four replications. In the main plot, two sowing dates were defined (2013 crop year: February 27 and March 27; and 2014 crop year: March 18 and April 5). In subplots, irrigation management systems were defined (irrigated and rainfed). Hybrids AS 1555 and AS 1590 were grown in the sub-plots. The parameters evaluated were plant height, ear insertion height, stem diameter, ear length and diameter, 100-grain weight, and grain yield. Regardless of irrigation and hybrid used, sowing time significantly affected corn yield, which responded to climate changes throughout crop cycle. Water supply increased corn yield, with the highest value being of 9338 kg ha-1 (156 bags ha-1) and obtained when irrigated AS 1555 hybrid was sown on February 27, 2013.

ABSTRACT Increasing population and demand for animal-derived products has raised the need for improved efficiency in managing and controlling animal production. Given this context, the project aimed to develop a device that aids decision-making in animal production. A hardware system was designed for instant measurement of thermal well-being levels, light intensity, and air gas concentration. This hardware integrated DHT11 sensors, an LDR photoresistor, and an MQ-135 sensor. To validate the system, a 30-day experimental study was conducted in an industrial pig farming setting. The collected data was sent to the Thingspeak server using the HTTP protocol. Data management, filtering, and organization were optimized using developed treatment algorithms. The system presented information on air humidity, temperature, ammonia concentration, CO2 levels, luminosity, and enthalpy through interactive images on a dashboard. In the case of a risk situation, the system automatically notified users with an "ALERT" message, facilitating prompt and efficient management response, and minimizing losses. The sensor calibration process yielded a high coefficient of determination (r2 = 0.98). Thus, the developed IoT device represents a viable solution, providing precise environmental conditions to support producers and enhance their efficiency and sustainability.

RESUMO Conhecer a umidade de solo disponível para as plantas é preponderante para o manejo adequado do uso da água nas propriedades agrícolas, sendo os métodos automatizados os mais precisos. Entretanto, os custos de aquisição são elevados e a maioria dos controladores de irrigação ainda trabalha com tempos pré-definidos. Assim, o estudo teve por objetivo desenvolver e calibrar um tensiômetro automatizado de baixo custo e alta eficiência no controle da irrigação, baseado em monitoramento em tempo real. A pesquisa foi conduzida nos Laboratórios de Hidráulica e Relação Água-Solo-Planta-Atmosfera pertencentes à Universidade Federal da Grande Dourados (UFGD), em Dourados, MS, com solo classificado como Oxisol. Foram utilizados transdutores de pressão e um microcrontrolador capazes de assimilar a pressão no interior dos tensiômetros e transformá-la em leituras de potencial matricial de água no solo - Ψm. Desta forma, realizou-se a calibração comparando as diferentes leituras do transdutor e do tensímetro digital de agulha. Foram aplicadas diferentes tensões para obtenção da curva de umidade do solo, partindo do ponto mais úmido (saturado) para o mais seco (solo seco em estufa), coletando 20 pontos válidos. Posteriormente, os dados foram submetidos ao teste de normalidade, com posterior análise estatística e modelos de curva de regressão. Foram verificados ajustes lineares com altos valores de coeficiente de determinação (R2 = 0,99), sendo o sistema automatizado construído, capaz de monitorar a tensão de água do solo em tempo real.

ABSTRACT Knowing the soil moisture available to plants is important for adequate management of water use in agricultural farms, with automated methods being the most accurate. However, acquisition costs are high and most of the commercially available irrigation controllers still work using pre-set times. This study aimed to develop and calibrate a low-cost automated tensiometer with high efficiency in irrigation control, based on real-time monitoring. The research was conducted at the Laboratories of Hydraulics and of Water Soil Plant and Atmosphere Relationship, which belong to the Federal University of Grande Dourados (UFGD), in Dourados, MS, Brazil, with soil classified as an Oxisol. Pressure transducers and a microcontroller were used to assimilate the pressure inside tensiometers and transform it into readings of soil water matric potential (Ψm). Thus, the calibration was carried out by comparing the different readings of the transducer and digital tension meter. Different tensions were applied to obtain a soil moisture curve, starting from the most humid point (saturated) to the driest one (oven-dried soil), collecting 20 valid points. Subsequently, the data were subjected to the normality test, with subsequent statistical analysis and regression curve models. Linear adjustments with a high coefficient of determination (R2 = 0.99) were observed, with the automated system built in this study being capable of monitoring soil water tension in real-time.

ABSTRACT One of the limitations to producing irrigated forages is setting suitable biometric parameters to establish the entrance of animals to grazing areas. Such parameters can be measured or even estimated. Estimates are advantageous for being practical and able to be used for grazing optimization. This study aimed to evaluate the correlation among growing degree-days (GDD), canopy height (CH), leaf area index (LAI), and number of cycle days (NCD) of Guinea grass (Panicum maximum cv. Mombaça) and Bermuda grass (Cynodon spp. Tifton 85) single cropped for one year and overseeded with black oat and ryegrass in the autumn-winter season. The study was carried out from February 2016 to February 2017, and forage crops were sprinkle irrigated. LAI and CH were measured twice a week, at intervals of 3 and 4 days. These parameters were correlated to GDD accumulation at each cutting cycle (CC). All the correlations showed high coefficients in linear fits. For spring-summer cycles, Guinea grass in exclusive cultivation showed the highest averages for CH and LAI, being 102.3 cm and 5.93, respectively. For autumn- winter cycles, when this grass was overseeded, it showed an LAI value similar to that when single cropped, which was of about 5.6. Yet single Bermuda grass presented lower values of LAI (one unit lower) and CH (16.4 cm lower) in the autumn-winter season when compared to that overseeded. The spring-summer cycles of Guinea grass had a duration of 24 days, after which no increase in leaf production was registered.

Abstract This study was carried out with the objective of assessing grain yield, economic analysis and energy balance of three sunflower genotypes with and without irrigation. The experiment was installed in the Experimental Farm of the Faculty of Agrarian Sciences of the Federal University of Grande Dourados in the 2011/2012 and 2012/2013 harvests in Dourados-MS, Brazil. The experimental design used was a random complete block design with subdivisions, with and without irrigation (plots), with three genotypes (subplots) and four replications, constituting 24 plots. There were no differences in productivity among the genotypes. The irrigation increased the operational cost of the sunflower crop production, but it did not economically obstruct the activity, due to the increase of productivity of 74.5% and 30% in the harvests of 2011/2012 and 2012/2013. The energy ratios of the sunflower crop were not altered by irrigation, equal to 5.7 and 8.7 in the harvests of 2011/2012 and 2012/2013, respectively.

RESUMO Uma das dificuldades na utilização de lisímetros de pesagem é a quantificação do volume drenado. Usualmente, tal volume é medido por meio de um fosso de acesso em sua base, cuja instalação é inviável em lisímetros de pequenas dimensões. Assim, este trabalho objetivou desenvolver, instalar, calibrar e verificar a eficiência de lisímetros de pesagem com sistemas de drenagem automatizados testando sua funcionalidade no campo. Cada lisímetro foi composto de uma caixa d’água circular de PVC, com 1,22 m de diâmetro e profundidade de 0,58 m, montada sobre uma estrutura metálica com 3 células de carga cada uma com capacidade nominal de 500 kg. O sistema de drenagem foi formado por um pequeno reservatório com capacidade de 10 L, uma estrutura de pesagem composta por uma célula de carga com capacidade nominal de 30 kg e uma válvula solenoide acionada automaticamente por um dispositivo eletrônico acoplado a um datalogger, que registrou os dados de ambos, do lisímetro e do sistema de drenagem. Foram realizadas calibrações de dois lisímetros e sistema de drenagem, cujos resultados foram equações ajustadas com correlação significativa (R2 > 0,9999) para ambos. Durante os testes, o sistema de drenagem foi acionado várias vezes após receber aproximadamente 63,4 L de água por precipitação, apresentando bom desempenho.

ABSTRACT Quantification of the drained volume is one of the difficulties involved in using weighing lysimeters. Typically, this volume is measured by accessing a moat at the base of a lysimeter. However, it is not feasible to install the moat in small devices. Thus, the aim of this study involves developing, installing, calibrating, and checking the efficiency of small weighing lysimeters with automated drainage systems to test their functionality in field conditions. Each lysimeter is composed of a round PVC water tank with a diameter of 1.22 m and a depth of 0.58 m that is placed over a metal frame with three electronic load cells with the nominal capacity of each cell corresponding to 500 kg. The drainage system is composed of a small reservoir with a volume of 10 L, a weighing structure composed of a load cell with a nominal capacity of 30 kg, and an automatic solenoid valve driven by a device coupled to a data logger that records the data from the lysimeter and from the drainage system. Two calibrations are performed for the lysimeter as well as the drainage system to obtain equations with significant correlations (R2 > 0.9999). The drainage system was activated several times during the tests after receiving approximately 63.4 L of water from rainfall, and this in turn indicated a good performance.

ABSTRACT The pasture irrigation has expanded, mostly in small areas in order to boost the production system, along with the use of soil improvement techniques and high-productivity grasses. Thus, this study, carried out on a small dairy farm property, aimed to evaluate the productivity, botanical composition and nutritive value of Tifton 85 with different nitrogen (N) doses, in the presence and absence of irrigation. The experimental design was a randomized block in a split-plot design with four replications, plots Non-irrigated and Irrigated. The subplots consisted of nitrogen doses: 25 kg ha−1 cycle−1 of N, 50 kg ha−1 cycle−1 of N, 75 kg ha−1 cycle−1 of N and 100 kg ha−1 cycle−1 of N. The irrigation increased the productivity in an average of 3,626.5 kg ha−1 cycle−1, with higher leaf stem ratio of 1.3, increasing the crude protein content of the pasture. The productivity responded quadratically to nitrogen fertilization with increases up to 84 kg N ha−1 cycle−1 with slight linear decrease of dead matter. There were linear increments of crude protein and digestibility “in vitro” of dry matter in function of applied nitrogen.

O trabalho foi conduzido em uma propriedade de atividade leiteirana município de Xambrê, região Noroeste do Paraná, no período de março de 2011 a fevereiro de 2012 com o objetivo de avaliar a produtividade e a composição botânica do capim Tifton 85 com e sem irrigação sob doses de nitrogênio. As parcelas experimentais foram implantadas com delineamento de blocos ao acaso com e sem irrigação e as subparcelas por meio de quatro doses de nitrogênio: 0, 20, 40 e 60 kg ha-1 ciclo de pastejo-1, com quatro repetições. A produtividade em matéria seca (MS) foi maior sob irrigaçãocrescendo de forma linear à adubação nitrogenada. Na dose de 60 kg N ha-1 foram obtidas produtividades iguais a 39279 e 27826 kg MS ha-1, com e sem irrigação, respectivamente. A relação folha colmo não foi afetada pela irrigação. A média geral do percentual de material morto com e sem irrigação, foi igual a 13 e 17%, respectivamente.

The study was conducted on a dairy farm in the municipality of Xambre, Northwest region of Parana, in the period from March 2011 to February 2012 to evaluate the yield and botanical composition of Tifton 85 with and without irrigation under nitrogen doses. The experimental plots were implanted in completely randomized blocks with and without irrigation and subplots through four nitrogen levels: 0, 20, 40 and 60 kg ha-1 per grazing cycle, with four replications. The yield in dry matter (DM) was higher under irrigation, responding linearly to increasing nitrogen fertilization. At a dose of 60 kg N ha-1 yields of 39279 and 27826 kg DM ha-1 were obtained, with and without irrigation, respectively. The leaf stem ratio was not affected by irrigation. The overall mean percentage of dead material with and without irrigation was equal to 13 and 17%, respectively.

O trabalho foi conduzido no período de abril a novembro de 2012, em uma propriedade de produção leiteira, no município de Mariluz, Região Noroeste do Paraná, com o objetivo de avaliar a produtividade, a composição botânica e o valor nutritivo do capim Tifton 85 sobressemeado com aveia, na presença e ausência de irrigação. O delineamento experimental foi de blocos casualizados em parcelas sub-subdivididas, com 4 repetições. As parcelas foram sem e com irrigação. As subparcelas foram constituídas de sobressemeaduras de aveia: FMS 2, IAPAR 61, IPR 126 e um tratamento com o Tifton 85 exclusivo. Os ciclos de coleta compuseram as sub-subparcelas. A irrigação incrementou a produtividade da pastagem com média de 2760,4 kg ha-1 ciclo-1, com a maior relação folha/colmo de 2,8, aumentando a digestibilidade da matéria seca. Os valores de proteína bruta foram maiores no irrigado e na média do irrigado e não irrigado, diminuíram ao longo dos ciclos de coleta de 18,6 para 13,6%. As maiores produtividades foram obtidas por meio das sobressemeaduras das aveias FMS 2 e IPR 126. O Tifton 85 exclusivo apresentou o maior valor de fibra em detergente neutro e o menor valor de digestibilidade.

The study was conducted from April to November, 2012, at a farm of dairy products in the municipality of Mariluz, Nortwest of Parana, with the objective to evaluate the productivity, botanical composition and nutritive value of Tifton 85 overseeding with oats, in the presence and absence of irrigation. The experimental design was a randomized block in split-plot with four replications. The plots were with and without irrigation. The subplots consisted of oats overseeding: FMS 2, IAPAR 61, IAPAR 126 and a treatment with Tifton 85 alone. The collection cycles composed the split plots. Irrigation increased pasture productivity with mean production of 2760.4 kg ha-1 cycle-1 with higher leaf/stem ratio of 2.8, increasing dry matter digestibility. The values of crude protein were higher in irrigated and decreased in non-irrigated and irrigated, along the collection cycles from 18.6 to 13.6%. The highest productivities were obtained through overseeding with oats FMS 2 and IPR 126. Tifton 85 alone showed the greatest amount of neutral detergent fiber and lesser digestibility.

O trabalho foi conduzido no período de maio a setembro de 2012, no Campus da Universidade Federal da Grande Dourados, com o objetivo de avaliar a produtividade e os componentes morfológicos e produtivos da cultura da canola (híbrido Hyola 61) submetidos a diferentes doses de nitrogênio em cobertura e irrigação. O delineamento experimental foi em blocos casualizado em esquema de parcelas subdivididas, com quatro repetições. As parcelas foram constituídas em irrigado e não irrigado. As subparcelas foram constituídas por três tratamentos com adubação nitrogenada em cobertura: 30, 60 e 90 kg ha-1 de nitrogênio. Com o uso da irrigação obtiveram-se os melhores resultados na altura de plantas, massa seca da parte aérea e no número de síliqua por planta. O teor de óleo e a massa de mil grãos apresentaram acréscimos significativos em função da irrigação e das doses de adubação nitrogenada. A produtividade sob irrigação foi superior à não irrigada, com valores iguais a 3145,65 e 1354,45 kg ha-1, respectivamente.

The study was conducted in the May-September 2012 at the Universidade Federal da Grande Dourados, with the main to evaluate the productivity, morphological and productive components of canola (Hybrid Hyola 61) crop under different levels of nitrogen (topdressing) and irrigation. The experimental design was randomized blocks in a split-plot with four replications. The plots were irrigated and no irrigated. The subplots were three treatments with nitrogen (topdressing) doses of 30, 60 and 90 kg ha-1. With the use of irrigation crop attained better results in plant height, shoot dry mass and number of siliqua per plants. The oil content and thousand grain weights showed significant increases as a function of irrigation and nitrogen doses. The yield under irrigation was higher than non-irrigated, with values equal to 3145.65 and 1354.45 kg ha-1, respectively.