First Steps Towards RAT: A Protocol for Documenting Data Use in the Agent-Based Modeling Process

While there is a number of frameworks and protocols in Agent-Based Modeling (ABM) that support the documentation of different aspects of a simulation study, it is surprising to find only a small number dealing with the handling of data. Here we present the results of discussions we had on the topic at the Lorentz Center workshop on Integrating Qualitative and Quantitative Evidence using Social Simulation (8-12 April 2019, Leiden, the Netherlands). We believe that important distinctions to be considered in the context of data use documentation are the differences of data use in relation to modeling approaches (theory driven etc.) and data documentation needs at the different stages in the modeling process (conceptualization, specification, calibration, and validation). What we hope to achieve by presenting this paper at this conference, with the help of the community, is to move forward the development of a generally acceptable protocol for documenting data use in the ABM process

Peanut yield under irrigation levels in off-season cultivation

Water deficit is considered the most critical environmental factor for peanut production in Brazil, as it constitutes one of the major constraints to the expansion of its cultivation in the suitable crop zones of the country. Determining crop water demand is fundamental to increasing yield with lower water consumption. The present study aimed to evaluate the effects of full and deficit irrigation levels (L1 = 8%, L2 = 27%, L3 = 63%, L4 = 94% and L5 = 100% replenishment of crop evapotranspiration) on the development, growth and yield of peanut crop sown in two times, February and March. Treatments were distributed in a split-plot randomized complete block design, with four replicates, using a line-source sprinkler system. Irrigation depths from 65 to 314 mm were applied with the levels L1 to L5 during the first and second cropping cycles. Full irrigation with sowing in March was more advantageous due to yield increase of up to 30% compared to sowing in February, but crop cycle was 25 days longer. Water stress caused by deficit irrigation reduced plant height, seed mass and pod yield, while full irrigation (L5) led to yields from 4,141 to 5,102 kg ha-1 for February and March, approximately three times higher than those obtained with the lowest irrigation level (L1). Highlights Peanut has great importance in the food and industry of several countries. The results of this research apply to regions that require irrigation, which is of about 70% of the areas of the globe with this legume. This paper contributes with information that emphasizes the possibility of cultivation in the drought season, aiming at the expansion of the crop and the production of quality seeds using irrigation.Water deficit is considered the most critical environmental factor for peanut production in Brazil, as it constitutes one of the major constraints to the expansion of its cultivation in the suitable crop zones of the country. Determining crop water demand is fundamental to increasing yield with lower water consumption. The present study aimed to evaluate the effects of full and deficit irrigation levels (L1 = 8%, L2 = 27%, L3 = 63%, L4 = 94% and L5 = 100% replenishment of crop evapotranspiration) on the development, growth and yield of peanut crop sown in two times, February and March. Treatments were distributed in a split-plot randomized complete block design, with four replicates, using a line-source sprinkler system. Irrigation depths from 65 to 314 mm were applied with the levels L1 to L5 during the first and second cropping cycles. Full irrigation with sowing in March was more advantageous due to yield increase of up to 30% compared to sowing in February, but crop cycle was 25 days longer. Water stress caused by deficit irrigation reduced plant height, seed mass and pod yield, while full irrigation (L5) led to yields from 4,141 to 5,102 kg ha-1 for February and March, approximately three times higher than those obtained with the lowest irrigation level (L1). Highlights Peanut has great importance in the food and industry of several countries. The results of this research apply to regions that require irrigation, which is of about 70% of the areas of the globe with this legume. This paper contributes with information that emphasizes the possibility of cultivation in the drought season, aiming at the expansion of the crop and the production of quality seeds using irrigation

Uniformity of water application to central pivot and to super 10 sprayer

O aumento da preocupação mundial com o aproveitamento e uso da água e a expansão da agricultura irrigada exigem otimização da eficiência de seu uso, destacando-se a sua uniformidade de aplicação, que influencia a otimização do uso da água pelas plantas. Objetivou-se, com o presente estudo, comparar a uniformidade de aplicação de água de um aspersor, obtido em condições de campo com o catálogo do fabricante, além de avaliar a uniformidade de aplicação de água de um pivô-central com aspersores novos e usados. Em condições de campo, a uniformidade de aplicação de água do aspersor SUPER 10 foi inferior à informada no catálogo do fabricante. Não se recomenda a utilização do aspersor SUPER 10 em espaçamentos iguais ou superiores a 12 x 12 m. Além disso, em culturas com alto valor agregado, como hortaliças, indica-se a utilização desse aspersor no espaçamento de 8 x 8 m. O pivô central apresenta boa uniformidade de aplicação de água, com CUH de 87,4% e CUD de 82,8%, além de aplicar uma lâmina média de 7,39 mm. The increase in global concern with the use and use of water and the expansion of irrigated agriculture require optimization of the efficiency of its use, highlighting its uniformity of application, which influences the optimization of water use by plants. The objective of this study was to compare the uniformity of water application of a sprinkler, obtained in field conditions with the manufacturer's catalog, and to evaluate the uniformity of water application of a central pivot with new and used sprinklers. Under field conditions, the water application uniformity of the SUPER 10 sprinkler was lower than that reported in the manufacturer's catalog. It is not recommended to use the SUPER 10 sprinkler in spacings equal to or greater than 12 x 12 m. In addition, in cultures with high added value, such as vegetables, the use of this sprinkler in the 8 x 8 m spacing is indicated. The central pivot shows good uniformity of water application, with CUH of 87.4% and CUD of 82.8%, besides applying a mean blade of 7.39 mm.El aumento de la preocupación mundial con el aprovechamiento y uso del agua y la expansión de la agricultura irrigada exigen optimización de la eficiencia de su uso, destacándose la uniformidad de aplicación, que influye en la optimización del uso del agua por las plantas. Se objetivó, con el presente estudio, comparar la uniformidad de aplicación de agua de un aspersor, obtenido en condiciones de campo con el catálogo del fabricante, además de evaluar la uniformidad de aplicación de agua de un pivote central con aspersores nuevos y usados. En condiciones de campo, la uniformidad de aplicación de agua del aspersor SUPER 10 fue inferior a la indicada en el catálogo del fabricante. No se recomienda el uso del aspersor SUPER 10 en espaciamientos igual o superiores a 12 x 12 m. Además, en cultivos con alto valor agregado, como hortalizas, se indica la utilización de este aspersor en el espaciado de 8 x 8 m. El pivote central presenta buena uniformidad de aplicación de agua, con CUH de 87,4% y CUD del 82,8%, además de aplicar una lámina media de 7,39 mm

Effects of different levels of irrigation suppression and fertigation on potato yield

With the limitation in the availability of water for agriculture and the high costs of fertilizers, it is necessary to adopt strategies for water and nutritional management of agricultural crops. The objective of this study was to evaluate the morphological and physiological characteristics and productivity of potato under the influence of suppression of irrigation and fertigation in Jaboticabal, SP, Brazil. The experiment was carried out in randomized blocks, conducted in the field, using a 3 x 2 factorial scheme. Different times of irrigation suppression were studied at 80, 90 and 100 days after planting, along with forms of fertigation, following the rate of crop absorption and equivalent fertigation. The imposition of irrigation suppression at 100 days, linked to fertigation following the rate of crop absorption, showed a positive effect on the aerial fresh mass of the potato variety studied, especially promoting the increase in productivity, which was 47.82 t ha-1, and efficiency in water use, which was 10.53 kg of tubers per cubic meter of water. This observation indicates that the application of fertilizers, in sync with the needs of the crop, can improve the efficiency of water use and increase productivity. These findings highlight the importance of integrated strategies to optimize potato cultivation and make it more resistant to adversity, seeking a more sustainable and productive agriculture.With the limitation in the availability of water for agriculture and the high costs of fertilizers, it is necessary to adopt strategies for water and nutritional management of agricultural crops. The objective of this study was to evaluate the morphological and physiological characteristics and productivity of potato under the influence of suppression of irrigation and fertigation in Jaboticabal, SP, Brazil. The experiment was carried out in randomized blocks, conducted in the field, using a 3 x 2 factorial scheme. Different times of irrigation suppression were studied at 80, 90 and 100 days after planting, along with forms of fertigation, following the rate of crop absorption and equivalent fertigation. The imposition of irrigation suppression at 100 days, linked to fertigation following the rate of crop absorption, showed a positive effect on the aerial fresh mass of the potato variety studied, especially promoting the increase in productivity, which was 47.82 t ha-1, and efficiency in water use, which was 10.53 kg of tubers per cubic meter of water. This observation indicates that the application of fertilizers, in sync with the needs of the crop, can improve the efficiency of water use and increase productivity. These findings highlight the importance of integrated strategies to optimize potato cultivation and make it more resistant to adversity, seeking a more sustainable and productive agriculture

Comparison of equations for the estimation of head loss in polyethylene tube

La determinación de la pérdida de carga en proyectos de riego no es utilizada por ser un método de baja practicidad. Para ello, existen ecuaciones que estiman esa variable, basándose en características de las tuberías y del proyecto, tales como material del tubo, diámetro y caudal del sistema. De esta forma, se objetivó evaluar la mejor ecuación para la estimación de la pérdida de carga en tubería de polietileno con diámetro interno de 25 mm, comparando los resultados a la pérdida de carga determinada en manómetro de mercurio. El experimento fue realizado en lo laboratorio de irrigación de la FCAV / Unesp, Jaboticabal en junio de 2017. La estimación de la pérdida de carga fue realizada por la ecuación de Hazen-Williams y de Darcy-Weisbach, siendo que para esa última el factor de fricción (f ) fue estimado por los modelos de Swamee y Jain y de Blasius. Las ecuaciones fueron comparadas con los datos determinados en columna de mercurio en 5 caudales, con valores que varían de 1,55 m3 h-1 a 5,15 m3 h-1. La estimación de la pérdida de carga por el método de Swamee y Jain sobreestimó los valores determinados en la columna de mercurio. Hasta el caudal de 5,15 m3  h-1 el método de Hazen-Williams presentó la menor variación y, consecuentemente, la mayor eficiencia de estimación de pérdida de carga en relación a los valores determinados para la tubería de polietileno de diámetro de 25 mm.A determinação da perda de carga em projetos de irrigação não é utilizada por ser um método de baixa praticidade. Para isso, existem equações que estimam essa variável, embasando-se em características das tubulações e do projeto, tais como material do tubo, diâmetro e vazão do sistema. Dessa forma, objetivou-se avaliar a melhor equação para a estimativa da perda de carga em tubulação de polietileno com diâmetro interno de 25 mm, comparando os resultados à perda de carga determinada em manômetro de mercúrio. O experimento foi realizado no laboratório de irrigação da FCAV/Unesp, Jaboticabal em junho de 2017. A estimativa da perda de carga foi realizada pela equação de Hazen-Williams e de Darcy-Weisbach, sendo que para essa última o fator de atrito (f) foi estimado pelos modelos de Swamee & Jain e de Blasius. As equações foram comparadas com os dados determinados em coluna de mercúrio em 5 vazões, com valores variando de 1,55 m3 h-1 a 5,15 m3 h-1. A estimativa da perda de carga pelo método de Swamee & Jain superestimou os valores determinados na coluna de mercúrio. Até a vazão de 5,15 m3 h-1 o método de Hazen-Williams apresentou a menor variação e, consequentemente, a maior eficiência de estimativa de perda de carga em relação aos valores determinados para a tubulação de polietileno com diâmetro de 25 mm. The determination of the head loss in irrigation projects is not used because it is a low practical method. For this, there are equations that estimate this variable, based on characteristics of the pipes material, diameter and system flow. Thus, the objective of this study was to evaluate the best equation for estimating the head loss in polyethylene tubing with internal diameter of 25 mm, comparing the results to the head loss determined in a mercury manometer. The experiment was carried out in the irrigation laboratory of the FCAV/Unesp, Jaboticabal, in June 2017. The estimation of the head loss was performed by the Hazen-Williams and Darcy-Weisbach equation, with the friction factor (f) estimated by Swamee and Jain and Blasius models. The equations were compared with the data determined in column of mercury in five flows, with values ranging from 1.55 m3 h-1 a 5.15 m3 h-1. The estimation of the head loss by Swamee and Jain method overestimated the values determined in the mercury column. Up to the 5.15 m3 h-1 flow the Hazen-Williams method presented the lowest variation and, consequently, the higher efficiency of estimated of head loss in relation to the values determined for polyethylene tubing with a diameter of 25 mm

Impact of Si on C, N, and P stoichiometric homeostasis favors nutrition and stem dry mass accumulation in sugarcane cultivated in tropical soils with different water regimes

Studies with silicon (Si) in sugarcane indicate a greater response in productivity in plants under stress, and the underlying mechanisms of Si in the crop are poorly reported. In this context, the benefits of Si in the crop’s stem production are expected to occur at the C:N:P stoichiometry level in plant tissues, benefiting plants with and without stress. However, the extension of this response may vary in different soils. Thus, this research aimed to evaluate if fertigation with Si modifies the C:N:P stoichiometry and if it can increase sugarcane’s nutritional efficiency and vegetative and productive parameters. Therefore, three experiments were installed using pre-sprouted seedlings to cultivate sugarcane in tropical soils belonging to the Quartzarenic Neosol, Eutrophic Red Latosol, and Dystrophic Red Latosol classes. The treatments comprised a 2 × 2 factorial scheme in each soil. The first factor was composed without water restriction (water retention = 70%; AWD) and with water restriction (water retention = 35%; PWD). The second factor presented Si concentrations (0 mM and 1.8 mM) arranged in randomized blocks with five replications. Fertigation with Si increases the Si and P concentration, the C and N efficiency, the C:N ratio, and the dry mass production. However, it decreases the C and N concentration and the C:P, C:Si, and N:P ratios in sugarcane leaves and stems regardless of the water regime adopted in the three tropical soils. Cluster and principal components analysis indicated that the intensity of the beneficial effects of Si fertigation on sugarcane plants varies depending on the cultivation soil and water conditions. We found that Si can be used in sugarcane with and without water stress. It changes the C:N:P homeostasis enough to improve the nutritional efficiency of C, P, N, and, consequently, the dry mass accumulation on the stems, with variation in the different cultivated soils