Determining water use of sorghum from two-source energy balance and radiometric temperatures

Estimates of surface actual evapotranspiration (ET) can assist in predicting crop water requirements. An alternative to the traditional crop-coefficient methods are the energy balance models. The objective of this research was to show how surface temperature observations can be used, together with a two-source energy balance model, to determine crop water use throughout the different phenological stages of a crop grown. Radiometric temperatures were collected in a sorghum (<i>Sorghum bicolor</i>) field as part of an experimental campaign carried out in Barrax, Spain, during the 2010 summer growing season. Performance of the Simplified Two-Source Energy Balance (STSEB) model was evaluated by comparison of estimated ET with values measured on a weighing lysimeter. Errors of ±0.14 mm h<sup>−1</sup> and ±1.0 mm d<sup>−1</sup> were obtained at hourly and daily scales, respectively. Total accumulated crop water use during the campaign was underestimated by 5%. It is then shown that thermal radiometry can provide precise crop water necessities and is a promising tool for irrigation management

Transpiración nocturna en vid

Se presentan las medidas de transpiración media cada quince minutos, de la vid (Vitis vinifera cv. Tempranillo), en tres periodos fenológicos del cultivo: cerrado de racimo, envero y maduración. El estudio se realizó en dos plantas de 16 años de edad, a un marco de plantación de 3 m x 1,5 m, regadas mediante goteo y plantadas en un lisímetro de pesada continua monolítico de 9 m2 de superficie. Con la finalidad de poder medir la transpiración, la superficie del lisímetro fue cubierta con una lona impermeable, para evitar la pérdida de agua por evaporación, dejándose únicamente al aire libre el cultivo; de esta manera, las medidas registradas de pérdida de peso se debieron únicamente al efecto de la transpiración. Los resultados indicaron transpiración antes y después de la salida del sol, oscilando los valores de un 7% a un 16%, con respecto a la transpiración total del día.Ministerio de Economía y Competitividad AGL2014- 54201-C4-4-RMinisterio de Economía y Competitividad RTA2011-00100-C05-04Ministerio de Economía y Competitividad RTA 2014-00049-C05-0

¿Es posible mejorar la eficiencia en el uso del agua de un viñedo mediante un acolchado orgánico del suelo?

El objetivo de este trabajo fue evaluar el efecto que un acolchado orgánico del suelo (restos de poda) puede tener sobre la evapotranspiración del cultivo (ETc) de la vid con el fin de mejorar la eficiencia en el uso del agua. El estudio se realizó durante la campaña de 2015 en la finca “Las Tiesas”, Albacete (España). Las medidas se llevaron a cabo en un lisímetro monolítico de pesada ubicado en el centro de una parcela de vid (Vitis vinífera L., cv. Tempranillo) de 1 ha de superficie, y con cepas plantadas a un marco de 3 x 1,5 m y conducción en espaldera. Se llevaron a cabo tres ciclos de medidas, cada uno consistió en mantener el suelo desnudo durante los dos primeros días, los dos siguientes se cubrió la superficie del lisímetro con un acolchado orgánico (restos de poda de la vid) y los dos últimos días se cubrió el lisímetro con un acolchado inorgánico (lona de plástico). Los resultados indican que para la misma demanda evaporativa y fracción de cubierta vegetal, el acolchado orgánico redujo la ETc de la vid algo más de un 17%, mientras que el plástico la redujo un 25%. Los resultados obtenidos indican que con el acolchado orgánico sigue produciéndose una cierta evaporación de agua desde el suelo, pero se reduce considerablemente la ETc pudiéndose mejorar la eficiencia en el uso del agua.Ministerio de Economía y Competitividad FEDER AGL2014-54201-C4-4- RRTA 2011-00100-C05-04RTA 2014-00049-C05-0

Standard single and basal crop coefficients for vegetable crops, an update of FAO56 crop water requirements approach

ReviewMany research papers on crop water requirements of vegetables have been produced since the publication of the FAO56 guidelines in 1998. A review of this literature has shown that determination of crop evapotranspiration (ETc) using the Kc-ETo approach, i.e., the product of the specific crop coefficient (Kc) by the reference evapotranspiration (ETo), is the most widely-used method for irrigation water management. Consequently, a review was made to provide updated information on the Kc values for these crops. The reviewed research provided various approaches to determine Kc in its single and dual versions. With this purpose, actual crop ET (ETc act ) was determined with lysimeters, or by performing the soil water balance using measured soil water content and computational models, or by using Bowen ratio energy balance and eddy covariance measurements, or by using remote sensing applications. When determining the basal Kc(Kcb), the partitioning of ETc act was evaluated using different approaches, though mainly using the FAO56 dual Kc method. Since the accuracy of experimentally-determined Kc and Kcb values depends upon the procedure used to compute ETo, as well as accuracy in determining and partitioning of ETc act , the adequacy of the measurement requirements for each approach was carefully reviewed. The article discusses in detail the conceptual methodology relative to crop coefficients and the requirements for transferability, namely distinguishing between actual and standard Kc and the need to appropriately use the FAO segmented Kc curve. Hence, the research papers selected to update and consolidate mid-season and end-season standard Kc and Kcb were those that computed ETo with the FAO56 PM-ETo equation; and that also used accurate approaches to determine and partition ETc act for pristine, non-stressed cropping conditions. Under these experimental conditions, the reported Kc and Kcb values relative to the mid- and end-season could be considered as transferable standard Kc and/or Kcb values after adjustment to the standard climate adopted in FAO56, where average RHmin = 45% and average u2 = 2 m s−1 over the mid-season and late season growth stages. For each vegetable crop, these standard values were then compared with the FAO56 tabulated Kc and Kcb values to define the updated values tabulated in the current article. In addition, reported ancillary data, such as maximum root zone depth, maximum crop height, and soil water depletion fraction for no water stress, were also collected from selected papers and tabulated in comparison with those given for the crops in FAO56. The presentation of updated crop coefficient results is performed by grouping the vegetables differently than in FAO56, where distinction is made according to their edible parts: (1) roots, tubers, bulbs and stem vegetables; (2) leaves and flowers vegetables; (3) fruit and pod vegetables; and (4) herbs, spices and special crops, with most of them being newly introduced herein. The updated Kc and Kcb of vegetable crops based on this review are generally coincident with those in FAO56, although slightly lower for several crops. Close agreement of selected paper values with FAO56 values provides good evidence of their quality and also confirms the reliability of the original FAO56 tabulated values. It is noteworthy that many papers surveyed from the past 20 years did not satisfy the adopted Kc requirements in terms of ETo computation method nor provide solid evidence of measurement accuracy for ETc act . It is recommended that future Kc research of vegetables should sufficiently address these issues with objectives broadened to provide more transferable data to other regions. Also, new data on vegetable Kc and Kcb values should be carefully scrutinized in the context of these results and those provided in FAO56info:eu-repo/semantics/publishedVersio

Registration of Great Northern Common Bean Cultivar ‘Coyne’ with Enhanced Disease Resistance to Common Bacterial Blight and Bean Rust

Great northern common bean (Phaseolus vulgaris L.) ‘Coyne’ (Reg. No. CV-287, PI 655574) was developed by the dry bean breeding program at the University of Nebraska Agricultural Research Division and released in 2008. It was bred specifically for adaptation to Nebraska growing conditions and for enhanced resistance to common bacterial blight (CBB), a major disease of common bean caused by the seed-borne bacterium Xanthomonas campestris pv. phaseoli (Smith) Dye, and bean common rust Uromyces appendiculatus (Pers.:Pers) Unger. Coyne is a great northern F7:8 line derived from a three-way cross (G95023/Weihing//BelMiNeb-RMR-11). The first cross was made in winter 2003. The F7:8 was tested in advanced yield trials at Scottsbluff and Mitchell, NE, and in growers’ fields in Nebraska. Yield of Coyne was only 47 kg ha–1 lower than ‘Marquis’ in Morrill and Scotts Bluff, NE, counties. Reaction of Coyne to CBB under field conditions was consistent across 3 yr at the West Central Research and Extension Center, North Platte, NE, where fi eld disease ratings of 3.2, 3.5, and 4.4 were recorded in 2005, 2006, and 2007, respectively. Coyne has the Ur-3 and Ur-6 genes for resistance to common bean rust and carries the single dominant hypersensitive I gene that provides resistance to all non-necrotic strains of Bean common mosaic virus. Coyne has bright white seed, blooms 44 d after planting, and is a midseason bean, maturing 91 d after planting

Influencia de la posición de las paletas en el rendimiento de una turbina de hélice con rotor de alabes rectos

El presente artículo pertenece al desarrollo del provecto de grado "Diseño y Construcción de una Turbina Hidráulica de 3 Kw

ESTIMACIÓN DE LA EVAPORACIÓN/TRANSPIRACIÓN EN UN CULTIVO DE TRIGO MEDIANTE RADIOMETRÍA TÉRMICA

[EN] This work shows the application of a two-source energy balance model, together with surface temperature measurements, to derive hourly and daily values of land surface energy fluxes of wheat, crop evapotranspiration (ETc) included. An experiment was carried out during the spring of 2014 in a wheat field located in the experimental farm of “Las Tiesas” in Barrax, Albacete. Soil and canopy radiometric temperatures were measured, as well as meteorological variables and biophysical parameters, from plantation to senescence. Results were compared to measurements in a weighing lysimeter installed within the wheat field. Estimation errors of ±0.10 mm h-1 and ±0.9 mm d-1 were obtained at hourly and daily scales, respectively. Cumulated value of ETc for the whole campaign was only 4% over that registered in the lysimeter. Furthermore, a percentage 30% - 70% between evaporation (E) and transpiration (T) components was obtained for the full campaign. Modeled values of the wheat crop coefficients were also retrieved and compared to those proposed by FAO56.[ES] En este trabajo se propone la aplicación de un modelo de balance de energía de dos fuentes que, junto con medidas de la temperatura de la superficie, proporcione valores horarios y diarios de los flujos energéticos en superficie, incluyendo la evapotranspiración real del cultivo de trigo (ETc). Para mostrar la aplicación y utilidad del método se realizó un experimento en la primavera de 2014 sobre una plantación de trigo situada dentro de la finca experimental “Las Tiesas” en el término de Barrax, Albacete. Se midieron temperaturas del suelo y de la vegetación, además de variables meteorológicas y parámetros biofísicos, desde el momento de la siembra hasta la recolección. Los resultados se compararon con las medidas de un lisímetro de pesada instalado en la parcela, obteniendo unos errores de estimación de ±0,10 mm h-1 y ±0,9 mm d-1 a escalas horaria y diaria, respectivamente. Por su parte el valor de ETc acumulado para toda la campaña fue solo el 4% mayor que el valor medido en el lisímetro. Además, el porcentaje entre la componente evaporativa (E) y transpirativa (T) fue de 30%-70% para el total de la campaña. El modelo también permite estimar los coeficientes de cultivo del trigo, y compararlos con los propuestos por FAO56.Sánchez, J.; López-Urrea, R.; Doña, C.; Caselles, V.; González-Piqueras, J. (2015). ESTIMACIÓN DE LA EVAPORACIÓN/TRANSPIRACIÓN EN UN CULTIVO DE TRIGO MEDIANTE RADIOMETRÍA TÉRMICA. En XXXIII CONGRESO NACIONAL DE RIEGOS. Valencia 16-18 junio de 2015. Editorial Universitat Politècnica de València. https://doi.org/10.4995/CNRiegos.2015.1504OCS