scholarly journals Dual crop coefficient for the early-cycle soybean cultivar SoyTech 815 RR

Author(s):  
Guilherme Bariviera ◽  
Rivanildo Dallacort ◽  
Paulo S. L. de Freitas ◽  
Joao D. Barbieri ◽  
Diego F. Daniel

ABSTRACT The objective of this study was to determine the dual crop coefficient of an early-cycle soybean cultivar for the city of Tangará da Serra, MT, Brazil, using high-precision lysimeters. The method used was the dual crop coefficient (dual Kc) of FAO Bulletin 56, constitued by soil evaporation coefficient (Ke), determined by microlysimeters, and by basal crop coefficient (Kcb), determined by weighing lysimeters. Reference evapotranspiration (ETo) was calculated using the Penman-Monteith equation. Soybean sowing and harvesting were performed in the 2015/16 season with spacing of 0.45 m between rows. The reference evapotranspiration (ETo) estimated for the cultivation period was 267.06 mm; the crop evapotranspiration was 323.61 mm throughout its cycle. The Kcb values determined by lysimeters for soybean cultivation were 0.47, 1.15 and 0.89 for the initial, intermediate and final stages, respectively; Ke values at the initial, intermediate and final stages were 0.94, 0.14 and 0.44, respectively.

Irriga ◽  
2018 ◽  
Vol 21 (2) ◽  
pp. 269 ◽  
Author(s):  
Vágna Da Costa Pereira ◽  
Gilberto Chohaku Sediyama ◽  
Magna Soelma Beserra De Moura ◽  
Thieres George Freire Da Silva ◽  
Luciana Sandra Bastos De Souza

EFICIÊNCIA DO USO DA ÁGUA EM VIDEIRA ‘SYRAH’ IRRIGADA NO SUBMÉDIO DO VALE SÃO FRANCISCO1 VÁGNA DA COSTA PEREIRA1; GILBERTO CHOHAKU SEDIYAMA2; MAGNA SOELMA BESERRA DE MOURA3; THIERES GEORGE FREIRE DA SILVA4 E LUCIANA SANDRA BASTOS DE SOUZA51Resultado da Dissertação de Mestrado do primeiro autor2Doutoranda em Meteorologia Agrícola – Departamento de Engenharia Agrícola – Universidade Federal de Viçosa – Campus Viçosa – 36570-900 – Viçosa, Minas Gerais, Brasil, [email protected]. Titular – Departamento de Engenharia Agrícola – Universidade Federal de Viçosa – Campus Viçosa – 36570-900 – Viçosa, Minas Gerais, Brasil, [email protected] – Núcleo Temático de Recursos Naturais – Embrapa Semiárido – 56302-970 – Petrolina, Pernambuco, Brasil, [email protected]. Adjunto – Departamento de Ciências Agrárias – Universidade Federal Rural de Pernambuco – Unidade Acadêmica de Serra Talhada – 56909-535 – Serra Talhada, Pernambuco, Brasil, [email protected]. Assistente – Departamento de Ciências Agrárias – Universidade Federal Rural de Pernambuco – Unidade Acadêmica de Serra Talhada – 56909-535 – Serra Talhada, Pernambuco, Brasil, [email protected]  1 RESUMO O estudo teve como objetivo estimar a eficiência do uso da água (EUA) na videira ‘Syrah’ irrigada no Submédio do Vale São Francisco, com base no rendimento em função da evapotranspiração da cultura e da transpiração máxima. Para isso, a evapotranspiração da cultura foi determinada pelo balanço de energia com base no método da razão de Bowen (ETcBERB), enquanto a transpiração máxima (TR) foi estimada pelo modelo de Penman-Monteith modificado com base no índice de área foliar da cultura. Os dados micrometeorológicos foram monitorados durante um ciclo produtivo por meio de uma estação automática localizada no parreiral. A evapotranspiração de referência (ETo) também foi calculada ao longo do experimento, pelo método de Penman-Monteith parametrizado no boletim 56 da FAO. A ETo e a ETcBERB corresponderam ao valor total de 474,0 e 376,4 mm ciclo-1, com valor médio diário de 3,9 e 3,1 mm, respectivamente. A TR oscilou entre 3,5 e 0,9 mm d-1, com volume total durante o ciclo de 284,4 mm. A EUA, com base no total de água consumida e transpirada, foi de 1,17 kg m-3 e 1,55 kg m-3, respectivamente. O método do BERB e o modelo de Penman-Monteith modificado para plantas isoladas apresentaram resultados confiáveis para estimativa da EUA sob as condições climáticas da região do Submédio do Vale São Francisco. No entanto, torna-se necessário que novos estudos nesse sentido com a cultura da videira para produção de vinhos sejam realizados, principalmente nesta região Semiárida, onde a maioria das pesquisas voltadas para o manejo do vinhedo ainda estão em desenvolvimento. Palavras-chave: semiárido, evapotranspiração, razão de Bowen, transpiração máxima   PEREIRA, V. C.; SEDIYAMA, G. C.; MOURA, M. S. B.; SILVA, T. G. F.; SOUZA, L. S. B.WATER USE EFFICIENCY IN IRRIGATED "SYRAH'' GRAPE PLANTATION AT SÃO FRANCISCO RIVER VALLEY  2 ABSTRACT The objective of this work was to evaluate the water use efficiency (WUE) in  irrigated ‘Syrah’ grapevine plantation at São Francisco River valley, on the basis of yields as a function of crop evapotranspiration and maximum transpiration. To this end, the crop evapotranspiration was determined by energy balance based on the Bowen ratio method (ETcBERB), while the maximum transpiration (TR) was estimated by the modified Penman-Monteith equation based on the crop leaf area index. The micrometeorological data within the vineyard canopy were monitored using an automatic micrometeorological station, during a productive cycle. The reference evapotranspiration (ETo) was also calculated during that period using the FAO parameterized Penman-Monteith equation. The reference evapotranspiration (ETo) and the crop evapotranspiration determined by BREB method (ETcBERB), during the crop cycle, were 474.0 and 376.4 mm cycle-1, respectively, with a daily average of 3.9 and 3.1 mm. The TR rate ranged between 3.5 and 0.9 mm d-1, with total volume during 284.4 mm cycle -1. The WUE, on the basis of the total water consumed and transpiration, was 1.17 kg m-3 and 1.55 kg m-3, respectively. The BERB method and the Penman-Monteith model modified to isolated plants showed reliable results to estimate the WUE under the climatic conditions of São Francisco River valley. However, new studies on grape culture for wine production are necessary, especially in this semiarid region, where most researches focused on the vineyard management are still in development. Keywords: Bowen ratio. Evapotranspiration. Maximum transpiration. Semiarid. 


2017 ◽  
Vol 28 (2) ◽  
pp. 509
Author(s):  
Martha Constanza Daza Torres ◽  
Hugo Stiven Meneses Carvajal ◽  
Aldemar Reyes Trujillo ◽  
Norberto Urrutia Cobo

This study aimed to determine the crop coefficient (Kc) curve for stevia (Stevia rebaudiana Bertoni) in Candelaria, Valle del Cauca, Colombia. The experiment was conducted during the first half of 2015. In a plot planted with stevia, were located three drainage lysimeters arranged randomly and a portable weather station to determine climatic variables necessary for calculating an evapotranspiration reference (ETo), using the Penman Monteith equation. Soil eld capacity moisture was determined and regular monitoring of both, soil moisture and drainage water depth were performed. Irrigation was applied using an exhaustion coefficient of 10% to bring it back to field capacity moisture. Statistical analyzes were performed and Kc was calculated from the ratio of crop evapotranspiration (ETc) to ETo, for each plant in phenological phase. With condidence of 95% Kc for stevia were: growth stage (54 days after transplantation, ddt) 0.86 ± 0.12, mature stage (55-72 ddt) 1.24 ± 0.10 and senescence stage (72-96 ddt) 0.85 ± 0.14. Water consumption of Stevia rebaudiana B., was 4753 m3/ha during its growing cycle of 96 days after transplantation. 


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Songhao Shang

Crop water requirement is essential for agricultural water management, which is usually available for crop growing stages. However, crop water requirement values of monthly or weekly scales are more useful for water management. A method was proposed to downscale crop coefficient and water requirement from growing stage to substage scales, which is based on the interpolation of accumulated crop and reference evapotranspiration calculated from their values in growing stages. The proposed method was compared with two straightforward methods, that is, direct interpolation of crop evapotranspiration and crop coefficient by assuming that stage average values occurred in the middle of the stage. These methods were tested with a simulated daily crop evapotranspiration series. Results indicate that the proposed method is more reliable, showing that the downscaled crop evapotranspiration series is very close to the simulated ones.


Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 756 ◽  
Author(s):  
Alataway ◽  
Al-Ghobari ◽  
Mohammad ◽  
Dewidar

The determination of the water requirements and crop coefficient (Kc) of agricultural crops helps to create an appropriate irrigation schedule, and with the effective management of irrigation water. The aim of this research was to estimate the water requirement, Kc, and water-use efficiency (WUE) of potato using non-weighing-type lysimeters in four regions of the Kingdom of Saudi Arabia (Qassiem, Riyadh, Al-Jouf, and Eastern). Our results clearly show that the accumulated values of the measured crop evapotranspiration of potato derived from the lysimeters were 573, 554, 592, and 570 mm, while the accumulated values of the predicted crop evapotranspiration from Penman-Monteith equation based on FAO (Food and Agriculture Organization) were 651, 632, 672, and 647 mm for the Qassiem, Riyadh, Al-Jouf, and Eastern regions, respectively. The Kc values of potato obtained from the lysimeters were Kc initial (0.58, 0.54, 0.50, and 0.52), Kc middle (1.02, 1.05, 1.13, and 1.10), and Kc end (0.73, 0.74, 0.74, and 0.75) for the Qassiem, Riyadh, Al-Jouf, and Eastern regions, respectively. Based on the amount of water used and the yield achieved, the highest WUE (3.6 kg m−3) was observed in the Riyadh region, while the lowest WUE (1.5 kg m−3) was observed in the Al-Jouf region.


HortScience ◽  
2020 ◽  
Vol 55 (2) ◽  
pp. 244-250 ◽  
Author(s):  
Xuewen Gong ◽  
Shunsheng Wang ◽  
Cundong Xu ◽  
Hao Zhang ◽  
Jiankun Ge

Studies on dual crop coefficient method in a greenhouse require accurate values of reference evapotranspiration (ETo). This study was conducted in a solar greenhouse at the experimental station of the Chinese Academy of Agricultural Sciences during 2015 and 2016. An automatic weather station was installed in the center of the same greenhouse to record weather parameters at 30-minute intervals. Five ETo models (Penman-Monteith, Penman, radiation, pan evaporation, and Priestley-Taylor) were employed, and their performance was evaluated using the dual crop coefficient method. The basal crop coefficient Kcb and soil evaporation coefficient Ke were adjusted according to the surrounding climate inside the greenhouse. Crop evapotranspiration (ETc) was continuously measured using sap flow system combined with microlysimeter in 2015 and weighing lysimeters in 2016. Daily ETo was simulated from the five models and compared with the measurements. Results show that the adjusted Kcb values were 0.15, 0.94, and 0.65 in 2015 and 0.15, 1.02, and 0.70 in 2016 at initial, midseason, and late-season, respectively. The Ke varies between 0.10 and 0.45 during the whole growth period. The ETc was ≈345 mm for drip-irrigated tomato in solar greenhouse at the whole growth stage. The radiation and pan evaporation models tend to overestimate ETo values. Results of the Penman-Monteith, Penman, and Priestley-Taylor models show comparatively good performance in estimating ETo. Considering the robustness and simplicity, the Priestley-Taylor was recommended as the first choice to estimate ETo of tomato grown in a solar greenhouse. This work can help farmers to optimize the irrigation scheduling based on an ETo model for solar greenhouse vegetables in northern China.


2013 ◽  
Vol 33 (5) ◽  
pp. 929-939 ◽  
Author(s):  
Talyana K. de Melo ◽  
José F. de Medeiros ◽  
José E. Sobrinho ◽  
Vladimir B. Figueiredo ◽  
Paulo S. de Souza

Aiming at contributing to an adequate management of water resources, this study aimed to analyze and compare evapotranspiration (ETc) and crop coefficients (Kc) of melon plants measured by a lysimeter and estimated according to the FAO 56 methodology, in the city of Mossoró, state of Rio Grande do Norte (RN), Brazil. In order to measure ETc, weighing lysimeters with an area of 2.25m² were used, with two repetitions. The Penman-Monteith equation parameterized by FAO was used to estimate the reference evapotranspiration, and crop coefficients were those recommended in FAO-56 Bulletin adjusted to local climatic conditions. The required climatic data and lysimeter measurements were collected by an automatic weather station installed at the site. The results were compared by means of statistical indicators: of precision (r), of accuracy (d), and performance (c), in daily and weekly intervals. The data estimated by the FAO 56 methodology were adjusted optimally to the values measured by the lysimeters in accordance with index "c" in the two time scales assessed, indicating the potential of the method proposed by FAO to irrigation management in the climatic conditions of Agripole Assú-Mossoró.


2017 ◽  
Vol 60 (6) ◽  
pp. 1965-1981 ◽  
Author(s):  
Kendall C. DeJonge ◽  
Kelly R. Thorp

Abstract. While methods for estimating reference evapotranspiration (ETo or ETr) and subsequent crop ET (ETc) via crop coefficient (Kc) and dual crop coefficient (Kcb, Ke) methods have been standardized since 2005 and 1998, respectively, the current version of the DSSAT cropping system model (CSM) has not been updated to fully implement these methods. In this study, two major enhancements to the model’s ET routines were evaluated: (1) addition of the ASCE Standardized Reference Evapotranspiration Equation so that both grass and alfalfa reference ET were properly calculated using the most recent reference ET standard and (2) addition of the FAO-56 dual crop coefficient approach to determine potential ET, which combined an evaporative coefficient (Ke) for potential evaporation with a dynamic basal crop coefficient (Kcb) for potential transpiration as a function of simulated leaf area index. Previously published data sets for maize in Colorado (five years) and cotton in Arizona (seven years) were used to parameterize the model. Simulations of ETo were compared to outputs from Ref-ET software, and simulated crop coefficients were contrasted among three crop coefficient methods: the current approach (Kcs), a previously published adjustment to the model’s Kc equation (Kcd), and a new dual Kc approach that follows FAO-56 explicitly (Kcb). Results showed that crop coefficient simulations with the new ETo-Kcb method better mimicked theoretical behavior, including spikes in the soil evaporation coefficient (Ke) due to irrigation and rainfall events and basal crop coefficient response as associated with simulated crop growth. Simulated ETc and yield with the new ETo-Kcb method were up to 4% higher and 28% lower for cotton and up to 13% higher and 26% lower for maize, respectively, than that with the current ETo-Kcs method, indicating that the seasonal ETc effects were minimal while yield effects were more substantial. Use of FAO-56 concepts and current ET standards in DSSAT-CSM demonstrated a well-accepted ET benchmark to guide assessment of other ET methods in the model and made the model much more conceptually relevant to irrigation and ET specialists. Keywords: Cotton, DSSAT, Evaporation, Evapotranspiration, FAO-56, Maize, Reference crop ET, Standardization, Transpiration.


2003 ◽  
Vol 60 (3) ◽  
pp. 595-599 ◽  
Author(s):  
Diniz Fronza ◽  
Marcos Vinícius Folegatti

The knowledge of water requirement of crops in the different growing phases elicits higher crop yield and rational use of water resource. The aim of this work was to estimate the water consumption of stevia using two constant watertable microlysimeters. The research was conducted in San Piero a Grado, Pisa, Italy. The data were collected daily from June, 1st, to October, 22th, 2000. Reference evapotranspiration was determined by the Penman-Monteith-FAO method, in the same period. Microlysimeters watertables level were maintained at the 35 cm depth. Crop evapotranspiration for the total cicle (80 days) was 464 mm. For the most water consuming phase, crop average evapotranspiration was 5.44 mm day-1. The crop coefficient values were 1.45 for the first 25 days, 1.14 for the next period (26 to 50 days), and 1.16 for the latest period (51 to 80 days). The stevia leaf yield of the microlysimeters was 4.369 kg ha-1 and their steviosideo content 6.49%.


Author(s):  
W. L. Miranda ◽  
L. G. Carvalho ◽  
P. Castro Neto ◽  
P. A. B. Santos

<p>A cultura da mamona é considerada resistente a deficiências hídricas, no entanto, apresenta considerável incremento de produtividade quando submetida à irrigação. Para o adequado manejo da irrigação um dos critérios passíveis de serem adotados baseia-se na evapotranspiração da cultura (ETc) e para tanto torna-se necessário o conhecimento do valor do coeficiente de cultura (Kc). Com o presente trabalho objetivou-se determinar o Kc da mamoneira em plantio adensado, no período de safrinha, utilizando-se lisímetro de drenagem. Foram utilizados três lisímetros de drenagem, com dimensões de 1,2 m de comprimento, 1,4 m de largura e 1,2 m de profundidade. Nos lisímetros foram plantadas oito mudas de mamoneira da cultivar Al Guarany 2002 com espaçamento de 0,3 m entre plantas e 0,7 m entre linhas. A ETc foi contabilizada no intervalo de 5 a 12 dias, conforme se observou o fim da drenagem. A evapotranspiração de referência (ETo) foi estimada pela equação de Penman-Monteith-FAO. A partir da relação ETc/ETo obteve-se o Kc para os diferentes períodos ao longo do ciclo da cultura. Os valores de ETc encontrados nas fases inicial, de crescimento, intermediária e final foram 1,65; 3,07; 9,14 e 5,85 mm d<sup>-1</sup> respectivamente. Os valores de Kc para as fases mencionadas foram 0,98; 1,41; 2,11 e 1,65 respectivamente.</p><p align="center"><strong><em>Use of drainage lysimeter for obtaining Kc of castor bean in dense plantation</em></strong></p><p><strong>Abstract</strong><strong>: </strong>Castor bean culture is considered resistant to water deficit. However, it presents considerable increase in productivity when submitted to irrigation. For the adequate irrigation management, one of the criterion considered is based on the crop evapotranspiration (ETc) and is necessary for finding the crop coefficient (Kc) value. With the present work, we aimed at determining the Kc of the castor bean in dense plantation, during the off-season, using a drainage lysimeter. Three drainage lysimeters, with dimensions of 1.2 m of length, 1.4 m of width and 1.2 m of depth, were used. In the lysimeters, eight castor bean seedlings, cultivar Al Guarany 2002 were planted with spacing of 0.3 m between plants and 0.7 m between lines.  The ETc was calculated considering the interval from 5 to 12 days, according to the end of drainage. The reference evapotranspiration (ETo) was estimated by the Penman-Monteith-FAO equation. From the ETc/ETo relation, we obtained the Kc for the different periods over the crop cycle. The ETc values found in the initial, growing, intermediate and final phases were of 1.65; 3.07; 9.14 and 5.85 mm d<sup>-</sup><sup>1</sup>, respectively. The Kc values for the mentioned phases were of 0.98; 1.41; 2.11 and 1.65, respectively.</p>


Author(s):  
Diego Fernando Daniel ◽  
Rivanildo Dallacort ◽  
João Danilo Barbieri ◽  
Marco Antônio Camillo de Carvalho ◽  
Santino Seabra Júnior ◽  
...  

The objective of this work was to determine the dual coefficient of culture (Kc) of maize in monoculture and intercropping systems, as well as to evaluate the influence of intercropping on evapotranspiration and productive characteristics of maize second season. The experiment was carried out in the experimental field of the State University of Mato Grosso - UNEMAT in 2018, with three treatments: T1 - maize monoculture; T2 - Crotalaria monoculture and T3 - maize + Crotalaria. The crop evapotranspiration (ETc) of maize, Crotalaria, and maize + Crotalaria intercropping was determined daily by weight variation of weighing lysimeters, converted into mm day-1. The methodology used was that of dual Kc - FAO 56, dividing the crop coefficient (Kc), in soil evaporation coefficient (Ke), determined in microlysimeters, and basal crop coefficient (Kcb), determined in weighing lysimeters. The phenological phases of the maize crop were observed to determine the coefficients in the different developmental stages, being the Kc, Kcb, Ke in the phases: Initial (I), Development (II), Intermediate (III) and Final (IV). The accumulated culture evapotranspiration was 312.00; 436.16 and 422.38 mm and daily averages of 2.86; 4.00- and 3.88-mm d-1, respectively for monoculture maize, for Crotalaria and for intercropping. The Kc values for each phase of maize development in intercropping with crotalaria were: I (1.46); II (1.48); III (1.59) and IV (0.94). For maize monoculture, dual Kc values were: I (1.24), II (1.30), III (1.00) and IV (1.11) and for Crotalaria monoculture were: I (1.77), II (1.59), III (1.56) and IV (1.05).


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