Measurements of the actual evapotranspiration and crop coefficients of summer and winter seasons crops in Japan

Attarod, Pedram; Aoki, Marcelo Saldanha; Bayramzadeh, Vilma

doi:10.17221/324-pse

Cited by 7 publications

(1 citation statement)

References 13 publications

(14 reference statements)

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“…Values of evapotranspiration (ET) rates vary widely in the literature. Attarod et al (2009) reported that average ET rates for the four vegetation seasons in the wheat, the soybean and the cornfield in the experimental farm of Tokyo University of Agriculture and Technology (Japan) were 2.4 mm day À1 , 3.6 mm day À1 and 3.5 mm day À1 , respectively. Daily ET rates varied from 4.3 mm day À1 at the winter wheat to 6.8 mm day À1 at the cornfield in the Fars province (Iran) (Shahrokhnia and Sepaskhah 2012).…”

Section: Discussionmentioning

confidence: 99%

Distribution of Solar Energy in Agriculture Landscape: Comparison Between Wet Meadow and Crops

Huryna

Hesslerová²,

Pokorný³

et al. 2014

The Role of Natural and Constructed Wetlands in Nutrient Cycling and Retention on the Landscape

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This study examines the impact of plant cover on water and energy exchange between land and atmosphere in the Třeboň Biosphere Reserve, Czech Republic. Energy fluxes, evapotranspiration and evaporative fraction were determined over typical crops of agriculture landscape and compared with fluxes in an adjacent wet meadow. The results show distinct differences in heat and water exchange between these ecosystems. Diurnal average difference in evapotranspiration rates for days with high irradiance over the wet meadow and arable crops ranged from 1.1 mm day À1 to 3.4 mm day À1 . Furthermore, the evapotranspiration differences between C3 (rapeseed) and C4 (cornfield) was about 2.3 mm day À1 . Analysis of thermovision pictures showed that temperature variation reached about 9 C between the ploughed field and meadows at the time of maximum intensity of solar radiation. Heat exchange (sensible heat flux) was greater over arable lands, while water exchange (latent heat flux) was stronger over the wet meadow. The evaporative fraction displayed that more than 100 % of available energy was released by the wet meadow through evapotranspiration due to the advection of dry air from the surroundings. Wetlands show equal or even inverse temperature in vertical profile, whereas corn and wheat show noticeable higher temperature at soil surface in comparison with plant stand surface. Therefore, we suggest that introduction of wetlands to agricultural land is one of the most important instruments for the management of water and heat balance of the landscape.

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Section: Discussionmentioning

confidence: 99%

Distribution of Solar Energy in Agriculture Landscape: Comparison Between Wet Meadow and Crops

Huryna

Hesslerová²,

Pokorný³

et al. 2014

The Role of Natural and Constructed Wetlands in Nutrient Cycling and Retention on the Landscape

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Actual and standard crop coefficients for semi-natural and planted grasslands and grasses: a review aimed at supporting water management to improve production and ecosystem services

et al. 2023

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Natural and planted grasslands play a very important role in agriculture as source of various ecosystem services, including carbon sequestration and biodiversity, and are responsible for a large fraction of agricultural water use in rainfed and irrigated fields. It is, therefore, relevant to precisely know their water use and vegetation requirements with consideration of relevant climate, from extremely cold, dry, with long winter seasons, to tropical humid and hot climates, thus with a large variability of vegetation. Semi-natural grasslands are basically used for grazing and mainly refer to highland pastures and meadows, steppes, savannas, pampas, and mixed forest systems. The FAO method to compute crop (vegetation) evapotranspiration (ETc) through the product of a crop coefficient (Kc) by the reference evapotranspiration (ETo) is adopted. The selected papers were those where actual ETc (ETc act) was derived from field observations and ETo was computed with the FAO56 definition, or with another method that could be referred to the former. Field derived ETc act methods included soil water balance, Bowen ratio and eddy covariance measurements, as well as remote sensing vegetation indices or surface energy balance models, thus reviewed Kc act (ETc act/ETo) values were obtained from field data. These Kc act refer to initial, mid-season and end season (Kc act ini, Kc act mid, Kc act end) when reported values were daily or monthly; otherwise, only average values (Kc act avg) were collected. For cases relative to cold or freezing winters, data refer to the warm season only. For grasses cut for hay, Kc act ini, Kc act mid, and Kc act end refer to a cut cycle. Kc act values rarely exceeded 1.25, thus indicating that field measurements reported did respect the available energy for evaporation. Overall, Kc act mid for semi-natural grasslands in cold climates were lower than those in hot climates except when available water was high, with Kc act mid for meadows and mountain pastures generally high. Steppes have Kc act mid values lower than savannas. Grasses commonly planted for hay and for landscape generally showed high Kc act mid values, while a larger variability was observed with grasses for grazing. The collected Kc act values were used to define standard Kc values for all grassland and grasses. Nevertheless, the tabulated Kc act are indicative values of Kc to be used for actual water management purposes and/or irrigation scheduling of planted grasslands. It is expected that a better knowledge of the standard and/or indicative Kc values for a wide variety of grasslands and grasses will support better management aimed to improve grass productivity and ecosystem services, including biodiversity and carbon sequestration.

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The role of water and vegetation in the distribution of solar energy and local climate: a review

Huryna¹,

Pokorný²

2016

Folia Geobot

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Measurements of the actual evapotranspiration and crop coefficients of summer and winter seasons crops in Japan

Cited by 7 publications

References 13 publications

Distribution of Solar Energy in Agriculture Landscape: Comparison Between Wet Meadow and Crops

Distribution of Solar Energy in Agriculture Landscape: Comparison Between Wet Meadow and Crops

Actual and standard crop coefficients for semi-natural and planted grasslands and grasses: a review aimed at supporting water management to improve production and ecosystem services

The role of water and vegetation in the distribution of solar energy and local climate: a review

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