The role of Evapotranspiration and Water Use Efficiency in Agriculture in Portugal

Growth Monitoring ◽

Climate Variability And Change ◽

Wine Production ◽

Understanding climate variability and change and its impacts on natural systems is becoming more and more important as changes in earth surface condition near surface air temperature and precipitation. Over Portugal, the observed warming trends have been found to be asymmetric with respect to seasonal and diurnal cycles, with greatest warming occurring for the minimum temperature and during winter and spring. These observed trends exert strong influences on agriculture systems, affecting production viability through changes in winter hardening, frost occurrence, growing season lengths and heat accumulation for ripening potential.Remote sensing technology has been developing steadily and its products can provide many applications in agriculture, namely crop identification, crop growth monitoring and yield prediction. Recently the LSA SAF team set up a strategy to generate long term data records from Meteosat Second Generation satellite series (2004 to present), releasing Land Surface Temperature (LST), Reference Evapotranspiration (ETREF) and Vegetation parameters (FAPAR, LAI and FVC) using a stable set of input data and algorithm, which would be suitable for climate variability and change detection studies. On the other hand, a new product to characterize the ecosystem processes, the&#160;Gross Primary Production (GPP), is under production since 2018.In this work we propose to computed Water Use Efficiency (WUE), as the ratio between Gross Primary Production (GPP) and Reference Evapotranspiration (ETREF), using LSA-SAF Products. WUE translates the exchanges of carbon and water gross fluxes, between natural ecosystem and the atmosphere, allowing to monitor the adaptability of the ecosystems to climate change. The role played by Evapotranspiration and Water Use Efficiency for different crops in Portugal is evaluated, namely on Wine Production for Douro Region. Results for 2018 and 2019 highlights the vulnerability of the different sectors of Douro Region to dry and wet conditions, namely helping to analyze the impact of droughts on Douro wine production.Acknowledgements: This study was performed within the framework of the LSA-SAF, co-funded by EUMETSAT This work was partially supported by national funds through FCT (Funda&#231;&#227;o para a Ci&#234;ncia e a Tecnologia, Portugal) under projects CLMALERT (ERA4CS/0005/2016).

Peer review report 1 On “Parameterizing ecosystem light use efficiency and water use efficiency to estimate maize gross primary production and evapotranspiration using MODIS EVI”

10.1016/j.agrformet.2016.11.016 ◽

2016 ◽

Vol 217 ◽

pp. 167

Author(s):

Alfredo R. Huete

Keyword(s):

Primary Production ◽

Water Use Efficiency ◽

Peer Review ◽

Water Use ◽

Light Use Efficiency ◽

Modis Evi ◽

Primary production in forests and grasslands of China: contrasting environmental responses of light- and water-use efficiency models

Biogeosciences Discussions ◽

10.5194/bgd-9-4285-2012 ◽

2012 ◽

Vol 9 (4) ◽

pp. 4285-4321 ◽

Cited By ~ 2

Author(s):

H. Wang ◽

I. C. Prentice ◽

J. Ni

Keyword(s):

Primary Production ◽

Water Use Efficiency ◽

Water Use ◽

South China ◽

Net Primary Production ◽

Stomatal Closure ◽

Co2 Response ◽

Data Set ◽

Abstract. An extensive data set on net primary production (NPP) in China's forests is analysed with two semi-empirical models based on the light use efficiency (LUE) and water use efficiency (WUE) concepts, respectively. Results are shown to be broadly consistent with other data sets (grassland above-ground NPP; globally extrapolated gross primary production, GPP) and published analyses. But although both models describe the data about equally well, they predict notably different responses to [CO2] and temperature. These are illustrated by sensitivity tests in which [CO2] is kept constant or doubled, temperatures are kept constant or increased by 3.5 K, and precipitation is changed by ±10%. Precipitation changes elicit similar responses in both models. The [CO2] response of the WUE model is much larger but is probably an overestimate for dense vegetation as it assumes no increase in runoff; while the [CO2] response of the LUE model is probably too small for sparse vegetation as it assumes no increase in vegetation cover. In the LUE model warming reduces total NPP with the strongest effect in South China, where the growing season cannot be further extended. In the WUE model warming increases total NPP, again with the strongest effect in South China, where abundant water supply precludes stomatal closure. The qualitative differences between the two formulations illustrate potential causes of the large differences (even in sign) in the global NPP response of dynamic global vegetation models to [CO2] and climate change. As it is not clear which response is more realistic, the issue needs to be resolved by observation and experiment.

Parameterizing ecosystem light use efficiency and water use efficiency to estimate maize gross primary production and evapotranspiration using MODIS EVI

10.1016/j.agrformet.2016.03.009 ◽

2016 ◽

Vol 222 ◽

pp. 87-97 ◽

Cited By ~ 30

Author(s):

Pradeep Wagle ◽

Prasanna H. Gowda ◽

Xiangming Xiao ◽

Anup KC

Keyword(s):

Primary Production ◽

Water Use Efficiency ◽

Water Use ◽

Light Use Efficiency ◽

Modis Evi ◽

Variation of gross primary production, evapotranspiration and water use efficiency for global croplands

10.1016/j.agrformet.2020.107935 ◽

2020 ◽

Vol 287 ◽

pp. 107935

Author(s):

Zhipin Ai ◽

Qinxue Wang ◽

Yonghui Yang ◽

Kiril Manevski ◽

Shuang Yi ◽

...

Keyword(s):

Primary Production ◽

Water Use Efficiency ◽

Water Use ◽

Peer review report 1 On “Parameterizing ecosystem light use efficiency and water use efficiency to estimate maize gross primary production and evapotranspiration using MODIS EVI”

10.1016/j.agrformet.2016.11.015 ◽

2016 ◽

Vol 217 ◽

pp. 172

Author(s):

Alfredo R. Huete

Keyword(s):

Primary Production ◽

Water Use Efficiency ◽

Peer Review ◽

Water Use ◽

Light Use Efficiency ◽

Modis Evi ◽

Calcium and Potassium Nutrition Increases the Water Use Efficiency in Coffee: A Promising Strategy to Adapt to Climate Change

Hydrology ◽

10.3390/hydrology8020075 ◽

2021 ◽

Vol 8 (2) ◽

pp. 75

Author(s):

Victor Hugo Ramírez-Builes ◽

Jürgen Küsters

Keyword(s):

Climate Change ◽

Climate Variability ◽

Water Use Efficiency ◽

Water Use ◽

Agricultural Sector ◽

Regional Scale ◽

Adaptation Strategies ◽

Caribbean Region ◽

Coffee Production ◽

Coffee (Coffea spp.) represents one of the most important sources of income and goods for the agricultural sector in Central America, Colombia, and the Caribbean region. The sustainability of coffee production at the global and regional scale is under threat by climate change, with a major risk of losing near to 50% of today’s suitable area for coffee by 2050. Rain-fed coffee production dominates in the region, and under increasing climate variability and climate change impacts, these production areas are under threat due to air temperature increase and changes in rainfall patterns and volumes. Identification, evaluation, and implementation of adaptation strategies for growers to cope with climate variability and change impacts are relevant and high priority. Incremental adaptation strategies, including proper soil and water management, contribute to improved water use efficiency (WUE) and should be the first line of action to adapt the coffee crop to the changing growing conditions. This research’s objective was to evaluate at field level over five years the influence of fertilization with calcium (Ca+2) and potassium (K+) on WUE in two coffee arabica varieties: cv. Castillo and cv. Caturra. Castillo has resistance against coffee leaf rust (CLR) (Hemileia vastatrix Verkeley and Brome), while Caturra is not CLR-resistant. WUE was influenced by yield changes during the years by climate variability due to El Niño–ENSO conditions and CLR incidence. Application of Ca+2 and K+ improved the WUE under such variable conditions. The highest WUE values were obtained with an application of 100 kg CaO ha−1 year−1 and between 180 to 230 kg K2O ha−1 year−1. The results indicate that adequate nutrition with Ca+2 and K+ can improve WUE in the long-term, even underwater deficit conditions and after the substantial incidence. Hence, an optimum application of Ca+2 and K+ in rain-fed coffee plantations can be regarded as an effective strategy to adapt to climate variability and climate change.

Irrigation management strategy for Prata-type banana

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v20n9p817-822 ◽

2016 ◽

Vol 20 (9) ◽

pp. 817-822 ◽

Cited By ~ 3

Author(s):

Marcelo R. dos Santos ◽

Sérgio L. R. Donato ◽

Lilian L. Lourenço ◽

Tânia S. Silva ◽

Mauricio A. Coelho Filho

Keyword(s):

Water Use Efficiency ◽

Water Use ◽

Management Strategy ◽

Reference Evapotranspiration ◽

Irrigation System ◽

Irrigation Management ◽

Crop Coefficient ◽

Mother And Daughter ◽

Production Cycles ◽

ABSTRACT This study aimed to analyze different irrigation strategies in two cultivars of the banana crop. The study was conducted in four production cycles of ‘Prata-Anã’ and ‘BRS Platina’ bananas. The applied irrigation depths (ID) were obtained by the model ID = K x LA x ETo, where K is an empirical transpiration constant of 0.20; 0.35; 0.50 and 0.65 for the strategies 1, 2, 3 and 4, respectively; LA is the leaf area of mother and daughter plants of ‘Prata-Anã’ and ETo is the reference evapotranspiration. The strategy 5 was obtained according to the crop evapotranspiration, ETc = ETo x Kc, where Kc is the crop coefficient. Drip irrigation system was used, with two laterals per plant row and emitters with flow rate of 8 L h-1, spaced at 0.50 m. It was found that ‘Prata-Anã’ is more efficient than ‘BRS Platina’ in terms of water use and the model for irrigation management, ID = 0.35 x LA x ETo, is recommended to optimize water use by ‘Prata-Anã’ and ‘BRS Platina’ bananas, with increase in water use efficiency and maintenance of yield. The same model, with K coefficient equal to 0.50, makes it possible to obtain yield and water use efficiency equal to those obtained with irrigation management based on the ETc.

Drought Enhances the Role of Competition in Mediating the Relationship between Tree Growth and Climate in Semi-Arid Areas of Northwest China

Forests ◽

10.3390/f10090804 ◽

2019 ◽

Vol 10 (9) ◽

pp. 804 ◽

Cited By ~ 3

Author(s):

Kanglong Lu ◽

Ning Chen ◽

Cankun Zhang ◽

Xiaoxue Dong ◽

Changming Zhao

Keyword(s):

Climate Variability ◽

Water Use Efficiency ◽

Water Use ◽

Tree Growth ◽

Radial Growth ◽

Intrinsic Water Use Efficiency ◽

Adverse Weather ◽

Significant Difference ◽

Use Efficiency ◽

The Relationship

Climate variability can exert a powerful impact on biotic competition, but past studies have focused largely on short-lived species, with a lack of attention to long-lived species such as trees. Therefore, there is a need to evaluate how competition regulates the climate-growth relationship in mature trees. We sampled the dominant tree species, Picea wilsonii Mast., on Xinglong Mountain, China, and studied the above issues by analyzing the relationship between tree radial growth, precipitation, and competition. In relatively wet years (precipitation > average), there was no significant difference in climate sensitivity between different competition classes. However, trees suffering from highly competitive stress were more sensitive to climate variability in all years, and particularly in the subset of years that was relatively drought (precipitation < average). These results suggest that competition enhances its ability to regulate tree growth response to climate variability in adverse weather conditions. Competition for resources between trees was asymmetrical, and an increase in height could give trees a disproportionate benefit. Thus, at trunk-level, both basal area incremental growth and intrinsic water-use efficiency of trees subjected to low competitive stress were significantly higher than trees that are subjected to highly competitive stress. Although the intrinsic water-use efficiency of trees under highly competitive stress increased more rapidly as the drought level increases, this did not change the fact that the radial growth of them declined more. Our research is valuable for the development of individual-tree growth models and advances our understanding for forest management under global climate change.

Primary production in forests and grasslands of China: contrasting environmental responses of light- and water-use efficiency models

Biogeosciences ◽

10.5194/bg-9-4689-2012 ◽

2012 ◽

Vol 9 (11) ◽

pp. 4689-4705 ◽

Cited By ~ 13

Author(s):

H. Wang ◽

I. C. Prentice ◽

J. Ni

Keyword(s):

Primary Production ◽

Water Use Efficiency ◽

Water Use ◽

Net Primary Production ◽

Upper And Lower Bounds ◽

Co2 Response ◽

Data Set ◽

Use Efficiency ◽

Vegetation Models ◽

Environmental Responses

Abstract. An extensive data set on net primary production (NPP) in China's forests is analysed with the help of two simple theoretically derived models based on the light use efficiency (LUE) and water use efficiency (WUE) concepts, respectively. The two models describe the data equally well, but their implied responses to [CO2] and temperature differ substantially. These responses are illustrated by sensitivity tests in which [CO2] is kept constant or doubled, temperatures are kept constant or increased by 3.5 K, and precipitation is changed by ±10%. Precipitation changes elicit similar responses in both models. But NPP in South China, especially, is reduced by warming in the LUE model, whereas it is increased in the WUE model. The [CO2] response of the WUE model is much larger than that of the LUE model. It is argued that the two models provide upper and lower bounds for this response, with the LUE model more realistic for forests. The differences between the two models illustrate some potential causes of the large differences (even in sign) in the global NPP response of different global vegetation models to temperature and [CO2].