Alpine grassland water use efficiency based on annual precipitation, growing season precipitation and growing season evapotranspiration

2015 ◽  
Vol 39 (7) ◽  
pp. 649-660 ◽  
Author(s):  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Growing Season ◽  
Alpine Grassland ◽  
Annual Precipitation ◽  
Use Efficiency ◽  
Growing Season Precipitation

EFFECT OF SOIL PROFILE TYPE AND FERTILIZER ON MOISTURE USE BY WHEAT GROWN ON FALLOW OR STUBBLE LAND

1969 ◽  
Vol 49 (2) ◽  
pp. 189-197 ◽  
Author(s):  
E. de Jong ◽  
D. A. Rennie
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Soil Profile ◽  
Growing Season ◽  
Yield Functions ◽  
Use Efficiency ◽  
Lower Slope ◽  
Growing Season Precipitation ◽  
Upper Slope

Equations describing yield as a function of moisture use arc reported for fallow-seeded wheat for the years 1960 to 1965, inclusive, and for wheat seeded on stubble land from 1964 to 1967. In general, yields increased linearly with water use; second-degree functions did not greatly increase the correlation, but represent more realistic yield functions. The increase in yield per cm water used was larger on fallow than on stubble land, and increased with fertilization. Growing season precipitation ranged from 5 to 26 cm during the study period; the long-term average is 19 cm. Mean yields for unfertilized and fertilized fallow and stubble wheat were 1,500 and 1,860 kg/ha, and 1,340 and 1,720 kg/ha, respectively.Yield, water used, and water use efficiency varied somewhat, depending on whether the crop was grown on a knoll, upper slope, lower slope, or in depressional areas.

Estimating the water use efficiency of spring barley using crop models

2018 ◽  
Vol 156 (5) ◽  
pp. 628-644 ◽  
Author(s):  
E. Pohanková ◽  
P. Hlavinka ◽  
M. Orság ◽  
J. Takáč ◽  
K. C. Kersebaum ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Spring Barley ◽  
Growing Season ◽  
Above Ground Biomass ◽  
Grain Yields ◽  
Crop Models ◽  
Average Value ◽  
Ground Biomass ◽  
Use Efficiency

AbstractIn the current study, simulations by five crop models (WOFOST, CERES-Barley, HERMES, DAISY and AQUACROP) were compared for 7–12 growing seasons of spring barley (Hordeum vulgare) at three sites in the Czech Republic. The aims were to compare how various process-based crop models with different calculation approaches simulate different values of transpiration (Ta) and evapotranspiration (ET) based on the same input data and compare the outputs of these simulations with reference data. From the outputs of each model, the water use efficiency (WUE) from Ta (WUETa) and from actual ET (WUEETa) was calculated for grain yields and above-ground biomass yield. The results of the first part of the study show that the model with the Penman approach for calculating ET simulates lower actual ET (ETa) sums, at an average of 250 mm during the growing season, than other models, which use the Penman–Monteith approach and simulate 330 mm on average during the growing season. In the second part of the current study, WUE reference values in the range 1.9–2.4 kg/m3were calculated for spring barley and grain yield. Values of WUETa/WUEETacalculated from the outputs of individual models for grain yields and above-ground biomass yields ranged from 2.0/1.0 to 5.9/3.8 kg/m3with an average value of 3.2/2.0 kg/m3and from 3.9/2.1 to 10.5/6.8 kg/m3with an average value of 6.5/4.0 kg/m3, respectively. The results confirm that the average values of all models are nearest to actual values.

scholarly journals Evapotranspiration, crop coefficient and water use efficiency of coriander grown in tropical environment

2018 ◽  
Vol 36 (4) ◽  
pp. 446-452 ◽  
Author(s):  
Vicente de PR da Silva ◽  
Inajá Francisco de Sousa ◽  
Alexandra L Tavares ◽  
Thieres George F da Silva ◽  
Bernardo B da Silva ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Crop Production ◽  
Field Experiments ◽  
Growth Parameters ◽  
Crop Coefficient ◽  
Growing Season ◽  
Tropical Environment ◽  
Mean Values ◽  
Use Efficiency

ABSTRACT The water scarcity is expected to intensify in the future and irrigation becomes an essential component of crop production, especially in arid and semiarid regions, where the available water resources are limited. Four field experiments were carried out at tropical environment in Brazil in 2013 and 2014, in order to evaluate the effect of planting date on crop evapotranspiration (ETc), crop coefficient (Kc), growth parameters and water use efficiency (WUE) of coriander (Coriandrum sativum) plants. The planting dates occurred during winter, spring, summer and autumn growing seasons. ETc was obtained through the soil water balance method and the reference evapotranspiration (ETo) through the Penman-Monteith method, using data collected from an automatic weather station located close to the experimental area. The results of the research showed that the mean values of coriander ETc and Kc were 139.8 mm and 0.87, respectively. Coriander water demand is higher in the summer growing season and lower in the winter; however, its yield is higher in the autumn and lower in the winter. Coriander has higher yield and development of its growth variables in the autumn growing season. The results also indicated that the interannual climate variations had significant effects on most growth variables, as yield, ETc and Kc of coriander grown in tropical environment.

Influence of row spacing on water use and yield of rain-fed wheat (Triticum aestivum L.) in a no-till system with stubble retention

2010 ◽  
Vol 61 (11) ◽  
pp. 892 ◽  
Author(s):  
S. G. L. Kleemann ◽  
G. S. Gill
Keyword(s):  
Grain Yield ◽  
Water Use Efficiency ◽  
Water Use ◽  
Vegetative Growth ◽  
Growing Season ◽  
Light Interception ◽  
Row Spacing ◽  
Spike Density ◽  
Stubble Retention ◽  
Use Efficiency

A 3-year field study was undertaken to investigate the effect of row spacing on vegetative growth, grain yield and water-use efficiency of wheat. All 3 years of the study experienced 21–51% below-average rainfall for the growing season. Widening row spacing led to reduced biomass and tillers on per plant basis which could be related to the reduction in light interception by the wheat canopy in the wide rows which in turn could have reduced assimilate production. Reduction in vegetative growth in 54-cm rows translated into a significant reduction in grain yield which was strongly associated (r2 = 0.71) with the loss of spike density. The pattern of crop water use (evapotranspiration, ET) during the growing season was very similar for the three row-spacing treatments. However, there was some evidence for slightly lower ET (~5%) in 54-cm rows in two growing seasons. More importantly, there was no evidence for increased ET during the post-anthesis phase in wide rows as has been speculated by some researchers. Over the 3 years of the study, grain yield declined by 5–8% as row spacing increased from 18 to 36 cm and by a further 12–20% as row spacing increased from 36 to 54 cm. There was a consistent decline in water-use efficiency for grain (WUEG) with increasing row spacing over the 3 years. WUEG declined by 6–11% as crop spacing increased from 18 to 36 cm and declined further by 12–15% as row spacing increased to 54 cm. Lower light interception at wider row spacing could have reduced assimilate production by wheat as well as increased soil evaporation due to lower shading of the soil surface in more open canopies. Growers adopting wider row spacing on these relatively heavy textured soils are likely to experience some reduction in grain yield and WUEG. However, some growers may be prepared to accept a small yield penalty from intermediate row spacing as a trade-off for increased stubble retention and soil health.

scholarly journals Optimizing alfalfa productivity and persistence versus greenhouse gases fluxes in a continental arid region

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8738 ◽  
Author(s):  
Jiao Ning ◽  
Xiong Z. He ◽  
Fujiang Hou ◽  
Shanning Lou ◽  
Xianjiang Chen ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Arid Regions ◽  
Soil Property ◽  
Growing Season ◽  
Forage Yield ◽  
Stand Age ◽  
Use Efficiency ◽  
Ghg Fluxes

Alfalfa in China is mostly planted in the semi-arid or arid Northwest inland regions due to its ability to take up water from deep in the soil and to fix atmospheric N2 which reduces N fertilizer application. However, perennial alfalfa may deplete soil water due to uptake and thus aggravate soil desiccation. The objectives of this study were (1) to determine the alfalfa forage yield, soil property (soil temperature (ST), soil water content (SWC), soil organic carbon (SOC) and soil total nitrogen (STN)) and greenhouse gas (GHG: methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2)) emissions affected by alfalfa stand age and growing season, (2) to investigate the effects of soil property on GHG emissions, and (3) to optimize the alfalfa stand age by integrating the two standard criteria, the forage yield and water use efficiency, and the total GHG efflux (CO2-eq). This study was performed in alfalfa fields of different ages (2, 3, 5 and 7 year old) during the growing season (from April to October) in a typical salinized meadow with temperate continental arid climate in the Northwest inland regions, China. Despite its higher total GHG efflux (CO2-eq), the greater forage yield and water use efficiency with lower GEIhay and high CH4 uptake in the 5-year alfalfa stand suggested an optimal alfalfa stand age of 5 years. Results show that ST, SOC and RBM alone had positive effects (except RBM had no significant effect on CH4 effluxes), but SWC and STN alone had negative effects on GHG fluxes. Furthermore, results demonstrate that in arid regions SWC superseded ST, SOC, STN and RBM as a key factor regulating GHG fluxes, and soil water stress may have led to a net uptake of CH4 by soils and a reduction of N2O and CO2 effluxes from alfalfa fields. Our study has provided insights into the determination of alfalfa stand age and the understanding of mechanisms regulating GHG fluxes in alfalfa fields in the continental arid regions. This knowledge is essential to decide the alfalfa retention time by considering the hay yield, water use efficiency as well as GHG emission.

scholarly journals Water-Use Efficiency of Co-occurring Sky-Island Pine Species in the North American Great Basin

2021 ◽  
Vol 12 ◽  
Author(s):  
Xinsheng Liu ◽  
Emanuele Ziaco ◽  
Franco Biondi
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Growing Season ◽  
Stem Growth ◽  
Tree Level ◽  
Late Season ◽  
Limber Pine ◽  
Use Efficiency ◽  
Sky Island ◽  
The Impact

Water-use efficiency (WUE), weighing the balance between plant transpiration and growth, is a key characteristic of ecosystem functioning and a component of tree drought resistance. Seasonal dynamics of tree-level WUE and its connections with drought variability have not been previously explored in sky-island montane forests. We investigated whole-tree transpiration and stem growth of bristlecone (Pinus longaeva) and limber pine (Pinus flexilis) within a high-elevation stand in central-eastern Nevada, United States, using sub-hourly measurements over 5 years (2013–2017). A moderate drought was generally observed early in the growing season, whereas interannual variability of summer rains determined drought levels between years, i.e., reducing drought stress in 2013–2014 while enhancing it in 2015–2017. Transpiration and basal area increment (BAI) of both pines were coupled throughout June–July, resulting in a high but relatively constant early season WUE. In contrast, both pines showed high interannual plasticity in late-season WUE, with a predominant role of stem growth in driving WUE. Overall, bristlecone pine was characterized by a lower WUE compared to limber pine. Dry or wet episodes in the late growing season overrode species differences. Our results suggested thresholds of vapor pressure deficit and soil moisture that would lead to opposite responses of WUE to late-season dry or wet conditions. These findings provide novel insights and clarify potential mechanisms modulating tree-level WUE in sky-island ecosystems of semi-arid regions, thereby helping land managers to design appropriate science-based strategies and reduce uncertainties associated with the impact of future climatic changes.

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