Research on Assessment Method of Winter Wheat Water Use Efficiency Based on ET and Biomass with Remote Sensing

Author(s):  
Jun E. Fu ◽  
Zhiguo Pang ◽  
Jingxuan Lu
2021 ◽  
Vol 12 ◽  
Author(s):  
Hai-Yan Zhang ◽  
Meng-Ran Liu ◽  
Zi-Heng Feng ◽  
Li Song ◽  
Xiao Li ◽  
...  

Real-time non-destructive monitoring of water use efficiency (WUE) is important for screening high-yielding high-efficiency varieties and determining the rational allocation of water resources in winter wheat production. Compared with vertical observation angles, multi-angle remote sensing provides more information on mid to lower parts of the wheat canopy, thereby improving estimates of physical and chemical indicators of the entire canopy. In this study, multi-angle spectral reflectance and the WUE of the wheat canopy were obtained at different growth stages based on field experiments carried out across 4 years using three wheat varieties under different water and nitrogen fertilizer regimes. Using appropriate spectral parameters and sensitive observation angles, the quantitative relationships with wheat WUE were determined. The results revealed that backward observation angles were better than forward angles, while the common spectral parameters Lo and NDDAig were found to be closely related to WUE, although with increasing WUE, both parameters tended to become saturated. Using this data, we constructed a double-ratio vegetation index (NDDAig/FWBI), which we named the water efficiency index (WEI), reducing the impact of different test factors on the WUE monitoring model. As a result, we were able to create a unified monitoring model within an angle range of −20–10°. The equation fitting determination coefficient (R2) and root mean square error (RMSE) of the model were 0.623 and 0.406, respectively, while an independent experiment carried out to test the monitoring models confirmed that the model based on the new index was optimal, with R2, RMSE, and relative error (RE) values of 0.685, 0.473, and 11.847%, respectively. These findings suggest that the WEI is more sensitive to WUE changes than common spectral parameters, while also allowing wide-angle adaptation, which has important implications in parameter design and the configuration of satellite remote sensing and UAV sensors.


2021 ◽  
Vol 13 (12) ◽  
pp. 2393
Author(s):  
Wanyuan Cai ◽  
Sana Ullah ◽  
Lei Yan ◽  
Yi Lin

Water use efficiency (WUE) is a key index for understanding the ecosystem of carbon–water coupling. The undistinguishable carbon–water coupling mechanism and uncertainties of indirect methods by remote sensing products and process models render challenges for WUE remote sensing. In this paper, current progress in direct and indirect methods of WUE estimation by remote sensing is reviewed. Indirect methods based on gross primary production (GPP)/evapotranspiration (ET) from ground observation, processed models and remote sensing are the main ways to estimate WUE in which carbon and water cycles are independent processes. Various empirical models based on meteorological variables and remote sensed vegetation indices to estimate WUE proved the ability of remotely sensed data for WUE estimating. The analytical model provides a mechanistic opportunity for WUE estimation on an ecosystem scale, while the hypothesis has yet to be validated and applied for the shorter time scales. An optimized response of canopy conductance to atmospheric vapor pressure deficit (VPD) in an analytical model inverted from the conductance model has been also challenged. Partitioning transpiration (T) and evaporation (E) is a more complex phenomenon than that stated in the analytic model and needs a more precise remote sensing retrieval algorithm as well as ground validation, which is an opportunity for remote sensing to extrapolate WUE estimation from sites to a regional scale. Although studies on controlling the mechanism of environmental factors have provided an opportunity to improve WUE remote sensing, the mismatch in the spatial and temporal resolution of meteorological products and remote sensing data, as well as the uncertainty of meteorological reanalysis data, add further challenges. Therefore, improving the remote sensing-based methods of GPP and ET, developing high-quality meteorological forcing datasets and building mechanistic remote sensing models directly acting on carbon–water cycle coupling are possible ways to improve WUE remote sensing. Improvement in direct WUE remote sensing methods or remote sensing-driven ecosystem analysis methods can promote a better understanding of the global ecosystem carbon–water coupling mechanisms and vegetation functions–climate feedbacks to serve for the future global carbon neutrality.


Plant Disease ◽  
2010 ◽  
Vol 94 (6) ◽  
pp. 766-770 ◽  
Author(s):  
J. A. Price ◽  
F. Workneh ◽  
S. R. Evett ◽  
D. C. Jones ◽  
J. Arthur ◽  
...  

Greenhouse and field studies were conducted to determine the effects of Wheat streak mosaic virus (WSMV), a member of the family Potyviridae, on root development and water-use efficiency (WUE) of two hard red winter wheat (Triticum aestivum) cultivars, one susceptible and one resistant to WSMV. In the greenhouse studies, wheat cultivars were grown under three water regimes of 30, 60, and 80% soil saturation capacity. After inoculation with WSMV, plants were grown for approximately 4 weeks and then harvested. Root and shoot weights were measured to determine the effect of the disease on biomass. In all water treatments, root biomass and WUE of inoculated susceptible plants were significantly less (P < 0.05) than those of the noninoculated control plants. However, in the resistant cultivar, significance was only found in the 30 and 60% treatments for root weight and WUE, respectively. Field studies were also conducted under three water regimes based on reference evapotranspiration rates. Significant reductions in forage, grain yield, and crop WUE were observed in the inoculated susceptible plots compared with the noninoculated plots. Both studies demonstrated that wheat streak mosaic reduces WUE, which is a major concern in the Texas Panhandle because of limited availability of water.


2020 ◽  
Vol 242 ◽  
pp. 106410
Author(s):  
Yang Lu ◽  
Zongzheng Yan ◽  
Lu Li ◽  
Congshuai Gao ◽  
Liwei Shao

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1318 ◽  
Author(s):  
Zsuzsanna Farkas ◽  
Emese Varga-László ◽  
Angéla Anda ◽  
Ottó Veisz ◽  
Balázs Varga

The effects of simulated waterlogging, drought stress and their combination were examined in a model experiment in Martonvásár, Hungary, in 2018. Four modern winter wheat varieties (‘Mv Toborzó’ (TOB), ‘Mv Mambó’ (MAM), ‘Mv Karizma’ (KAR), ‘Mv Pálma’ (PAL)) and one old Hungarian winter wheat cultivar (‘Bánkúti 1201’ (BKT)) were tested. Apart from the control treatment (C), the plants were exposed to two different abiotic stresses. To simulate waterlogging (WL), plants were flooded at four leaf stage, while in the WL + D treatment, they were stressed both by waterlogging and by simulated drought stress at the early stage of plant development and at the heading stage, respectively. The waterlogging treatment resulted in a significant decrease in plant biomass (BKT, TOB), number of spikes (TOB), grain yield (BKT, TOB), water use (BTK) and water-use efficiency (TOB, MAM, PAL) compared to the controls. The combined treatment (WL + D) led to a significant decrease in plant height (BTK, MAM, KAR), number of spikes (BTK, TOB, MAM, KAR), thousand kernel weight (TOB), harvest index (BTK), biomass, grain yield, water-use efficiency (in all varieties) and water use (BKT, TOB, MAM, KAR) of the plants. The best water-use efficiency was observed for MAM; therefore, this genotype could be recommended for cultivation at stress prone areas. The varieties MAM, KAR and PAL also showed good adaptability.


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