scholarly journals Ecosystem Water Use Efficiency in the Three-North Region of China Based on Long-Term Satellite Data

2021 ◽  
Vol 13 (14) ◽  
pp. 7977
Author(s):  
Qi’ao Zhang ◽  
Wei Chen

Water use efficiency (WUE), given by the ratio between organic matter production and water consumption, could be considered as a very important ecological indicator for assessing vegetation system growth conditions by combining organic matter production and water consumption. It is especially important for regional vegetation sustainable management by creating enough organic matter with restricted water supply. Furthermore, proper analysis of WUE is vital for the evaluation and future plans of ecological restoration projects in ecologically fragile regions such as the Three-North region of China. In this study, ecosystem WUE across the Three-North region of China from 2001 to 2017 was obtained, and the variation trends and major influencing factors were also analyzed. The results demonstrated that (1) the average WUE across the Three-North region of China is 0.7376 g∙C∙m−2∙mm−1 with an annual increase of 0.002 g∙C∙m−2∙mm−1∙y−1; (2) the spatiotemporal variation trends of WUE are similar to those of gross primary production (GPP); and (3) in the southeastern parts of the Three-North region, the vegetation conditions are better with sustainable improvements, while in Xinjiang Province, the sustainable degradation areas are widely spread. The results of this research reveal large spatial heterogeneity of WUE, with high WUE mainly in the southeastern region with sufficient precipitation and afforestation programs. For those areas far away from this region, WUE is not satisfactory, suggesting that, for a sustainable vegetation growth, it is important to consider the water supply to maintain suitable vegetation cover. Furthermore, the results of this research are important for future ecological restoration and sustainable management of environment.

2014 ◽  
Vol 62 (7) ◽  
pp. 558 ◽  
Author(s):  
John Turner ◽  
Marcia J. Lambert

Alternative indices to use for nutrient use efficiency (NUE) were analysed for nitrogen, phosphorus, potassium, calcium, magnesium and sulfur, using 17 Eucalyptus pilularis forest sites to test the hypothesis that NUE increases with decreasing nutrient availability. Reported indices represent different measures of nutrient use, including (1) efficiency of acquisition from soil, (2) quantities required for organic matter production, (3) organic matter production related to uptake, (4) ability to internally retranslocate nutrients and (5) physiological requirement of nutrients. Some indices are highly correlated but the highest correlations were according to age. Phosphorus, the main growth-limiting nutrient, on average, produced 6.5 and 10.9 t of organic matter per kilogram of phosphorus required and taken up from soil, respectively. Comparable estimates were made for other nutrients. NUEs of mobile nutrients increased with decreases in nutrient availability and this supported the hypotheses when age was taken into account. The NUEs of one nutrient are not independent of other nutrients. The inverse of foliage nutrient concentration is a valuable low-cost index of nutrient utilisation and correlates with net primary production/nutrient requirement, and is related to age. Resorption of nutrients, comparing new and abscised tissue, was of low value, but abscised-tissue nutrient correlations are related to a lower benchmark and are of value. The use of selected NUE indices for species comparison was discussed.


2002 ◽  
Vol 53 (2) ◽  
pp. 201 ◽  
Author(s):  
L. Dalla Costa ◽  
G. Gianquinto

Lysimeters of size 1.5 by 1.5 by 1.5 m, containing a loamy soil, were used to study the effects of both water stress during the reproductive stage and underground water supply on bell pepper (Capsicum annuum L.). Continuous water stress treatments were obtained providing irrigation equal to 40%, 50%, 60%, 80%, and 120% of maximum evapotranspiration (ET), evenly applied from flowering to end of the season. Another set of treatments involved a transient drought stress imposed by withholding 80 mm of irrigation, based on ET, beginning at 2 growth stages (early fruit set, or mid fruit growth). A well-watered control (irrigated restoring the entire ET) was included for comparison. The underground water supply treatments involved 3 permanent watertable depths (0.40, 0.70, and 1.10 m below soil surface) and one variable depth increasing from 0.40 to 1.30 m. Continuous water stress significantly reduced total fresh weight of fruit, which was linearly related to the water consumption. The highest marketable yield was found at irrigation of 120% ET; the lowest at 40% ET. Marketable yield did not differ among 60%, 80%, and 100% ET. Withholding water during early fruit set restricted fruit yield significantly, whereas plants undergoing drought later in fruit growth yielded as well as the well-watered control. Total fruit yield with a shallow watertable (0.40 m depth) was comparable to above-ground irrigation restoring 100% ET, but marketable yield was significantly reduced. Highest marketable yield was obtained with watertable at 0.7 m depth, but was reduced by lowering watertable depth. The lower yield observed in water shortage conditions was generally due to a reduced fruit number. In most cases, water use efficiency decreased with increasing water consumption, but was not affected by transient drought stress. Crop nitrogen content was the highest when irrigation provided 100% and 120% ET restoration. It was significantly reduced only by both 40% ET and watertable irrigated treatments. Generally, a shallow watertable allowed less nitrogen rescue than a deeper one. The critical period for water was identified between the beginning of fruit set and first maturing fruits when soil water potential should be maintained above –0.02 MPa.


Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 602
Author(s):  
Stavroula Tsitsifli ◽  
Anastasia Papadopoulou ◽  
Vasilis Kanakoudis ◽  
Konstantinos Gonelas

Water use efficiency is a crucial issue in drinking water utilities as it is connected to environmental and economic consequences. WATenERgy CYCLE project aims at developing a methodological approach towards efficient and effective transnational water and energy resources management in the Balkan–Mediterranean area. The paper presents the results of performance evaluation of the water supply systems of the water utilities involved in the project, both at local and national level. The methodology used in the water balance and performance indicators as well as data on the operational status of the water supply systems. The results showed that Non-Revenue Water is one of the major problems addressed.


2011 ◽  
Vol 59 (1) ◽  
pp. 13-22
Author(s):  
Z. Varga-Haszonits ◽  
E. Enzsölné Gerencsér ◽  
Z. Lantos ◽  
Z. Varga

The temporal and spatial variability of soil moisture, evapotranspiration and water use were investigated for winter barley. Evaluations were carried out on a database containing meteorological and yield data from 15 stations. The spatial distribution of soil moisture, evapotranspiration and water use efficiency (WUE) was evaluated from 1951 to 2000 and the moisture conditions during the growth period of winter barley were investigated. The water supply was found to be favourable, since the average values of soil moisture remained above the lower limit of favourable water content throughout the growth period, except for September–December and May–June. The actual evapotranspiration tended to be close to the potential evapotranspiration, so the water supplies were favourable throughout the vegetation period. The calculated values of WUE showed an increasing trend from 1960 to 1990, but the lower level of agricultural inputs caused a decline after 1990. The average values of WUE varied between 0.87 and 1.09 g/kg in different counties, with higher values in the northern part of the Great Hungarian Plain. The potential yield of winter barley can be calculated from the maximum value of WUE. Except in the cooler northern and western parts of the country, the potential yield of winter barley, based on the water supply, could exceed 10 t/ha.


Irriga ◽  
2018 ◽  
Vol 21 (2) ◽  
pp. 352
Author(s):  
HIPÓLITO MURGA-ORRILLO ◽  
WELLINGTON FARIAS ARAUJO ◽  
CARLOS ABANTO RODRIGUEZ ◽  
RICARDO MANUEL BARDALES LOZANO ◽  
ROBERTO TADASHI SAKAZAKI ◽  
...  

INFLUÊNCIA DA COBERTURA MORTA NA EVAPOTRANSPIRAÇÃO, COEFICIENTE DE CULTIVO E EFICIÊNCIA DE USO DE ÁGUA DO MILHO CULTIVADO EM CERRADO HIPÓLITO MURGA-ORRILLO1; WELLINGTON FARIAS ARAÚJO2; CARLOS ABANTO-RODRIGUEZ3; ROBERTO TADASHI SAKAZAKI4; RICARDO MANUEL BARDALES-LOZANO5 E ANA ROSA POLO-VARGAS6 1Engenheiro Agrônomo, Prof. Auxiliar, Universidad Nacional Autónoma de Chota, (UNACH), Jr. Gregorio Malca Nº 875- Campus Colpa Matara, Chota, Perú. [email protected] Agrônomo, Prof. Dr. Associado da UFRR/CCA, Boa Vista, RR. [email protected] Florestal, Investigador no Instituto de Investigaciones de la Amazonía Peruana, Carretera Federico Basadre, Km 12,400, Yarinacocha, Ucayali, Perú. [email protected] Agrônomo, Doutorando na UFRR/CCA, Boa Vista, RR. [email protected] Agrônomo, Doutorando na UFRR/Bionorte, Boa Vista, RR. [email protected] Agrônoma, Graduada na Universidad Nacional de Cajamarca, (UNC), Av. Atahualpa Nº 1050- Carretera Cajamarca-Baños del Inca, Cajamarca, Perú. [email protected]  1 RESUMOA irrigação consome grande quantidade de água, sendo importante um adequado manejo da cultura para minimizar esse consumo, maximizando a produção. No intuito de obter informações para o manejo da irrigação, objetivou-se com o presente trabalho determinar a evapotranspiração da cultura (ETc), o coeficiente de cultivo (Kc) e a eficiência do uso de água (EUAg) da cultura de milho, em solo com e sem cobertura, durante os diferentes estádios de desenvolvimento, utilizando lisímetros de drenagem. O experimento foi conduzido no campus Cauamé da Universidade Federal de Roraima, entre 19/04/2014 e 07/08/2014, em Boa Vista, RR. A evapotranspiração de referência (ETo) foi estimada pelo método de Penman-Monteith FAO. Os resultados da ETc do milho, durante o ciclo da cultura, em solo sem e com cobertura foram de 421,5 e 351,0 mm, respectivamente. As médias diárias de ETc foram de 4,1 mm dia-1 para solo sem cobertura e 3,4 mm dia-1 para solo com cobertura. A cobertura do solo propiciou valores diferentes de Kc's para o milho, nos mesmos estádios, em comparação aos Kc’s do solo descoberto. Para o solo descoberto, os Kc’s observados para os estádios fenológicos I, II, III, e IV, foram de 0,40; 0,84; 1,59 e 0,81, respectivamente. Já para solo com cobertura, os Kc’s pelos mesmos estádios em menção foram 0,28; 0,64; 1,49 e 0,48, respectivamente. A EUAg para solo com cobertura foi 1,77 kg m-3 e para solo sem cobertura foi 1,65 kg m-3. Estes resultados mostram que a cobertura morta no solo influenciou no consumo hídrico do milho durante todo seu ciclo. Palavras-chave: Zea mays. Irrigação. Solo coberto. Consumo hídrico.  MURGA-ORRILLO, H.; ARAÚJO, W. F.; ABANTO-RODRIGUEZ C.; SAKAZAKI, R. T.; BARDALES-LOZANO R. M.; POLO-VARGAS, A. R.MULCH INFLUENCE ON EVAPOTRANSPIRATION, CROP COEFFICIENT AND WATER USE EFFICIENCY OF CORN GROWN IN THE SAVANNAH   2 ABSTRACTIrrigation consumes large amounts of water, and minimizing consumption and maximizing the production are  important to a proper crop management . In order to obtain information for irrigation management, the aim of the present study was to determine evapotranspiration (ETc),  crop coefficient (Kc) and  water use efficiency (WUE) of maize grown in soil with and without cover, during the various stages of development, using drainage lysimeters. The experiment was conducted in Cauamé campus of the Federal University of Roraima, from 19/04/2014 to 08/07/2014, in Boa Vista, RR. The reference evapotranspiration (ETo) was estimated by the Penman-Monteith method. The results of the corn ETc during the crop cycle in soil with and without coverage were 421.5 and 351.0 mm, respectively. The daily average of ETc were 4.1 mm day-1 for bare soil and 3.4 mm day-1 for soil with cover. The ground cover led to different values of Kc's for corn in the same stages as compared to Kc's from the bare ground. For bare soil, the Kc's observed for the phenological stages I, II, III, and IV were 0.40; 0.84; 1.59 and 0.81, respectively. As for covered soil, the Kc's in the same stadiums mentioned were 0.28; 0.64; 1.49 and 0.48, respectively. The WUE to soil with cover was 1.77 kg m-3 and ground without cover was 1.65 kg m-3. These results show that  soil mulching influenceS maize water consumption throughout its cycle. Keywords: Zea mays. Irrigation. Ground covered. Water consumption.


1970 ◽  
Vol 83 (990) ◽  
pp. 397-410 ◽  
Author(s):  
Masayuki TAKAHASHI ◽  
Yukuya YAMAGUCHI ◽  
Shun-ei ICHIMURA

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