Crop Coefficient (kc) and Water Use Efficiency (WUE) of Soybean as Affected by Soil Moisture Stress and Fertility Levels

2002 ◽  
Vol 2 (12) ◽  
pp. 1096-1098 ◽  
Author(s):  
U.A. Burriro . ◽  
H.A. Samoon . ◽  
F.C. Oad . ◽  
G.H. Jamro .
2014 ◽  
Vol 7 (5) ◽  
pp. 2193-2222 ◽  
Author(s):  
G. B. Bonan ◽  
M. Williams ◽  
R. A. Fisher ◽  
K. W. Oleson

Abstract. The Ball–Berry stomatal conductance model is commonly used in earth system models to simulate biotic regulation of evapotranspiration. However, the dependence of stomatal conductance (gs) on vapor pressure deficit (Ds) and soil moisture must be empirically parameterized. We evaluated the Ball–Berry model used in the Community Land Model version 4.5 (CLM4.5) and an alternative stomatal conductance model that links leaf gas exchange, plant hydraulic constraints, and the soil–plant–atmosphere continuum (SPA). The SPA model simulates stomatal conductance numerically by (1) optimizing photosynthetic carbon gain per unit water loss while (2) constraining stomatal opening to prevent leaf water potential from dropping below a critical minimum. We evaluated two optimization algorithms: intrinsic water-use efficiency (ΔAn /Δgs, the marginal carbon gain of stomatal opening) and water-use efficiency (ΔAn /ΔEl, the marginal carbon gain of transpiration water loss). We implemented the stomatal models in a multi-layer plant canopy model to resolve profiles of gas exchange, leaf water potential, and plant hydraulics within the canopy, and evaluated the simulations using leaf analyses, eddy covariance fluxes at six forest sites, and parameter sensitivity analyses. The primary differences among stomatal models relate to soil moisture stress and vapor pressure deficit responses. Without soil moisture stress, the performance of the SPA stomatal model was comparable to or slightly better than the CLM Ball–Berry model in flux tower simulations, but was significantly better than the CLM Ball–Berry model when there was soil moisture stress. Functional dependence of gs on soil moisture emerged from water flow along the soil-to-leaf pathway rather than being imposed a priori, as in the CLM Ball–Berry model. Similar functional dependence of gs on Ds emerged from the ΔAn/ΔEl optimization, but not the ΔAn /gs optimization. Two parameters (stomatal efficiency and root hydraulic conductivity) minimized errors with the SPA stomatal model. The critical stomatal efficiency for optimization (ι) gave results consistent with relationships between maximum An and gs seen in leaf trait data sets and is related to the slope (g1) of the Ball–Berry model. Root hydraulic conductivity (Rr*) was consistent with estimates from literature surveys. The two central concepts embodied in the SPA stomatal model, that plants account for both water-use efficiency and for hydraulic safety in regulating stomatal conductance, imply a notion of optimal plant strategies and provide testable model hypotheses, rather than empirical descriptions of plant behavior.


1962 ◽  
Vol 42 (1) ◽  
pp. 7-12 ◽  
Author(s):  
S. J. Bourget ◽  
R. B. Carson

Yields of oats and alfalfa grown in two soils in the greenhouse, with and without fertilizer, usually decreased with increasing moisture stress obtained by depleting the available moisture to 75, 50, 25 and nearly 0 per cent.An application of 6-20-20 fertilizer for oats and of 0-20-20 for alfalfa at the rate of 1000 pounds per acre gave a marked increase in crops yield and it resulted in a more efficient use of water by the crops than was obtained without fertilizer, although the total amount of water used was greater with than without fertilizer. The water-use efficiency values for oats usually increased with decreasing available water whereas those for alfalfa were less consistent.The composition in nitrogen, phosphorus, potassium, calcium and magnesium of the plant tissues did not vary greatly. However, the phosphorus content of oats grain decreased with increasing soil moisture stress unless fertilizer was added, indicating that soil phosphorus became less available for oats at high moisture stress.


2014 ◽  
Vol 7 (3) ◽  
pp. 3085-3159 ◽  
Author(s):  
G. B. Bonan ◽  
M. Williams ◽  
R. A. Fisher ◽  
K. W. Oleson

Abstract. The empirical Ball–Berry stomatal conductance model is commonly used in Earth system models to simulate biotic regulation of evapotranspiration. However, the dependence of stomatal conductance (gs) on vapor pressure deficit (Ds) and soil moisture must both be empirically parameterized. We evaluated the Ball–Berry model used in the Community Land Model version 4.5 (CLM4.5) and an alternative stomatal conductance model that links leaf gas exchange, plant hydraulic constraints, and the soil–plant–atmosphere continuum (SPA) to numerically optimize photosynthetic carbon gain per unit water loss while preventing leaf water potential dropping below a critical minimum level. We evaluated two alternative optimization algorithms: intrinsic water-use efficiency (Δ An/Δ gs, the marginal carbon gain of stomatal opening) and water-use efficiency (Δ An/Δ El, the marginal carbon gain of water loss). We implemented the stomatal models in a multi-layer plant canopy model, to resolve profiles of gas exchange, leaf water potential, and plant hydraulics within the canopy, and evaluated the simulations using: (1) leaf analyses; (2) canopy net radiation, sensible heat flux, latent heat flux, and gross primary production at six AmeriFlux sites spanning 51 site–years; and (3) parameter sensitivity analyses. Without soil moisture stress, the performance of the SPA stomatal conductance model was generally comparable to or somewhat better than the Ball–Berry model in flux tower simulations, but was significantly better than the Ball–Berry model when there was soil moisture stress. Functional dependence of gs on soil moisture emerged from the physiological theory linking leaf water-use efficiency and water flow to and from the leaf along the soil-to-leaf pathway rather than being imposed a priori, as in the Ball–Berry model. Similar functional dependence of gs on Ds emerged from the water-use efficiency optimization. Sensitivity analyses showed that two parameters (stomatal efficiency and root hydraulic conductivity) minimized errors with the SPA stomatal conductance model. The critical stomatal efficiency for optimization (ι) was estimated from leaf trait datasets and is related to the slope parameter (g1) of the Ball–Berry model. The optimized parameter value was consistent with this estimate. Optimized root hydraulic conductivity was consistent with estimates from literature surveys. The two central concepts embodied in the stomatal model, that plants account for both water-use efficiency and for hydraulic safety in regulating stomatal conductance, imply a notion of optimal plant strategies and provide testable model hypotheses, rather than empirical descriptions of plant behavior.


2014 ◽  
Vol 11 (2) ◽  
pp. 149-159 ◽  
Author(s):  
Raj Pal Meena ◽  
R Sendhil ◽  
SC Tripathi ◽  
Subhash Chander ◽  
RS Chhokar ◽  
...  

Wheat is the second most important staple food crop of India and contributes a major share to food basket of the country. Since majority of the area under wheat is irrigated, it consumes huge quantity of fresh water for its cultivation. The availability of good quality water for irrigation is decreasing over a period of time due to vagaries of monsoon, urbanization and industrialization. The biggest challenge on this front is to improve the efficiency and productivity of water being used in existing cropping system. Therefore, it is the need of hour to improve water use efficiency for wheat production. In the milieu, the present investigation was taken with an objective of studying the effect of pre-germinated seed in crop establishment under sub-optimal soil moisture conditions by using the residual soil moisture after harvesting of rice in Indo-Gangetic plains, so that pre sowing irrigation requirement for crop establishment may be cut and reduced in time period which require from pre-sowing irrigation to field preparation. This experiment was conducted for two consecutive years 2010-11 and 2011-12 to evaluate the influence of hydropriming on the water use efficiency and grain yield of wheat (Triticum aestivum L.) under moisture stress. The experiment was conducted in split plot design with three replications keeping moisture stress treatments (optimum moisture, sub-optimal moisture and dry soil followed by irrigation) in main plots and seed priming treatments (dry seed, hydropriming, and pre-germinated seeds) in subplots. Pregerminated seed produced significantly higher grain yield (5.49 t ha-1), which was statistically similar to hydropriming (5.30 t ha-1). Various seeding methods were statistically at par. The hydro-primed and pregerminated seeds established earlier than dry seeds leading to better crop establishment under optimum, sub optimum soil moisture as well as dry soil conditions leading to higher tillering and grain yield. The results of experiment showed that priming with plain water and pre-germinated seeds improved germination indices, seedling growth and crop establishment. Since priming with plain water and to have pregerminated seeds is simple and cheap method, which can increase germination percentage and homogeneity of seedling emergence under water stress conditions and it can be easily used by farmers. Interactive effect of different seed priming techniques along with seeding at sub optimal soil moisture level proved to be an efficient technique for enhancing water productivity of wheat crop. DOI: http://dx.doi.org/10.3329/sja.v11i2.18410 SAARC J. Agri., 11(2): 149-159 (2013)


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.


1972 ◽  
Vol 8 (2) ◽  
pp. 171-175 ◽  
Author(s):  
I. P. Abrol ◽  
S. P. Dixit

SUMMARYA comparison has been made of drip and conventional check basin methods of irrigation, using onions and ladies finger as test crops. Significant increases in yield and water use efficiency in drip irrigated over conventionally irrigated plots resulted from increased availability of soil moisture at low tensions and reduced surface evaporation losses. Reduced soil strength in drip irrigated plots was also a factor resulting in increased yield of onions.


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