Pre-sowing static magnetic field treatment for improving water and radiation use efficiency in chickpea (Cicer arietinumL.) under soil moisture stress

2016 ◽  
Vol 37 (6) ◽  
pp. 400-408 ◽  
Author(s):  
Nilimesh Mridha ◽  
Sudipta Chattaraj ◽  
Debashis Chakraborty ◽  
Anjali Anand ◽  
Pramila Aggarwal ◽  
...  
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.


1993 ◽  
Vol 44 (6) ◽  
pp. 1351 ◽  
Author(s):  
PJ Goyne ◽  
SP Milroy ◽  
JM Lilley ◽  
JM Hare

Dry matter production and utilization of photosynthetically active radiation (PAR) was studied for barley (Hordeurn vulgare L.) in the field at Hermitage Research Station, Qld. In 1990, four cultivars (Gilbert, Tallon, Grimmett, Skiff) were sown at three times and grown with non-limiting soil moisture. In 1991, soil moisture limitations were imposed on one sowing of the cultivar Grimmett. The radiation extinction coefficient (k) was 0.41�0.02 and did not vary with cultivar, time of sowing or soil moisture availability. Radiation use efficiency (RUE) (based on absorbed PAR and above-ground dry matter) did not change with time of sowing but did vary between cultivars. RUE was highest for Gilbert (2.90�0.10 g MJ-1), while the other three cultivars averaged 2.60�0.04 g MJ-l. RUE of Grimmett was significantly lower in 1991 (1.48�0.07 g MJ-1) than in 1990 (2.60�0.07g MJ-1), but soil moisture differences in 1991 did not significantly affect RUE. Several factors with possible links with RUE were examined and discussed. Of the variables examined those which showed the strongest relationships with RUE were average daily vapour pressure deficit and average daily minimum temperature.


2001 ◽  
Vol 52 (1) ◽  
pp. 103 ◽  
Author(s):  
P. J. Stone ◽  
D. R. Wilson ◽  
J. B. Reid ◽  
R. N. Gillespie

The responses of sweet corn biomass and yield to timing and severity of water deficit were determined in an experiment using a mobile rainshelter. Six irrigation treatments were applied such that plots experienced: (1) no water deficit; (2) full water deficit; (3) moderate pre-silking deficit; (4) severe pre-silking deficit; (5) moderate post-silking deficit; or (6) severe post-silking deficit. Drought was quantified using the concept of potential soil moisture deficit, which was calculated from climatic data. Potential soil moisture deficit can be related simply to a wide range of plant performance variables, making it possible to compare the relative importance of variables in determining the overall response of the crop to drought. For all treatments, yield was related strongly to biomass, especially that accumulated after silking. Biomass, in turn, was reduced by water deficit, mainly because of reduced radiation use efficiency, but also because of reduced total radiation interception, particularly in early deficit treatments. Both water use efficiency and transpiration efficiency increased with water deficit, even though soil evaporation as a proportion of total water use also increased with deficit. There was no stage of crop development at which yield was particularly sensitive to water deficit, although yield components changed with timing of deficit. Importantly, measures of potential soil moisture deficit integrated the effects of timing and severity of drought, making it possible to simply and mechanistically account for the effects of water deficit on biomass and particularly yield.


2021 ◽  
Vol 13 (4) ◽  
pp. 773
Author(s):  
Hadi Jaafar ◽  
Roya Mourad

In this study, we used Landsat Earth observations and gridded weather data along with global soil datasets available in Google Earth Engine (GEE) to estimate crop yield at 30 m resolution. We implemented a remote sensing and evapotranspiration-based light use efficiency model globally and integrated abiotic environmental stressors (temperature, soil moisture, and vapor deficit stressors). The operational model (Global Yield Mapper in Earth Engine (GYMEE)) was validated against actual yield data for three agricultural schemes with different climatic, soil, and management conditions located in Lebanon, Brazil, and Spain. Field-level crop yield data on wheat, potato, and corn for 2015–2020 were used for assessment. The performance of GYMEE was statistically evaluated through root-mean-square error (RMSE), mean absolute error (MAE), mean bias error (MBE), relative error (RE), and index of agreement (d). The results showed that the absolute difference between the modeled and predicted field-level yield was within ±16% for the analyzed crops in both Brazil and Lebanon study sites and within ±15% in the Spain site (except for two fields). GYMEE performed best for wheat crop in Lebanon with a low RMSE (0.6 t/ha), MAE (0.5 t/ha), MBE (−0.06 t/ha), and RE (0.83%). A very good agreement was observed for all analyzed crop yields, with an index of agreement (d) averaging at 0.8 in all studied sites. GYMEE shows potential in providing yield estimates for potato, wheat, and corn yields at a relative error of ±6%. We also quantified and spatialized the soil moisture stress constraint and its impact on reducing biomass production. A showcasing of moisture stress impact on two emphasized fields from the Lebanon site revealed that a 12% difference in soil moisture stress can decrease yield by 17%. A comparison between the 2017 and 2018 seasons for the potato culture of Lebanon showed that the 2017 season with lower abiotic stresses had higher light use efficiency, above-ground biomass, and yield by 5%, 10%, and 9%, respectively. The results show that the model is of high value for assessing global food production.


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.


Helia ◽  
2001 ◽  
Vol 24 (35) ◽  
pp. 101-110 ◽  
Author(s):  
S. Sridhara ◽  
T.G. Prasad

SUMMARYA field experiment was conducted at Gandhi Krishi Vignana Kendra, University of Agricultural Sciences, Bangalore to study the effect of irrigation regimens on the biomass accumulation, canopy development, light interception and radiation use efficiency of sunflower. The treatments includes irrigating the plants at 0.4, 0.6, 0.8 and 1.0 cumulative pan evaporation. The results indicated that the aboveground biomass, canopy development, radiation interception and radiation use efficiency were influenced favorably by the irrigation regimens. Irrespective of the irrigation regimen, the radiation use efficiency of sunflower increased from 15 DAS to 75 DAS and then tended to decline. The decrease in RUE after anthesis is coupled with decrease in leaf nitrogen content. In general the RUE of sunflower ranged from 0.49 g MJ-1 to 1.84 g MJ-1 at different growth stages. The light transmission within the canopy increased exponentially with plant height and the canopy extension coefficient is found to be 0.8.


Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 351
Author(s):  
Adolfo Rosati ◽  
Damiano Marchionni ◽  
Dario Mantovani ◽  
Luigi Ponti ◽  
Franco Famiani

We quantified the photosynthetically active radiation (PAR) interception in a high-density (HD) and a super high-density (SHD) or hedgerow olive system, by measuring the PAR transmitted under the canopy along transects at increasing distance from the tree rows. Transmitted PAR was measured every minute, then cumulated over the day and the season. The frequencies of the different PAR levels occurring during the day were calculated. SHD intercepted significantly but slightly less overall PAR than HD (0.57 ± 0.002 vs. 0.62 ± 0.03 of the PAR incident above the canopy) but had a much greater spatial variability of transmitted PAR (0.21 under the tree row, up to 0.59 in the alley center), compared to HD (range: 0.34–0.43). This corresponded to greater variability in the frequencies of daily PAR values, with the more shaded positions receiving greater frequencies of low PAR values. The much lower PAR level under the tree row in SHD, compared to any position in HD, implies greater self-shading in lower-canopy layers, despite similar overall interception. Therefore, knowing overall PAR interception does not allow an understanding of differences in PAR distribution on the ground and within the canopy and their possible effects on canopy radiation use efficiency (RUE) and performance, between different architectural systems.


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