A method for investigating the influence of soil water potential on yield and water use efficiency of some spring wheat cultivars

Author(s):  
C. Sommer ◽  
M. Schwarz
2005 ◽  
Vol 85 (4) ◽  
pp. 877-888 ◽  
Author(s):  
Paul G. Jefferson ◽  
Herb W. Cutforth

Crested wheatgrass (Agropyron cristatum L. Gaertn.) and alfalfa (Medicago sativa L.) are introduced forage species used for hay and grazing by cattle across western Canada. These species are well adapted to the semiarid region but their long-term responses to water stress have not been previously compared. Two alfalfa cultivars with contrasting root morphology (tap-rooted vs. creeping-rooted) and two crested wheatgrass (CWG) cultivars with different ploidy level (diploid vs. tetraploid) were compared with continuously cropped spring wheat (Triticum aestivum L.) for 6 yr at a semiarid location in western Canada. Soil water depletion, forage yield, water use efficiency, leaf water potential, osmotic potential and turgor were compared. There were no consistent differences between cultivars within alfalfa or CWG for variables measured. However, these two species exhibit different water stress response strategies. Leaf water potential of CWG was lower during midday stress period than that of alfalfa or wheat. Alfalfa apparently had greater capacity to osmotically adjust to avoid midday water stress and maintain higher turgor. Soil water use patterns changed as the stands aged. In the initial years of the trial, forage crops used soil water from upper layers of the profile. In later years, soil water was depleted down to 3 m by alfalfa and to 2 m by crested wheatgrass. Alfalfa was able to deplete soil water to lower concentrations than crested wheatgrass or wheat. Soil water depletion by wheat during the non-active growth season (after harvest to fall freeze-up) was much less than for CWG or alfalfa as expected for annual vs. perennial crops. As a result, more soil water was available to wheat during its active growth period. In the last 3 yr, the three species depleted all available soil water. Forage yield responses also changed over time. In the initial 3 yr, crested wheatgrass yielded as much as or more than alfalfa. For the last 3 yr of the experiment, alfalfa yielded more forage than crested wheatgrass. Forage crops deplete much more soil water during periods of aboveground growth dormancy than wheat. Water use efficiency of crested wheatgrass declined with stand age compared with fertilized continuous spring wheat. Alfalfa exhibited deep soil water extraction and apparent osmotic adjustment in response to water stress while CWG exhibited tolerance of low water potential during stress. Key words: forage yield, soil water, water potential, water use, water use efficiency, drought


2010 ◽  
Vol 90 (4) ◽  
pp. 489-497 ◽  
Author(s):  
H W Cutforth ◽  
P G Jefferson ◽  
C A Campbell ◽  
R H Ljunggren

In the semiarid prairie of western Canada, there is renewed interest for including short durations (≤3 yr) of perennial forage in rotations with annual crops. However, there are producers who want to grow longer durations (≥4 yr) of perennial forages in rotational systems. Therefore, we assessed spring wheat (Triticum aestivum L.) yield, grain protein, and water use efficiency following 6 yr of either crested wheatgrass [Agropyron cristatum (L.) Gaertn.], or alfalfa (Medicago sativa L.), or wheat, and then 1 yr of fallow. Yield, water use, and water use efficiency were significantly lower in the first year of spring wheat production (2000) when the prior crop was crested wheatgrass or alfalfa than when it was wheat. In the second year (2001), which was a near record drought year, wheat yield and water use were significantly lower when the prior crop was alfalfa than when it was grass or wheat. From 2002 to 2005, there were no consistent differences in water use, water use efficiency, or yield of wheat due to the prior perennial crop. Wheat grain protein concentration was significantly higher following alfalfa compared with following crested wheatgrass or continuous spring wheat from 2000 to 2005. This effect was attributed to the higher N-supplying power of the soil following alfalfa. Soil water content below the rooting depth of most annual crops (≥120 cm depth) was reduced by the prior alfalfa crop, and there was no evidence from 2000 to 2005 that soil water recharge was occurring below the 150-cm depth. Key words: Semiarid prairie, alfalfa, grass, spring wheat, yield, protein, water use


1997 ◽  
Vol 77 (1) ◽  
pp. 83-90 ◽  
Author(s):  
B. G. McConkey ◽  
D. J. Ulrich ◽  
F. B. Dyck

A study was conducted on a 4-m-high ridge in southwestern Saskatchewan to determine the relationship of slope position with the soil water regime and spring wheat (Triticumaestivum L.) production and to determine if those relationships were altered by subsoiling. In all years, available soil water in the spring to 120 cm increased significantly with distance upslope. This pattern was attributed to residual subsoil water in the rooting zone that had not been used by previous crops in a long-term crop-fallow rotation. After 3 yr of annual spring wheat production, soil water to 1.2 m at all slope positions approximately equalled the water content wilting point (4.0 MPa) water content, showing this residual water had been largely consumed. Apparent use of soil water between seeding and harvest at the upper slope positions was equal to or greater than that at the lower slope positions. Over-winter soil water conservation, using tall (≥ 30-cm-high) wheat stubble for snow trapping, at the upper slope positions was equal to or greater than that at the lower slope positions. In the non-drought years of 1987 and 1989, wheat yields and crop water use efficiency increased significantly with distance downslope. Since these slope effects were not related to water use or availability, they were attributed to higher soil productivity, probably related to more historical net erosion with distance upslope. During the drought year of 1988, wheat yields and water use efficiency were greatest at the upslope positions, but these results were confounded by uneven crop emergence. Subsoiling to 35 cm or deeper increased the amount and depth of infiltration of water in years with near-average November–April precipitation. Subsoiling had little effect on wheat yields and no effect on crop water use. Key words: Landscape, wheat, productivity, soil moisture


2014 ◽  
Vol 651-653 ◽  
pp. 1423-1431
Author(s):  
Hua Bing Ma ◽  
Mei Mei Li ◽  
Jun Jie Ren ◽  
Bao Guo Li ◽  
Guo Hui Qi

Objective : To provide scientific guidance for water management of precocious walnuts. Method: With 8 years old ‘Lvling’ walnut trees as samples, 5 irrigation quantity treatments were designed, including 0, 15, 30, 45 and 60 kg of water per plant for each time, respectively and the routine irrigation amount (CK) was 600 kg of water per plant for each time. During the draught stage in growing season, 3 times of irrigation were carried out, and the effects of different treatments on sap flow, water use efficiency, yield and fruit quality were compared. Results: The daily instantaneous maximum average sap flow rates were found with 60 kg of water and control; the daily highest average water use efficiency was 1.54 mmol/mol with the treatment of 30 kg water; the daily highest average leaf water potential was-1.23 MPa with control; the highest yield per plant (1.48 kg) was found with the control, and the yield of 45 kg and 60 kg water per plant one time accounted for 98.65% and 99.32% of that of control, respectively. with T1 the yield was the lowest, only accounting for 70.65% of the control. Conclusion: As the soil water contents increased, the diurnal variation curve of sap flow rates changed from unimodal to bimodal patterns in sunny days, the main peak was narrowed; the curve of diurnal variation of leaf water potential changed from "V" to "W" type; the leaf water use efficiency increased initially and then decreased later; and the nut quality was improved and the yield increased. The optimal soil water content (SWC) of 'Lvling' precocious walnuts ranged from 20.01% ~ 21.96%.


2016 ◽  
Vol 46 (7) ◽  
pp. 1145-1150 ◽  
Author(s):  
Daniel Fonseca de Carvalho ◽  
Dionizio Honório de Oliveira Neto ◽  
Luiz Fernando Felix ◽  
José Guilherme Marinho Guerra ◽  
Conan Ayade Salvador

ABSTRACT: The aim of the present study was to evaluate the effect of different irrigation depths on the yield, water use efficiency (WUE), and yield response factor (Ky) of carrot (cv. 'Brasília') in the edaphoclimatic conditions of Baixada Fluminense, RJ, Brazil. Field trials were conducted in a Red-Yellow Argisol in the 2010-2011period. A randomized block design was used, with 5 treatments (depths) and 4 replicates. Depths were applied by drippers with different flow rates, and the irrigation was managed by time domain reflectometry (TDR) technique. The reference (ETo) and crop (ETc) evapotranspiration depths reached 286.3 and 264.1mm in 2010, and 336.0 and 329.9mm in 2011, respectively. The root yield varied from 30.4 to 68.9t ha-1 as a response to treatments without irrigation and 100% replacement of the soil water depth, respectively. Values for WUE in the carrot crop varied from 15 to 31kg m-3 and the mean Ky value was 0.82. The mean values for Kc were obtained in the initial (0.76), intermediate (1.02), and final (0.96) stages. Carrot crop was influenced by different water depths (treatments) applied, and the highest value for WUE was obtained for 63.4% of soil water replacement.


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