Water use efficiency of spring wheat in the semi-arid Canadian prairies: Effect of legume green manure, type of spring wheat, and cropping frequency

2014 ◽  
Vol 94 (2) ◽  
pp. 223-235 ◽  
Author(s):  
R. Kröbel ◽  
R. Lemke ◽  
C. A. Campbell ◽  
R. Zentner ◽  
B. McConkey ◽  
...  

Kröbel, R., Lemke, R., Campbell, C. A., Zentner, R., McConkey, B., Steppuhn, H., De Jong, R. and Wang, H. 2014. Water use efficiency of spring wheat in the semi-arid Canadian prairies: Effect of legume green manure, type of spring wheat, and cropping frequency. Can. J. Soil Sci. 94: 223–235. In the semi-arid Canadian prairie, water is the main determinant of crop production; thus its efficient use is of major agronomic interest. Previous research in this region has demonstrated that the most meaningful way to measure water use efficiency (WUE) is to use either precipitation use efficiency (PUE) or a modified WUE that accounts for the inefficient use of water in cropping systems that include summer fallow. In this paper, we use these efficiency measures to determine how cropping frequency, inclusion of a legume green manure, and the type of spring wheat [high-yielding Canada Prairie Spring (CPS) vs. Canada Western Red Spring (CWRS)] influence WUE using 25 yr of data (1987–2011) from the “New Rotation” experiment conducted at Swift Current, Saskatchewan. This is a well-fertilized study that uses minimum and no-tillage techniques and snow management to enhance soil water capture. We compare these results to those from a 39-yr “Old Rotation” experiment, also at Swift Current, which uses conventional tillage management. Our results confirmed the positive effect on WUE of cropping intensity, and of CPS wheat compared with CWRS wheat, while demonstrating the negative effect on WUE of a green manure crop in wheat-based rotations in semiarid conditions. Furthermore, we identified a likely advantage of using reduced tillage coupled with water conserving snow management techniques for enhancing the efficiency of water use.

2012 ◽  
Vol 92 (4) ◽  
pp. 573-587 ◽  
Author(s):  
R. Kröbel ◽  
C. A. Campbell ◽  
R. P. Zentner ◽  
R. Lemke ◽  
H. Steppuhn ◽  
...  

Kröbel, R., Campbell, C. A., Zentner, R. P., Lemke, R., Steppuhn, H., Desjardins, R. L. and De Jong, R. 2012. Nitrogen and phosphorus effects on water use efficiency of spring wheat grown in a semi-arid region of the Canadian prairies. Can. J. Soil Sci. 92: 573–587. Water use efficiency (WUE) has often been analyzed for semiarid environments, but fallow-containing cropping systems were assessed inappropriately. Further, these short-term studies are unlikely to correctly assess weather variability impacts in such environments. We assessed the impact of fertilizer N and P on water use efficiency (WUE) and precipitation use efficiency (PUE) of spring wheat (Triticum aestivum L.) from a 39-yr long-term crop rotation study in semi-arid southwestern Saskatchewan. In the rotation experiment, continuous wheat (Cont W) with N+P or P fertilizer only, and fallow-wheat-wheat (F-W-W) with N+P, P only, or N only were studied. We calculated WUE using: (i) Yield (Y)/[water use (WU)/potential water use (PET)]; (ii) Y/WU; (iii) Y/WU with a fallow phase element added; and (iv) Y/harvest-to-harvest precipitation (PUE). The WUEs in the rotation experiment were generally greater for treatments with N+P fertilizer, and greatest after an increase of N application coupled with favourable soil water conditions in the final decades of this study. In cases (i) and (ii), WUE for F-W-W was greater than for the Cont W-treatment. In case (iii), the WUEs were 5.7, 4.5, 3.9, 3.6, and 3.6 kg ha−1 mm−1 water for Cont W (N+P), Cont W (P), F-W-W (N+P), F-W-W (P), and F-W-W (N), respectively. For PUE [case (iv)] the values were 4.0, 3.1, 3.4, 3.0, and 2.9, respectively. We concluded that case (ii) was most appropriate for continuous cropping and case (iii) for systems including fallow, while case (iv) was usable in general.


2022 ◽  
Vol 32 (1) ◽  
pp. 21-27
Author(s):  
Osama Mohawesh ◽  
Ammar Albalasmeh ◽  
Sanjit Deb ◽  
Sukhbir Singh ◽  
Catherine Simpson ◽  
...  

Colored shading nets have been increasingly studied in semi-arid crop production systems, primarily because of their ability to reduce solar radiation with the attendant reductions in air, plant, and soil temperatures. However, there is a paucity of research concerning the impact of colored shading nets on various crops grown under semi-arid environments, particularly the sweet pepper (Capsicum annum) production system. This study aimed to investigate the effects of three colored shading net treatments (i.e., white, green, and black shading nets with 50% shading intensity and control with unshaded conditions) on the growth and instantaneous water use efficiency (WUE) of sweet pepper. The results showed that all colored shading nets exhibited significantly lower daytime air temperatures and light intensity (22 to 28 °C and 9992 lx, respectively) compared with the control (32 to 37 °C and 24,973 lx, respectively). There were significant differences in sweet pepper growth performance among treatments, including plant height, shoot dry weight, leaf area, leaf chlorophyll content, and vitamin C in ripened fruit. The enhanced photosynthetic rates were observed in sweet pepper plants under the colored shading nets compared with control plants. WUE increased among the colored shading net treatments in the following order: control ≤ white < black < green. Overall, the application of green and black shading nets to sweet pepper production systems under semi-arid environments significantly enhanced plant growth responses and WUE.


1997 ◽  
Vol 77 (3) ◽  
pp. 359-366 ◽  
Author(s):  
H. W. Cutforth ◽  
B. G. McConkey

In the semiarid region of the western Canadian prairies, seeding directly into standing cereal stubble is gaining popularity. This four year study was conducted at Swift Current, SK, to determine how seeding into tall (>30 cm high), short (about 15 cm high) and cultivated cereal stubble altered the microclimate thereby affecting the growth and yield of hard red spring wheat (Triticum aestivum L.). The treatments were deployed immediately before seeding on plots that had overwintered with tall stubble. Seeding wheat into tall stubble increased grain yield and water use efficiency by about 12% compared to wheat seeded into cultivated stubble. Yield and water use efficiency for wheat seeded into short stubble were intermediate to the other stubble treatments. As well, wheat seeded into tall stubble grew taller than wheat seeded into the cultivated stubble. Further, there was a tendency for spring wheat grown in tall stubble to produce more dry matter and more leaf area, to have a lower proportion of dry matter as leaves and a higher proportion as stems, and to have a lower harvest index than the other treatments.Growing season evapotranspiration (ET) was not affected by stubble height. When the seedlings were small, compared to cultivated stubble, tall stubble altered the microclimate near the soil surface by reducing the daily average windspeed, soil temperature, and incoming solar radiation, and increasing the reflected solar radiation. Throughout much of the growing season, potential ET at the soil surface, measured with minilysimeters, was significantly lower in the tall stubble. Tall stubble, compared to cultivated stubble, increased the proportion of ET that was transpired by the wheat. As well, reduced windspeeds and increased photosynthetic area may have increased the efficiency of net carbon assimilation. To increase grain yields, producers in the semiarid prairies who direct-seed spring wheat are advised to seed into stubble left standing as tall as practical (at least 30 cm). Key words: Standing stubble, wheat, microclimate, water use, yield


2004 ◽  
Vol 84 (1) ◽  
pp. 11-22 ◽  
Author(s):  
R. P. Zentner ◽  
C. A. Campbell ◽  
V. O. Biederbeck ◽  
F. Selles ◽  
R. Lemke ◽  
...  

In the Brown soil zone of western Canada summerfallowing (F) is traditionally used to reduce the water deficit associated with cereal production, but frequent use of this practice results in soil degradation and reduces the N-supplying capacity of soils. Some scientists suggest that an annual legume green manure crop (LGM) could be used as a partial-fallow replacement to protect the soil against erosion and increase its N fertility, particularly when combined with a snow-trapping technique to replenish soil water used by the legume. We assessed this possibility by comparing yields, N economy, water use efficiency, and economic returns for hard red spring wheat (W) (Triticum aestivum L.) grown in rotation with Indianhead black lentil (Lens culinaris Medikus) green manure (i.e., LGM-W-W) vs. that obtained in a traditional F-W-W system. Further, we assessed whether a change in manage ment of the LGM crop (i.e., moving to earlier seeding and earlier turn-down) was advantageous to the overall performance of this practice. The study was conducted over 12 yr (1988–99) on a medium-textured Orthic Brown Chernozem at Swift Current, Saskatchewan. Wheat stubble was left tall to trap snow, tillage was kept to a minimum, and the wheat was fertilized based on NO3 soil tests. When we examined results after 6 yr, we concluded that by waiting until full bloom to turn down the legume (usually late July or early August) so as to maximize N2 fixation, soil water was being depleted to the detriment of yields of the following wheat crop. The change in management of the LGM crop since 1993 resulted in wheat yields following LGM equaling those after fallow (due to improved water use efficiency), a gradual and significant increase over time in grain protein and in N yield of aboveground plant biomass of wheat in the LGM-W-W compared to the F-W-W system, plus a gradual decrease in fertilizer N requirements of wheat in the LGM system accompanying an improvement in the N supplying power of the soil. These savings in N fertilizer, together with savings in tillage and herbicide costs for weed control on partial-fallow vs. conventional-fallow areas, and higher revenues from the enhanced grain protein, more than offset the added costs for seed and management of the LGM crop. Thus, our results imply that, if producers seed the LGM in April and turn it down in early July, an annual LGM-cereal rotation is a viable option in the semiarid Canadian prairies; however, one negative consequence of adopting this management strategy is the possibility of enhancing NO3 leaching. Key words: Nitrogen yields, grain protein, green fallow, summerfallow substitute, economic returns, NO3 leaching


2004 ◽  
Vol 84 (2) ◽  
pp. 487-501 ◽  
Author(s):  
C. A. Campbell ◽  
R. P. Zentner ◽  
F. Selles ◽  
V. O. Biederbeck ◽  
B. G. McConkey ◽  
...  

Producers in the semiarid Canadian prairies practice frequent summerfallow to conserve water and reduce the risk of crop failure, but this practice promotes soil degradation. In contrast, annual cropping enhances soil quality but results in greater economic risk. We need to know what is the most suitable cropping frequency for this region. In 1985, based on results of the first 18 yr of a long-term crop rotation experiment being conducted on a medium-textured, Orthic Brown Chernozem at Swift Current, Saskatchewan, we modified the experiment to allow comparison of four cropping frequencies over the period 1985–2002. These were fallow-spring wheat (Triticum aestivum L.) (F-W), F-W-W, F-W-W-W-W-W, and continuous wheat (Cont W). All systems received recommended rates of N and P fertilizer. Growing season precipitation during the 1985–2002 period was 10% above average so that grain yields were also above average for this region. We assessed yields of grain, straw and N in aboveground plant parts, N concentration in grain and straw, harvest index, nitrogen harvest index and water use efficiency, and the average annual production (on a rotation basis) of grain, straw and aboveground N yield, and related these characteristics to water deficit. Water deficit was the main factor responsible for annual variations in the characteristics assessed. Of these characteristics, cropping frequency influenced only the average annual productivity factors; it rarely influenced the characteristics when they were assessed on a rotation-phase basis. Assuming cropping frequency (x) for the 2-yr, 3-yr, 6-yr and Cont W rotations is 50%, 67%, 83%, and 100%, respectively, then average annual yields (y) in kg ha-1 yr-1 were related to frequency as follows: (1) for grain yield y = 768 + 10.7 x, r2 = 0.99; (2) for straw yield y = 1159 + 18.9 x, r2 = 0.99; and (3) for aboveground plant N yield y = 23.7 + 0.36 x, r2 = 0.99. The regression between annual grain production and cropping frequency at Swift Current for 1985 to 2002 had a much higher slope than the relationship for the same experiment in the much drier 1967 to 1984 period. Further, the equations for Swift Current in 1985–2002 were similar to the relationships obtained for systems in the subhumid Black Chernozems, indicating such relationships are greatly influenced by weather conditions. These relationships may be useful for conducting economic analyses and for modeling N balance. We conducted an apparent N balance analysis which indicated that all four rotations have lost N from the system in inverse proportion to the frequency of cropping. However, changes in total N in the 0- to 0.3-m depth of soil suggest that they have not lost N and that Cont W gained N over the course of the study. We are not able to explain this apparent anomaly and recommend further research on this question. Key words: Fallow frequency, grain yield, N concentration, N yield, water deficit, water use efficiency, N balance


Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 632
Author(s):  
Weinan Lu ◽  
Wenxin Liu ◽  
Mengyang Hou ◽  
Yuanjie Deng ◽  
Yue Deng ◽  
...  

Improving agricultural water use efficiency (AWUE) is an important way to solve the shortage of water resources in arid and semi-arid regions. This study used the Super-DEA (data envelopment analysis) to measure the AWUE of 52 cities in Northwest China from 2000 to 2018. Based on spatial and temporal perspectives, it applied Exploratory Spatial Data Analysis (ESDA) to explore the dynamic evolution and regional differences of AWUE. A spatial econometric model was then used to analyze the main factors that influence the AWUE in Northwest China. The results showed firstly that the overall AWUE in Northwest China from 2000 to 2018 presented a steady upward trend. However, only a few cities achieved effective agricultural water usage by 2018, and the differences among cities were obvious. Secondly, AWUE showed an obvious spatial autocorrelation in Northwest China and showed significant high–high and low–low agglomeration characteristics. Thirdly, economic growth, urbanization development, and effective irrigation have significant, positive effects on AWUE, while per capita water resource has a significant, negative influence. Finally, when improving the AWUE in arid and semi-arid regions, plans should be formulated according to local conditions. The results of this study can provide new ideas on the study of AWUE in arid and semi-arid regions and provide references for the formulation of regional agricultural water resource utilization policies as well.


2016 ◽  
Vol 178 ◽  
pp. 137-147 ◽  
Author(s):  
Yanhao Lian ◽  
Shahzad Ali ◽  
Xudong Zhang ◽  
Tianlu Wang ◽  
Qi Liu ◽  
...  

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