WATER REQUIREMENTS OF IRRIGATED SOYBEANS IN SOUTHERN ALBERTA

1983 ◽  
Vol 63 (4) ◽  
pp. 855-860 ◽  
Author(s):  
E. H. HOBBS ◽  
H.-H. MUENDEL

Field experiments were conducted from 1979 to 1982 in southern Alberta to determine the seasonal water use of soybeans. Soil moisture was determined every 5–6 days throughout the growing season and irrigation water was applied when soil moisture tension in the top 30 cm reached −40 kPa, with an additional treatment of −60 kPa for 1980 and 1981. Seasonal water use in a year of normal growth (1980) varied from 426 to 482 mm for the drier and wetter treatments, respectively. The drier treatments in 1980 and 1981 resulted in more efficient use of water. Low early-season water use with peak use after full pod development (R4) was defined. Water use peaked in late July to early August with a requirement of 7 mm/day. Small changes in seed quality, tending towards higher protein and lower oil under wetter conditions, are corroborated in the literature. The possibility of integrating crop and cultivar selection with appropriate irrigation management to improve production efficiency in southern Alberta is discussed. The late-peak water requirement of soybeans combines well with the early-peak use of cereal crops to ensure efficient seasonal irrigation management.Key words: Glycine max (L.) Merr., évapotranspiration, seed protein, seed oil

2021 ◽  
Author(s):  
Marco Mancini ◽  
Chiara Corbari ◽  
Imen Ben Charfi ◽  
Ahmad Al Bitar ◽  
Drazen Skokovic ◽  
...  

<p>The conflicting use of water is becoming more and more evident, also in regions that are traditionally rich in water. With the world’s population projected to increase to 8.5 billion by 2030, the simultaneous growth in income will imply a substantial increase in demand for both water and food. Climate change impacts will further stress the water availability enhancing also its conflictual use. The agricultural sector is the biggest and least efficient water user, accounts for around 24% of total water use in Europe, peaking at 80% in the southern regions.</p><p>This paper shows the implementation of a system for real-time operative irrigation water management at high spatial and temporal able to monitor the crop water needs reducing the irrigation losses and increasing the water use efficiency, according to different agronomic practices supporting different level of water users from irrigation consortia to single farmers. The system couples together satellite (land surface temperature LST and vegetation information) and ground data, with pixel wise hydrological crop soil water energy balance model. In particular, the SAFY (Simple Algorithm for Yield) crop model has been coupled with the pixel wise energy water balance FEST-EWB model, which assimilate satellite LST for its soil parameters calibration. The essence of this coupled modelling is that the SAFY provides the leaf area index (LAI) evolution in time used by the FEST-EWB for evapotranspiration computation while FEST-EWB model provides soil moisture (SM) to SAFY model for computing crop grow for assigned water content.</p><p>The FEST-EWB-SAFY has been firstly calibrated in specific fields of Chiese (maize crop) and Capitanata (tomatoes) where ground measurements of evapotranspiration, soil moisture and crop yields are available, as well as LAI from Sentinel2-Landsat 7 and 8 data. The FEST-EWB-SAFY model has then been validated also on several fields of the RICA farms database in the two Italian consortia, where the economic data are available plus the crop yield. Finally, the modelled maps of LAI have then been validated over the whole Consortium area (Chiese and Capitanata) against satellite data of LAI from Landsat 7 and 8, and Sentinel-2.</p><p>Optimized irrigation volumes are assessed based on a soil moisture thresholds criterion, allowing to reduce the passages over the field capacity threshold reducing the percolation flux with a saving of irrigation volume without affecting evapotranspiration and so that the crop production. The implemented strategy has shown a significative irrigation water saving, also in this area where a traditional careful use of water is assessed.</p><p>The activity is part of the European project RET-SIF (www.retsif.polimi.it).</p>


1984 ◽  
Vol 20 (2) ◽  
pp. 151-159
Author(s):  
D. Boobathi Babu ◽  
S. P. Singh

SUMMARYThe results of field experiments conducted in the spring seasons (February/March to June) of 1980 and 1981 indicate that grain yields of sorghum increased with increase in frequency of irrigation. Crops sprayed with atrazine or CCC yielded more than the unsprayed control; maximum yields were obtained by the application of atrazine at 200 g ha−1. Water use efficiency decreased with increase in irrigation but increased as a result of spraying crops with either chemical. Irrigation water can be saved by the spraying of atrazine or CCC onto spring-sown sorghum.


1977 ◽  
Vol 57 (3) ◽  
pp. 891-896 ◽  
Author(s):  
K. K. KROGMAN ◽  
E. H. HOBBS

In field plot experiments conducted in southern Alberta over a 6-yr period, highest seed yields of alfalfa (Medicago sativa L. cv. Beaver) were obtained with one or two irrigations in the first half of the growing season. In outdoor lysimeters protected from rain, moisture stress for more than 8 days before seed ripening severely reduced seed production. Under field conditions, stored soil moisture from irrigation during the vegetative stage of growth plus occasional rain in July and August permitted irrigation of alfalfa for seed to be stopped at the bud to early bloom stage (June to early July).


New Medit ◽  
2021 ◽  
Vol 20 (2) ◽  
Author(s):  

This paper examines irrigation management within the Tunisian Water Users Association (WUA),in Nadhour public irrigated area (central of Tunisia). The functioning of 14 WUAs was evaluated based on questionnaires and related interviews. The methodology of this study consists of two main steps; (i) an estimation of technical efficiency scores of 90 smallholder farmers and the sub-vector of WUE (Water Use efficiency) using the non-parametric DEA model, (ii) a regression of a Tobit model to test the hypothesis regarding explanatory variables of differentiated technical efficiency scores. The investigation shows an average technical efficiency of 70.8% and WUE of 64.8%. It highlighted the Water turn, the infrastructure state, the water supply shortage, corruption, and free-riding behaviors as tightly correlated factors with farm’s productivity. This suggests that there is potential to improve production efficiency by implementing targeted programs and rules for inefficient farmers. The findings of this study show that it is important to fight corruption in the water sector by an increased government oversight, reform of regulations, and increased accountability


1984 ◽  
Vol 20 (2) ◽  
pp. 151-159 ◽  
Author(s):  
D. Boobathi Babu ◽  
S. P. Singh

SUMMARYThe results of field experiments conducted in the spring seasons (February/March to June) of 1980 and 1981 indicate that grain yields of sorghum increased with increase in frequency of irrigation. Crops sprayed with atrazine or CCC yielded more than the unsprayed control; maximum yields were obtained by the application of atrazine at 200 g ha−1. Water use efficiency decreased with increase in irrigation but increased as a result of spraying crops with either chemical. Irrigation water can be saved by the spraying of atrazine or CCC onto spring-sown sorghum.


1967 ◽  
Vol 47 (2) ◽  
pp. 131-138 ◽  
Author(s):  
K. Pohjakas ◽  
D. W. L. Read ◽  
H. C. Korven

Irrigation water was applied by the surface method to nine perennial and five annual crops grown at Swift Current. Soil moisture content was maintained between 50% of available moisture and the field capacity. Soil moisture stresses were measured by tensiometers. The total water use and peak requirements varied depending on the season. The total mean water use for perennial forages varied from 589 to 688 mm, and averaged 526 mm for wheat, 486 mm for barley, 610 mm for sugar beets and 560 mm for potatoes.Consumptive use: evaporation ratios were calculated from the Experimental Farms buried tank, a Class A pan, and black Bellani plate atmometers. The water use to evaporation ratio (U: E) from the Experimental Farms buried tank ranged from 0.81 to 1.14, for the Class A pan it was from 0.53 to 0.75, and for the black Bellani plates from 0.321 to 0.446. In all cases the perennial crops were at the higher end and the annual crops were at the lower end of the range.Three to eight irrigations were applied per season. Seasonal water use by annual crops was slightly higher at Swift Current than the rates reported for Lethbridge and Vauxhall, Alberta.


1987 ◽  
Vol 67 (4) ◽  
pp. 877-891 ◽  
Author(s):  
D. C. MaCKAY ◽  
J. M. CAREFOOT

A series of 10 field experiments conducted over a 4-yr period (1973–1976) on three of the most important Brown Chernozemic soils in the irrigated area of southern Alberta gave no significant yield responses to applied K (at rates of 0, 50, 100 and 150 kg ha −1 in 1973 and 0, 127, 254 and 508 kg ha−1 in the other years), using potato (Solanum tuberosum L.) as the test crop. The experiments included several cultivars, a variety of growing conditions, and diverse cropping histories. In addition, the K concentration of uppermost mature leaf blades obtained at the 10%-bloom stage were only slightly affected by K treatments, except in 1 yr (1975). The increased K uptake in 1975 was related to greater precipitation before irrigation was applied (66, 99 and 94 mm, respectively) during April, May and June in comparison with the long-term average of 32, 54 and 76 mm. The effects of early-season soil moisture stress were partially confirmed in a controlled environment (CE) experiment in which maintenance of soil water potentials between −30 and −20 kPa throughout the season caused greater uptake of added K in comparison with soil moisture stress in the 0–15 cm zone prior to the 10%-bloom stage. Yields of tubers were depressed with the stressed treatment, but there was no yield response to added K. Leaf analyses from the field experiments indicate that the critical K level of 43 g kg−1, which was established earlier for the Russet Burbank cultivar growing on Podzol soils is too high for irrigated Chernozemic soils, and that 30 g kg−1 would be a more valid tentative value. In a second CE experiment, designed to quantify the fate of applied K during intensive cropping, no yield responses to K applications were obtained with alfalfa on a coarse-textured Cavendish sandy loam during a 2-yr period. With no applied K, crop uptake reduced exchangeable K levels throughout the entire profile (66 cm) by about 20%. Thirty percent of the K removed by the crop originated from nonexchangeable soil K. With the highest K rate (450 kg ha−1 applied twice), 50% could be attributed to plant uptake, 15% to increased exchangeable K, and 35% to fixation in the nonexchangeable form. It is concluded that response to applied K on irrigated Brown and Dark Brown Chernozemic soils of southern Alberta is unlikely, even with intensive cropping, for some time in the future. A practical strategy for producers could be to apply moderate rates of K as a conservation measure when economic conditions are favorable and to rely on soil reserves in times of financial pressures. Key words: K-release, K-fixation, leaf analysis, fertilizer K requirements, soil water stress, K deficiency


2019 ◽  
Vol 113 (2) ◽  
pp. 307
Author(s):  
Mina ABDOLAHI ◽  
Saeideh MALEKI FARAHANI

<p>This study investigated the effect of drought stress on the yield, water use efficiency (WUE), physiology, and seed quality of two species Lallemantia sp. Field experiments with three irrigation regimes were carried out in a split plot factorial in a randomized complete block design with three replications. Treatments included irrigation after 40 %, 60 %, and 100 % depletion of available soil water (ASW) (I40, I60, and I100, respectively) as main plots and Lallemantia species L. iberica (M. Bieb.) Fisch. &amp; C. A. Mey. (S1) and L. royleana Benth. in Wall (S2) as subplots. Increment in depletion of ASW (I40 to I100) resulted in progressively less chlorophyll a content (Chl­ a), open stomata percentage (OS), and leaf area index (LAI). The highest Chl­ a and LAI were found to be 0.0087­ mg g−1, and 2.68 mg g−1 leaf mass in I40 treatment, respectively, while closed stomata percentage (CS) increased significantly as drought stress increased. The results of this experiment indicated that the appropriate yield of production was obtained in plots which were fully irrigated (I40) for all species of Lallemantia; however, the WUE increased as drought stress increased. The interaction of drought stress, Lallemantia species with grain yield and WUE was significant.</p>


2012 ◽  
Vol 622-623 ◽  
pp. 1725-1729
Author(s):  
Jian Guo Shi ◽  
Jing Hui Liu ◽  
Li Xin Jia ◽  
Bao Ping Zhao ◽  
Li Jun Li ◽  
...  

Aiming at reducing agricultural pollution caused by plastic film and increasing soil moisture and water use efficiency (WUE), the field experiments were conducted to investigate the effects of re-used plastic film mulching on soil moisture, sunflower’s yield and water use efficiency by compared with new plastic film mulching and bare field in Hetao area, China. The results showed that, soil water of re-used film mulching increased at different degree. Compared with bare field and new film mulching, soi1 moisture of re-used film were higher significantly 1.5 percentage points in 0-100 cm, and especially 1.9 or 2.6 percentage points in 0-10 cm during sunflower’s growth stage. Soil water of re-used film was more than that of bare field 24.8 mm (in 2010) and 33.0 mm (in 2011) before seeding, and 21.6mm (in 2010) and 24.5mm (in 2011) at harvest when soil water was replenished to same level for each treatment before sowing. Meanwhile, the grain yield of re-used film was higher significantly than that of bare field 11.4% (in 2010) and 16.8% (in 2011), and WUE of re-used film was higher significantly 15.7% (in 2010) and 22.7% (in 2011) respectively, no significant with new film. So it was worth to apply re-used film to agriculture production for improving the soil moisture, enhancing water use efficiency and increasing the yield of sunflower. We suggest that the application of re-used film mulching is a suitable soil management practice for increase water and WUE in Hetao area or other areas with similar conditions.


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