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Monthly average air temperatures (°C), precipitation (including 30-yr average) (mm) and reference evapotranspiration (ETo) (mm) for Las Cruces, NM during the research period (January 2005–December 2007).

 
Year Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec.
Air temperature, °C
2005 8.3 9.3 9.2 17.3 22.2 27.1 28.8 25.7 24.5 16.8 11.2 6.4
2006 8 10.6 13.6 19.3 23.6 27.7 27.7 24.7 20.9 16.1 11.3 5.6
2007 5.3 9.1 14 17.1 21.6 26.3 26.8 27.3 24.2 17.9 11.6 6.4
Precipitation, mm
2005 23 62 4 6 11 0 7 29 64 28 0 0
2006 1 4 0 1 9 6 33 127 112 61 4 3
2007 35 2 2 16 36 49 5 49 28 29 2 7
30 yr mean 10 10 8 6 8 15 39 48 32 20 11 14
ETo, mm
2005 66 64 147 216 237 190 234 181 161 100 83 0
2006 75 54 84 178 223 231 210 162 146 103 78 0
2007 65 98 143 179 211 233 203 172 106 126 12 12



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Chemical analysis of potable, moderately saline, and saline water used in the study.

 
Water quality
Constituents Potable Moderately saline Saline
pH 7.98 7.69 7.52
Electrical conductivity, dS m−1 0.6 2.0 3.5
Total dissolved solids, mg L−1 400 1300 2200
Magnesium, meq L−1 0.8 1.68 2.52
Calcium, meq L−1 2.8 3.19 5.05
Sodium, mg L−1 48 230 400
Sodium adsorption ratio (SAR) 1.55 6.41 8.94
Potassium, mg L−1 4.6 28.0 51.2
Carbonate, meq L−1 0.00 0.00 0.00
Bicarbonate, meq L−1 2.84 6.43 9.95
Residual sodium carbonate, meq L−1 not detected 1.56 2.38



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Initial (pre-experiment) soil chemical characteristics at the research site.

 
Depth, cm
Soil characteristics 0–10 10–20 50–60
pH 8.7 8.5 8.4
EC†, dS m−1 0.22 0.21 0.23
Mg, meq L−1 0.4 0.4 0.4
Ca, meq L−1 2.4 2.2 1.7
Na, ppm 16 14 28
Cl, meq L−1 0.2 0.14 0.1
K, meq L−1 0.3 0.1 0.1
Sodium adsorption ratio 0.59 0.53 1.17
Organic matter, % 0.4 0.4 0.4
Electrical conductivity of a saturated paste extract.



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Results of analysis of variance testing the effects of water quality, irrigation systems, sampling times, and their interactions on root zone salinity (electrical conductivity [EC], Na, and sodium adsorption ration [SAR]) at soil depths of 0 to 20 cm (in 10-cm increments hence depth as additional treatment) and 50 to 60 cm.

 
Soil depth
0–20 cm
50–60 cm
Effect EC Na SAR EC Na SAR
Irrigation (I) * ns‡ ns ns ns **
Water quality (W) *** *** *** *** ** ***
I × W ns ns ns ns ns ns
Sampling date (S) *** *** *** *** *** ***
I × S * ns * ns ns *
W × S *** *** *** ns ns ***
I × W × S ns ns ns ns ns ns
Depth (D) *** *** ns
I × D *** *** **
W × D ns ns ns
I × W × D ns ns ns
D × S ns * *
I × D × S ns * ns
W × D × S ns ns ns
I × W × D × S ns ns ns
* Significant F test at the 0.05 level of probability.
** Significant F test at the 0.01 level of probability.
*** Significant F test at the 0.001 level of probability.
ns, not significant at the 0.05 probability level.



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. Soil electrical conductivity (dS m−1) and Na content (mg L−1) for the 50- to 60-cm soil depth irrigated with moderately saline, saline, and potable water. Data are pooled over irrigation systems (drip and sprinkler) and values represent an average of six readings (two irrigation systems and three replications).

 
Water quality EC Na
dS m−1 mg L−1
Moderately saline 1.7b† 275.3b
Potable 0.9b 86.5b
Saline 2.8a 503.9a
Values followed by the same letter are not significantly different from one another (Fisher's protected LSD, α = 0.05). Letters denote differences between three water qualities separately for electrical conductivity (EC) and Na content (in columns).



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Results of analysis of variance testing the effects of water quality, irrigation systems, sampling dates, and their interactions on quality, cover, and normalized difference vegetation indices (NDVI) of seven turfgrasses.

 
Effect Quality Cover Quality 2007 NDVI
Cultivar (C) *** *** *** **
Irrigation (I) ns† ns ns **
C × I ns ns ns ns
Water quality (W) *** ns ** **
C × W *** ns * ns
I × W ns ns ns ns
C × I × W ns ns ns ns
Sampling date (S)‡ *** *** *** ***
C × S *** *** * ns
I × S *** * *** ***
C × I × S ns ns ns ns
W × S *** *** ns ***
C × W × S ns ns ns ns
I × W × S *** * *** **
C × I × W × S ns ns ns ns
* Significant F test at the 0.05 level of probability.
** Significant F test at the 0.01 level of probability.
*** Significant F test at the 0.001 level of probability.
ns, not significant at the 0.05 probability level.
Sampling date for ‘Quality’ and ‘Cover’ indicates monthly visual ratings that were averaged for seasons spring, summer, and fall throughout the research period (2005–2007). Sampling date for Quality 2007 and NDVI indicates monthly ratings and measurements from March 2007 to October 2007 only.



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Quality (from 1 = worst to 9 = best) of seven cool-season turfgrasses during spring, summer, and fall of 2005, 2006, and 2007. Data are pooled over three water qualities (potable, moderately saline, and saline) and two irrigation systems (sprinkler and drip) and represent an average of 18 readings (three water qualities, two irrigation systems, and three replications).

 
2005
2006
2007
Cultivar Spring Summer Fall Spring Summer Fall Spring Summer Fall Mean
Brightstar SLT 5.4ab† 5.3c 5.2cd 5.6bc 5.5b 5.3cd 4.5bc 4.1bc 4.5b 5.1cd
Catalina 5.0c 5.1cd 5.2cd 5.0cd 5.4b 4.8de 4.2c 4.1bc 4.4bc 4.8de
Dawson 5.6a 6.1ab 6.1b 5.8ab 5.8b 5.5bc 4.7b 4.2b 4.0bc 5.3c
Fults 5.0bc 4.7d 4.3e 4.1e 4.0d 3.9f 3.8c 3.4d 3.8c 4.1f
Salty 5.5a 5.1cd 4.7de 4.9d 4.9c 4.4ef 4.2c 3.7cd 4.2bc 4.6e
Southeast 5.5a 5.9b 5.5bc 5.4bc 5.8b 5.9b 5.6a 5.7a 5.6a 5.7b
Tar Heel II 5.6a 6.6a 7.3a 6.3a 6.8a 7.2a 5.8a 5.9a 6.0a 6.4a
Mean 5.4ABC‡ 5.5A 5.5AB 5.3BC 5.5ABC 5.3C 4.7D 4.5E 4.7D
Values followed by the same letter are not significantly different from one another (Fisher's protected LSD, α = 0.05). Lowercase letters denote differences between cultivars separately for each season (in columns).
Values followed by the same letter are not significantly different from one another (Fisher's protected LSD, α = 0.05). Uppercase letters denote differences of the mean values between seasons during 3 yr (in row).



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Quality (from 1 = worst to 9 = best) of seven turfgrasses irrigated with potable, moderately saline, and saline water. Data are pooled over two irrigation systems (sprinkler and drip), 3 yr (2005, 2006, and 2007), three seasons (spring, summer, and fall), and values represent an average of 54 readings (two irrigation systems, 3 yr, three seasons, and three replications).

 
Cultivar Potable Moderately saline Saline
Brightstar LST 5.8b†A‡ 5.4cA 3.9cB
Catalina 5.7bA 4.9cB 3.8cC
Dawson 5.9bA 5.1cB 5.0bB
Fults 4.3d 4.2d 3.9c
Salty 4.9c 4.5d 4.5b
Southeast 5.7bA 6.1bA 5.2aB
Tar Heel II 6.7aA 6.8aA 5.7aB
Mean 5.6A 5.3A 4.6B
Values followed by the same letter are not significantly different from one another (Fisher's protected LSD, α = 0.05). Lowercase letters denote differences between cultivars separately for each water quality (in columns),
Values followed by the same letter are not significantly different from one another (Fisher's protected LSD, α = 0.05). Uppercase letters denote differences between three water qualities (in rows).