1. Yield of Chile Peppers Irrigated with Brackish Groundwater and Reverse Osmosis Concentrate
Manoj K Shukla, Ph.D.
Nakayama Chair and Professor of Soil Physics
Department of Plant and Environmental Sciences
New Mexico State University, Las Cruces, USA

2. Collaborators Gurjinder Singh Baath, Graduate student
Alison Flores, Graduate student
Omar Ozturk, Graduate student
Manoj Shukla, Professor
Paul Bosland, Professor
Stephanie Walker, Associate Professor
Randy Shaw, BGNDRF, Alamogordo

3. World Population Model Projections: 2 of 3 show growth Food Security ?
UN Projections in 2010
Model Projections:
2 of 3 show growth
Food Security ?
Water for Irrigation ?
Pest Problems, etc.?

4. Water Scarcity Across the World
IWMI – International Water Management Institute – Annual Report 2007

5. Las Cruces, NM

6. Elephant Butt Reservoir T OR C, New Mexico
~2% capacity from 2.6 M acre-ft
August 2016

7. Water Allotment to NM Farms by EBID
* 36 acre-inches per acre is considered as full allotment. Less than adequate for most years

8. Surface Water Availability for Irrigation in NM is declining
And will the situation improve????
How is our groundwater?

9. Depth to groundwater with total dissolved-solids concentration (TDS) greater than 1,000 milligrams per liter in the United States (modified from Feth and others, 1965)

10. Water Type
TDS (mg/L)
Fresh
<500
Brackish
,000
Saline
10,000-35,000
Brine
35, ,000
Salt Saturated
>250,000
Aquifer water salinity is variable
Usually deeper aquifers are more saline

11. Total volume of water in aquifers in New Mexico = 20 billion acre-feet
Not available everywhere
75% is too saline
25% < 2000 mg/L
NMWRRI Trans-boundary Aquifer Assessment (Hawley and Kennedy, 2004)

12. Use of Brackish Groundwater: Treated and Untreated
Using Untreated for Irrigation will Increase soil salinity
Treating brackish water: GOOD for soil
How to Treat brackish water?

13. What to do with the Concentrate? And other constituents?
KBHD facility, El Paso, TX
BGNDRF, Alamogordo, NM
New plant will have 1 MGD, expandable to 6 MGD
27.5 million gallons of fresh water daily (MGD)
Deep well injection
Evaporation pond
Agriculture
What to do with the Concentrate?
And other constituents?
Is Desalination a viable option for cleaning saline water in NM?

14. Brackish groundwater and Reverse Osmosis (RO) concentrate was provided by Brackish Groundwater National Desalination Facility, Alamogordo, NM
Water EC
SAR Mg Ca Na K Cl
SO4
mg/L
Brackish Water
2000
2.77
113
268
216
220
419
848
Brackish water
3300
3.55
191
424
352
233
683
1561
RO Concentrate
5300
5.13
275
600
607
398
1210
2148

15. Objectives
How will irrigation with brackish groundwater and reverse osmosis (RO) concentrate change chile pepper:
seed germination?
height at different stages?
yields?
Chile pepper varieties selected were:
AZ 1904, NuMex Joe E. Parker, NuMex Sandia Select, LB25, 3441

16. 5 Irrigation Salinity treatments:
Tap water of EC 400 ppm (control),
Brackish groundwater of EC 1300, 1700, 2000, 2600 ppm
4 seeds placed within 1-2 cm soil depth
Irrigation treatments applied at 3-4 days interval
Germination recorded every 2 days
Healthy plants transferred into bigger plots for survival, growth, and yield
Brackish groundwater of EC 2000, 3300 ppm
RO concentrate of EC 5300 ppm

17. Mean Seed Germination
400
1300
1700
2000
2600
Mean Germination percentage did not change with irrigation water salinity
Baath et al., 2015

18. Mean Germination Time (days)
 Treatments
(ppm)
Mean Germination Time (days)
400 (control)
 11.19 d
11.02 d
2000
12.15 c
11.95 c
3300
14.10 b
13.99 b
5300
14.95 a
14.88 a
LSD (0.05)
0.69
0.52
But time to germination increased with increasing irrigation water salinity

19. On day 40, differences were observed
Initially there were no differences in mean height of 6 chile pepper cultivars with increasing irrigation water salinity
On day 40, differences were observed
Subsequently differences started to become more pronounced
400 ppm
2000
ppm
3300
ppm
5300 ppm

20. Days to Flowering decreased with increasing irrigation water salinity
Treatments
Experiment 1
Days to flowering
Experiment 2
400 (control)
  a a
2000 a a
3300 b b
5300 b b
LSD (0.05)
2.72
2.93

21. All chile peppers irrigated with the same type of water had similar biomass yields
Yields became significantly lower with increasing irrigation water salinity

22. Early fruiting observed in brackish and RO water treatments
400 mg/L
2000
3300
5300
Yield decline observed for chile peppers irrigated with water > 2000 mg/L
Early fruiting observed in brackish and RO water treatments

23. Photosynthetic rate, Stomatal conductance and transpiration rate decreased with increasing irrigation water salinity

24. What to do with RO concentrate? Irrigate Halophytes?
Chile peepers show yield decline when irrigated with brackish groundwater and RO concentrate
What to do with RO concentrate?
Irrigate Halophytes?
Potential forage crops?
Season 1
Season 2
Species
Treatment (mg/L)
Fresh Wt (g) ± SE
H. Vulgare L.
530
20.67 ± 1.01
30.78 ± 1.46 a
Barley
3300
20.53 ± 2.49
29.26 ± 1.37 a
5300
17.78 ± 1.88
24.05 ± 0.98 b
6700
20.03 ± 2.66
31.32 ± 0.80 a
xTriticosecale
13.99 ± 0.53 c
14.03 ± 0.87
Triticale
15.04 ± 0.49 bc
13.08 ± 1.28
Wheat x Rye
16.71 ± 1.17 ba
10.93 ± 0.99
18.70 ± 0.99 a
12.64 ± 1.04
Flores et al., 2016; Ozturk et al., 2017

25. Summary
For Chile Peppers, irrigation with increasing water salinity resulted in:
Delayed Germination
Early flowering
Decrease in plant height after 40 days
Decrease in total biomass
Decrease in evapotranspiration
Low photosynthetic rate, transpiration rate, and stomatal conductance
Brackish groundwater should be treated prior to irrigation and the RO concentrate could be used to grow salt tolerant food or forage crops (halophytes) away from chile fields

26. Acknowledgement
Grad and Undergrad students and postdoc (Flores, Sharma, Ozturk, Baath, Fernandez, Gonzalez)
“John" Kaichiro and Tome Nakayama Professorship and Chair endowment
Brackish Groundwater National Desalination Facility, Alamogordo
NMSU Agricultural Experiment Station
WRRI NMSU

27. Thanks