2017 SWCS Annual Conference July 30-August 2, 2017 Monona Terrace Convention Center

1. Improving Soil Health and Water
Dynamics in Deficit-Irrigated
Agriculture
Paul DeLaune1
Partson Mubvumba2
Katie Lewis3
Jamie Foster4
1 Texas A&M AgriLife Research at Vernon
2 Texas A&M University
3 Texas A&M AgriLife Research at Lubbock
4 Texas A&M AgriLife Research at Beeville

2. Lamesa
Chillicothe
Beeville
Demonstrating Soil Health
Promoting Practices to
Increase Water Holding
Capacity and Yield in Deficit-
Irrigated Agriculture
NRCS CIG Agreement#
69-3A75-14-246

4.  When to apply water? Irrigating in excess early in the season
to build soil water in the profile reduces irrigation water value
compared to applying irrigation water at critical growth stages
later in the year (Bordovsky et al.).
 How does conservation tillage impact water capture and
storage? Research in Texas Rolling Plains has shown higher
stored soil moisture entering the cropping system in
conservation tillage systems compared to conventional. Only
16% of Texas cropped acres in conservation tillage (ERS,
2013)
 Are cover crops detrimental to stored soil moisture? Initial
regional research shows cover crops have no major cash crop
yield impacts.
Questions/Objective

5.  Amarillo fine sandy loam
 Treatments implemented in
1998!
 Treatments
◉ Conventional Tillage
◉ No-till with wheat cover crop
◉ No-till with mixed species
cover crop
 See details in poster display.
Lamesa

6. Chillicothe Research Station
Clay Loam, NT since 2008; Strip-Till since 2011
Conventional Till No-Till No-Till with Cover Crop

7. Wheat and Mixed CC = 30 lb/ac;
Mixed Species: Rye (15), Austrian Winter field pea (10), hairy vetch (3), & radish (2)

9. Continuous Cotton Systems
CT ST NT NTC
Depth
(cm) Organic C (ppm)
0-10 8476 7242 6972 8346
10-20 6472 6155 5743 5872
20-30 6103 6002 5838 5684
30-60 5688 6375 5297 5275
60-90 6516 6848 4534 4404

10. 0
5
10
15
20
25
30
Con. Till
Conv. Till Strip-Till No-Till Mix Wheat
1-Day CO2-C
CO2(ppm)

11. 0
20
40
60
80
100
120
140
Con. Till Strip-Till No-Till Mix Wheat
Cont. Cotton Cotton/Sorghum
Water Extractable Organic C
WEOC(mg/kg)

12. Physical Properties
Depth(cm)

13. Resistance (kPa/cm)
0 1000 2000 3000 4000 5000
Depth(cm)
0
5
10
15
20
25
30
ConventionalTill
No-Till
0
0.1
0.2
0.3
0.4
0.5
0.6
Time 1 Time 2
Conv
No-Till
Infiltration(in/min)

14. Soil Moisture - Lamesa

15. Stored Soil Moisture

16. Stored Soil Moisture

17. 1200
1250
1300
1350
1400
1450
1500
1550
1600
1650
1700
Conv. Till Strip-Till No-Till NT Wheat Cover NT Mixed Cover
2016 Lint Yield
LintYield(lb/ac)

18. 200
210
220
230
240
250
260
270
280
Conv. Till Strip-Till No-Till NT Wheat Cover NT Mixed Cover
IWUE(lblint/inchappliedirrigation)
Irrigation Water Use Efficiency

19. 500
700
900
1100
1300
1500
1700
1900
Low Medium High
Conv. Till Strip-Till No-Till No-Till Wheat Cover
LintYield(lb/ac)
2016 Lint Yield
6” 7.5” 10.4”

20. 0
50
100
150
200
250
300
Low Medium High
Conv. Till Strip-Till No-Till No-Till Wheat Cover
IWUE(lb/ac)
2016 IWUE
6” 7.5” 10.4”

21.  Using C measurements (WEOC, SOC, CO2) have shown
little change or inconsistency.
 However, significant changes in soil physical properties have
been found due to conservation tillage.
 Stored soil moisture similar among tillage treatments, except
at peak cover crop growth. However, system is typically
recharged.
 Irrigation water use efficiencies have been noted for
conservation tillage with cover crops, particularly at deficit-
irrigated levels.
Conclusions

22. 22
Questions?
Paul DeLaune pbdelaune@ag.tamu.edu
Appreciation to USDA-NRCS CIG Program