71st SWCS International Annual Conference July 24-27, 2016 Louisville, KY

1. Effect of skip‐row planting on cotton
yield, biomass and soil moisture in
South Carolina
J.O. Payero, A. Khalilian, R. Davis,
M. Marshall, and A. Nafchi

2. NRCS‐CIG grant
Drought Adaptation Options:
1. Conservation Tillage
2. Cover Crop
3. Deficit Irrigation
4. Variable rate irrigation
5. Sensor‐based irrigation
6. Drought tolerant varieties
7. Skip‐row planting

3. Objectives:
• Demonstrate skip‐row planting to farmers in SC
• Evaluate agronomic, economic and
environmental benefits

5. 2013 (Dryland)
• FARMER – (S, SS)
• EREC – (S,SS, AS, DS)
Skip
(Included)
Solid
Skip
Skip
(Included)
Skip
(Included)
Solid
(Excluded)
Solid
(Included)
Rep 1 Rep 1 Rep 1
Solid
(Included)
Solid
(Excluded)
Solid
(Included)
Solid
(Excluded)

6. 2014
Planting Configurations:
• S, SS, DS, AS
Water regimes:
• Dryland
• Deficit irrigation
• Full irrigation

7. 2015Solid
Alternate Skip
Single Skip
Water regimes:
• Dryland
• Deficit irrigation
• Full irrigation
Planting:
• S, SS, DS, AS

8. Measurements
• Soil moisture
• Biomass
• Yield
• Economics

9. Decagon Watermark

10. Lint yield 2013

11. Biomass 2014
Biomass (g m‐2)
Configuration Full Deficit Dryland Average ΔB (%)
Solid (S) 1091 1072 856 1006 a 0%
Single Skip (SS) 1020 945 933 966 ab ‐4%
Double Skip (DS) 809 722 621 717 c ‐29%
Alternate Skip (AS) 938 682 689 770 bc ‐23%
ANOVA (P>F):
Planting configuration
Irrigation
***
*
Biomass (g m‐1)
Configuration Full Deficit Dryland Average ΔB (%)
Solid (S) 1091 1072 856 1006 a 0%
Single Skip (SS) 1359 1260 1244 1288 ab 28%
Double Skip (DS) 1618 1444 1242 1435 a 43%
Alternate Skip (AS) 1877 1363 1378 1540 a 53%
ANOVA (P>F):
Planting configuration
Irrigation
***
*

13. Dryland Biomass (g/m)

14. Dryland Biomass (g/m2)

15. 2013 ‐
Decagon

16. Cumulative soil water Gain & Use

17. 2014 ‐Watermark ‐

20. Cumulative Stress

21. Economics at EREC 2013
Item Solid Single
Skip
Alternate
Skip
Double
Skip
Seed cost ($/ac) $84.00 $56.28 $42.00 $42.00
Yield (lb/ac) 964 1129 765 831
2013 cotton price ($/lb) $0.90 $0.90 $0.90 $0.90
Gross Income ($/ac) $868 $1,016 $688 $748
Income - seed cost ($/ac) $784 $960 $646 $706
% income of Solid 100% 122% 83% 90%
Income over Solid ($/ac) - $176 (-$137) (-$78)

22. Economics at FARMER 2013
Item Solid Single Skip
Seed cost ($/ac) $84 $56.28
Yield (lb/ac) 939 1088
2013 cotton price ($/lb) $0.90 $0.90
Gross Income ($/ac) $845 $979
Income - seed cost ($/ac) $761 $923
% income of Solid 100% 121%
Income over Solid ($/ac) - $162

23. $0
$200
$400
$600
$800
$1,000
$1,200
Solid Single Skip Alternate skip Double Skip
E5 field Bates field
+$176/acre
‐$137/acre
‐$78/acre
Income ‐ Cost of seeds ($/acre)

24. Conclusions:
• The skip‐planting treatments tended to:
– Conserve soil water
– Produce bigger plants (higher biomass/m)
– Reduce biomass per unit area (g/m2).
• Biomass (and yield) of SS were similar to S.
• SS reduced seed cost and increased income,
but DS, and AS reduced income.