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
NRCS‐CIG grant Drought Adaptation Options:
1. Conservation Tillage2. Cover Crop3. Deficit Irrigation4. Variable rate irrigation5. Sensor‐based irrigation6. Drought tolerant varieties7. Skip‐row planting
Objectives:
• Demonstrate skip‐row planting to farmers in SC
• Evaluate agronomic, economic and environmental benefits
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)
2014 Planting Configurations:• S, SS, DS, AS
Water regimes:• Dryland• Deficit irrigation • Full irrigation
2015Solid
Alternate SkipSingle Skip
Water regimes:• Dryland• Deficit irrigation • Full irrigation
Planting:• S, SS, DS, AS
Measurements
• Soil moisture• Biomass• Yield• Economics
Decagon Watermark
Lint yield 2013
Biomass 2014Biomass (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 configurationIrrigation
****
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 configurationIrrigation
****
Dryland Biomass (g/m)
Dryland Biomass (g/m2)
2013 ‐Decagon
Cumulative soil water Gain & Use
2014 ‐Watermark ‐
Cumulative Stress
Economics at EREC 2013
Item Solid SingleSkip
AlternateSkip
DoubleSkip
Seed cost ($/ac) $84.00 $56.28 $42.00 $42.00Yield (lb/ac) 964 1129 765 8312013 cotton price ($/lb) $0.90 $0.90 $0.90 $0.90Gross Income ($/ac) $868 $1,016 $688 $748Income - seed cost ($/ac) $784 $960 $646 $706% income of Solid 100% 122% 83% 90%Income over Solid ($/ac) - $176 (-$137) (-$78)
Economics at FARMER 2013
Item Solid Single SkipSeed cost ($/ac) $84 $56.28Yield (lb/ac) 939 10882013 cotton price ($/lb) $0.90 $0.90Gross Income ($/ac) $845 $979Income - seed cost ($/ac) $761 $923% income of Solid 100% 121%Income over Solid ($/ac) - $162
$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)
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.