Strip Till Systems for Burley Tobacco in Tennessee Paul Denton University of Tennessee
Objective Evaluate alternative strip till systems for burley tobacco production in Tennessee Compare these systems to no-till and fully tilled systems Conduct evaluations in the two major production regions
Tillage systems No till Narrow strip till Wide strip till Rototill strip till Wide strip till + rototill strip Full tillage One pass system with no till transplanter, narrow shank in front of planter shoe, in undisturbed soil One pass with narrow in row shank (6 in winged point) approximately 6 in deep, followed by no till transplanter One (HR) or two (GR) passes with in row subsoiler shank, with angled fluted coulters and rolling basket behind shank, approximately 12 inches deep, followed by transplanter One pass with narrow in row rototill unit, followed by transplanter One pass with in row subsoiler followed by one pass with narrow rototiller, followed by transplanter One pass with chisel plow, one or two passes with full width rototiller, followed by transplanter
Fertilizer Treatments 1. All fertilizer surface broadcast 2. Two-thirds of fertilizer surface broadcast, one-third banded beside row 210 lbs/ac N, as ammonium nitrate P and K by soil test
No-till No seedbed preparation prior to transplanting Transplanter contains coulter, narrow shank, weight
Strip-till Tobacco transplanted into a tilled strip ~30-45 cm wide Subsoiler shank with fluted coulters and rolling basket Narrow rototiller Narrow shank with closing disks
Prior cover: Procedures timothy/orchardgrass sod at Greeneville soybean residue at Highland Rim Soil types Dickson silt loam at Highland Rim Decatur loam/clay loam at Greeneville Weed control Greeneville Glyphosate burndown in fall Paraquat two weeks before transplanting Spartan and Command just before transplanting Poast after transplanting Weed control Highland Rim Burndown with Roundup in spring Devrinol and Spartan 2009; Prowl, Devrinol and Spartan 2010 Poast after transplanting
Procedures Varieties: Highland Rim: KT 206 LC both years Greeneville: KT 204 LC in 09, TN 90 LC in 10 Standard production practices Transplanted late May early June Dry in 2009 at HR, good growing seasons otherwise Harvest late August mid September
2009 Yields Highland Rim Banded Fertilizer No Banded Fertilizer Average* --------------------------- (lbs/ac) ----------------------------- No till 1992 1717 1854 b* Narrow ST 2134 2350 2241 a Rototill ST 2209 2264 2236 a Wide ST 2270 2295 2282 a Wide ST + Roto ST 2305 2207 2256 a Full Tillage 1983 2274 2128 a Average** 2134 2184 * Means followed by the same letter are not significantly different at P= 10% ** No significant difference in yield between fertilizer treatments
2009 Yields - Greeneville Banded Fertilizer No Banded Fertilizer Average* --------------------------- (lbs/ac) ----------------------------- No till 2855 2874 2864 Narrow ST 2976 2949 2912 Rototill ST 3070 2895 2983 Wide ST 2906 3118 3012 Wide ST + Roto ST 2946 2991 2968 Full Tillage 3008 3100 3054 Average* 2944 2988 * No significant difference in mean yields between treatments at P=10%
2010 Yields - Highland Rim No Banded Fertilizer --- (lbs/ac)--- No till 2805 c* Narrow ST 3016 bc Rototill ST 3239 ab Wide ST 3151 ab Wide ST + Roto ST 3250 ab Full Tillage 3354 a * Means followed by the same letter are not significantly different at P= 10%
2010 Yields - Greeneville Banded Fertilizer No Banded Fertilizer Average* --------------------------- (lbs/ac) ----------------------------- No till 3316 3274 3295 b* Narrow ST 3269 3193 3231 b Rototill ST 3201 3608 3404 b Wide ST 3307 3349 3328 b Wide ST + Roto ST 3341 3482 3411 b Full Tillage 3621 3820 3720 a Average** 3342 3454 * Means followed by the same letter are not significantly different at P= 10% ** No significant difference in yield between fertilizer treatments
Yield Across Years and Locations Tillage System Yield --- (lbs/ac)--- No till 2709 c* Narrow ST Rototill ST Wide ST 2859 b 2965 ab 2943 ab Wide ST + Roto ST 2971 ab Full Tillage 3064 a * Means followed by the same letter not significantly different at P = 0.10.
Soil Residue Cover GREC 6/22/09 Tillage System % Residue Cover No till 41 Narrow ST 29 Rototill ST 14 Wide ST 7 Wide ST + Roto ST 4 Full Tillage 4
Conclusions Strip till with a subsoiler shank or rototiller appears to be essentially equal to full tillage use of rototiller after subsoiler same as two passes with subsoiler Narrow strip till with single pass Sometimes gave lower yield than wider strip till Likely impractical due to difficulty of transplanting No-till yields tend to be lower than tilled works better in well-drained, well structured soils
Conservation Tillage for Burley? Strip till equal to full tillage, no-till lags in yield No till works better on well structured soils Requires more management than tilled Weed control Good control possible with herbicides alone Still likely to require some hand weeding Proper transplant depth and good root ball - soil contact are critical Soil conditions at tillage and transplanting time Properly adjusted and operated equipment Low residue cover a concern with early burndown and aggressive strip till