|Novak, Jeffrey - Jeff|
Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Abstract Only
Publication Acceptance Date: 1/9/2007
Publication Date: 1/9/2007
Citation: Bauer, P.J., Frederick, J.R., Novak, J.M., Busscher, W.J. 2007. Yield variability in conventional and conservation tillage [abstract]. p. 531. 2007 Beltwide Cotton Conference, 9-12 January 2007, New Orleans, Louisiana. CDROM.
Technical Abstract: Spatial variability can be quite large for cotton (Gossypium hirsutem L.) yield on coastal plain soils of the Southeast USA. A substantial amount of the variability is caused by differences in soils for water availability. Since tillage management can affect soil available water, our objective was to determine the influence of tillage on variability of cotton yield and fiber quality. In 1998, a fourteen acre field containing 7 different soils was divided roughly in half, with half of the field managed with conservation tillage and half managed with conventional. Corn was grown in 1999, 2001, and 2003. Cotton was grown in 2000, 2002, and 2004. Soil test values of pH and K were determined on soil samples collected at 50-ft grid points throughout the entire field (soil test data are reported for 2004 only). Cotton fiber properties were determined on samples collected at the same grid points. Yield was measured with yield monitors. Variability for soil test values of pH and K within soil map unit was significant for both tillage systems. Among soil map units, the range of average soil test values was lower for conservation tillage than for conventional tillage. Correlations between soil test values and yield or fiber properties were weak or not significant. Averaged over all three years, there was little variation for cotton fiber properties among soil map units in both tillage systems. Yield, on the other hand, exhibited considerable variation among soil map units for both cotton and corn. There was considerable within-field variability for yield of both crops. Across soil map units, cotton yields (averaged over the three years) ranged from about 450 lbs to about 700 lbs lint per acre. Corn yields ranged from 105 to 120 bushel per acre. Tillage did not have a significant impact on within-field variability. The results suggest that for similar coastal plain soils, cotton spatial management emphasis should be on yield. Yield response of the corn and cotton to soil map unit was quite different indicating spatial management practices need to be crop specific on these soils.