|Johnson, Richard - TEXAS TECH UNIVERSITY|
Submitted to: Journal of Cotton Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 22, 2003
Publication Date: October 6, 2003
Citation: BAUER, P.J., REEVES, D.W., JOHNSON, R.M., BRADOW, J.M. COVER CROP, TILLAGE, AND N RATE EFFECTS ON COTTON GROWN IN ULTRA-NARROW ROWS. CROP MANAGEMENT. 2003. Online. (doi:10.1094/CM-2003-1006-01-RS). Interpretive Summary: A potentially new way of growing cotton, in rows widths of 10 inches or less (called ultra-narrow row), has attributes that fit well with soil-saving conservation tillage production practices. In order to help assess this new practice for cotton growers, we studied how tillage, winter cover crops, and fertilizer nitrogen rates affect fiber quality of ultra-narrow-row cotton. We found that the soil management systems (tillage systems and cover crops) and N rates did not have a large effect on fiber quality. Our study did indicate, though, that poor fiber quality with this system could result when seeding rates were extremely high. Seeding into a heavy residue cover (as in cover crop systems) often necessitates over-seeding so that adequate plant stands are achieved. The results indicate that planters should be carefully calibrated to avoid extreme plant populations and perhaps low fiber quality. These results are important to scientist studying this new production practice and to growers who are considering converting to this way of growing cotton.
Technical Abstract: Fiber quality is a major concern for cotton (Gossypium hirsutum L.) grown in row widths of 25-cm or less for both producers and processors. The objective of this field study was to determine the effect of winter cover, tillage, and N rate on fiber properties of cotton grown in 20-cm row widths. Experiments were conducted near Auburn, AL [Compass loamy sand (coarse-loamy, siliceous, subactive, thermic Plinthic Paleudult)] and near Florence, SC [Wagram sand (loamy, siliceous, thermic Arenic Paleudult)] in 1996 and 1997. Treatments were winter cover (cereal, legume, and fallow), tillage (conventional and conservation) and N rate (0, 45, 90, and 135 kg/ ha). The legume winter cover was white lupin (Lupinus albus L.) at Auburn and winter pea (Pisum sativum L.) at Florence. Black oat (Avena strigosa Schreb.) was the cereal winter cover at Auburn in 1996 and both years at Florence. In 1997 at Auburn, a black oat/rye (Secale cereale L.) mixture was used. Cotton was stripper-harvested at Auburn and hand-harvested at Florence. As N rate increased, bolls per plant and fiber yellowness (Hunter's +b) tended to increase; otherwise, residue management and N rate did not consistently affect plant characteristics (plant height, first fruiting node, and bolls per plant), boll characteristics (lint per boll and lint percent), or fiber properties. Micronaire readings and secondary wall characteristics of the fiber grown in Auburn were unacceptably low in both years (average micronaire reading was 2.9 units in 1996 and 2.8 units in 1997). This was attributed to exceedingly high plant populations. The data suggest that residue and N management have little effect on fiber properties of cotton grown in narrow-row systems.