Author
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Balkcom, Kipling |
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Duzy, Leah |
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Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings Publication Acceptance Date: 1/19/2012 Publication Date: 5/1/2012 Citation: Balkcom, K.S., Duzy, L.M. 2012. Sidedress nitrogen rates and costs for Southeastern cotton production. In: Boyd, S., et al., editors. In: Proceedings of the National Cotton Council Beltwide Cotton Conference, Jan. 3-6, 2012, Orlando, Florida. p. 1379-1383. Interpretive Summary: Nitrogen (N) is typically the most important fertilizer input for cotton (Gossypium hirsutum L.), and usually ranks in the top five production expenses for cotton. Previous N recommendations have been based on conventional tillage practices that do not include cover crops. Our objective was to determine cotton response to N following a non-fertilized and fertilized cover crop. An experiment was initiated by scientists from the National Soil Dynamics Laboratory at the Wiregrass Research and Extension Center in Headland, AL during the 2006-2008 growing seasons. A traditional cotton N response trial was conducted following a non-fertilized cover crop with three additional treatments consisting of split applications for the 90 lb N ac-1 rate. This trial was embedded on the 0 N plots, and examined time of application, N source, and N rate for a cover crop. All corresponding eight row cotton plots that received N fertilizer on the cover crop were split with four rows receiving 90 lb N ac-1 at sidedress, while the other four rows were not fertilized. Nitrogen rates for cotton following the non-fertilized cover crop indicated that 30 lb N ac-1 applied at planting followed by 60 lb N ac-1 at sidedress was consistently effective for maximum lint yield across all three growing seasons. Cotton grown following a cover crop fertilized with 30 lb N ac-1 or 1 ton poultry litter ac-1 consistently produced maximum yields with 90 lb N ac-1 applied at sidedress across all three years of the study. The results indicate that cotton following high residue cover crops may not always require N fertilizer above currently recommended rates to maximize yields. Technical Abstract: Nitrogen (N) is typically the most important fertilizer input for cotton (Gossypium hirsutum L.), and usually ranks in the top five production expenses for cotton. Previous N recommendations have been based on conventional tillage practices that do not include cover crops. Our objective was to determine cotton response to N following a non-fertilized and fertilized cover crop. This experiment was conducted at the Wiregrass Research and Extension Center in Headland, AL during the 2006-2008 growing seasons. A traditional cotton N response trial was conducted following a non-fertilized cover crop with three additional treatments consisting of split applications for the 90 lb N ac-1 rate. This trial was embedded on the 0 N plots, and examined time of application, N source, and N rate for a cover crop. All corresponding eight row cotton plots that received N fertilizer on the cover crop were split with four rows receiving 90 lb N ac-1 at sidedress, while the other four rows were not fertilized. Nitrogen rates for cotton following the non-fertilized cover crop indicated that 30 lb N ac-1 applied at planting followed by 60 lb N ac-1 at sidedress was consistently effective for maximum lint yield across all three growing seasons. Cotton grown following a cover crop fertilized with 30 lb N ac-1 or 1 ton poultry litter ac-1 consistently produced maximum yields with 90 lb N ac-1 applied at sidedress across all three years of the study. This data represents multiple growing seasons but only one variety and one soil type; however, the results indicate that cotton following high residue cover crops may not always require N fertilizer above currently recommended rates to maximize yields. |
