Submitted to: Agronomy Journal
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/1/2003
Publication Date: 3/1/2004
Citation: Sistani, K.R., Rowe, D.E., Johnson, J., Tewolde, H. 2004. Supplemental nitrogen effect on broiler-litter fertilized cotton. Agronomy Journal. 96:806-811. Interpretive Summary: Increasing nitrogen fertilization of cotton crop may not always be desirable because production problems occur when nitrogen supply exceeds the crop requirement. The quantity of nitrogen needed from broiler litter or combination of litter and chemical fertilizer for optimum cotton yield production need to be investigated. Four inorganic supplemental nitrogen rates of 0, 30, 60, and 90 pound/acre as side dress in addition to one ton/acre litter were tested during 2000-02 growing seasons. The supplemental N application did not impact the cotton yield in two out of three years. In 2000 growing season, cotton yield was significantly greater for 0 and 30 than 60 and 90 lb/acre rates. No yield increase was observed by increasing the supplemental N rate up to 90 lb/acre. Results indicated that because of long term litter application, the one ton/acre broiler litter application to all plots prior to planting each year proved to be adequate in three consecutive years for optimum cotton production under a no-till system. This will impact the cotton farmers for better nitrogen management of their crop particularly if they are using litter as a source of nutrients for cotton production.
Technical Abstract: Nitrogen (N) nutrition plays a critical role in cotton (Gossypium hirsutum L.) production. However, increasing N fertilization may not always be desirable because production problems occur when N supply exceeds the crop requirement. A field experiment was conducted during 2000-02 to study the optimal quantity of N needed from litter or combination of litter N and supplemental inorganic N for optimum cotton yield production. Poultry litter (2.24 Mg ha-1 equivalent to 1 ton/acre) has been applied to the site annually for the past 20 years and continued during the life of this study. The experiment included 4 inorganic N rates (0, 34, 67, and 101 kg N ha-1) as side dress after planting. The smallest overall average cotton seed yield of 562 kg ha-1 was obtained during 2000 (an exceptionally dry year) followed by 1551 kg ha-1 in 2001, and 880 kg ha-1 in 2002, which basically followed the precipitation pattern during those years. The supplemental N application did not impact the cotton yield in two out of three years. In the 2000 growing season, cotton yield was significantly greater for 0 and 34 than 67 and 101 kg N ha-1 rates. This indicates the negative effect of excess N application on cotton yield under drought conditions. However, under more favorable soil moisture conditions, no significant yield differences were observed by increasing the supplemental N rate up to 101 kg N ha-1. The 2.24 Mg ha-1 broiler litter application to all plots prior to planting each year provided approximately 80 Kg N ha-1, which proved to be adequate in three consecutive years for optimum cotton production under a no-till system.