%0 Journal Article
%T Cover Crop Biomass Harvest Influences Cotton Nitrogen Utilization and Productivity
%A F. Ducamp
%A F. J. Arriaga
%A K. S. Balkcom
%A S. A. Prior
%A E. van Santen
%A C. C. Mitchell
%J International Journal of Agronomy
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/420624
%X There is a potential in the southeastern US to harvest winter cover crops from cotton (Gossypium hirsutum L.) fields for biofuels or animal feed use, but this could impact yields and nitrogen (N) fertilizer response. An experiment was established to examine rye (Secale cereale L.) residue management (RM) and N rates on cotton productivity. Three RM treatments (no winter cover crop (NC), residue removed (REM) and residue retained (RET)) and four N rates for cotton were studied. Cotton population, leaf and plant N concentration, cotton biomass and N uptake at first square, and cotton biomass production between first square and cutout were higher for RET, followed by REM and NC. However, leaf N concentration at early bloom and N concentration in the cotton biomass between first square and cutout were higher for NC, followed by REM and RET. Seed cotton yield response to N interacted with year and RM, but yields were greater with RET followed by REM both years. These results indicate that a rye cover crop can be beneficial for cotton, especially during hot and dry years. Long-term studies would be required to completely understand the effect of rye residue harvest on cotton production under conservation tillage. 1. Introduction Nitrogen is the most difficult nutrient to manage when growing cotton. About 5,445,749£¿ha of the cotton were planted in the USA in 2003 [1]. Applying optimum N rates is necessary to maximize economic yields and minimize the negative impacts that N overapplication can have on the crop and environment [2]. Higher N rates than required can result in excessive vegetative growth which increases the proportion of immature bolls, reduces lint quality and cotton yields, and increases disease and insect damage [3¨C6]. However, N deficiencies can reduce vegetative and reproductive growth and decrease yields [3]. Many parameters combine to determine the optimum N rates for cotton, such as soil type, location, N application method, tillage system, water availability, use of winter cover crops, and potential yield [7]. Conservation systems for cotton production in the southeastern US have increased in adoption to approximately 50% of the 2.9£¿million£¿ha planted in this area [8]. The use of winter cover crops has been well documented as an effective method for improving soil chemical, biological, and physical properties [9, 10]. Among winter crop species, winter cereals like rye can have many benefits because they produce high amounts of biomass, are easy to establish and kill, and provide good ground cover during the winter [8, 11]. However, the
%U http://www.hindawi.com/journals/ija/2012/420624/