Tillage, cover cropping, and poultry litter effects on cotton: II. Growth and yield parameters

The development of conservation tillage systems for cotton (Gossypium hirsutum L.), capable of reducing soil erosion and improving soil quality while increasing yields and profits, remains a challenge in the southeastern USA. Poor emergence and growth, delayed maturity, and reduced yield are some of the problems that have been encountered in the use of conservation tillage on cotton. The objectives of this study was to evaluate the effects of tillage (no-till, mulch-till, conventional till), cropping system [cotton-winter fallow, cotton-winter rye (Secale cereale L.) cover crop] and N source (poultry litter, ammonium nitrate) on growth and yield of cotton from 1996 to 1998 in northern Alabama. In 1997, cotton lint yield under no-till (NT) was 24 and 18% greater than that under conventional fill (CT) and mulch-till (MT) systems, respectively. In 1998, cotton lint yield under the NT system was 7% greater than that under CT. Poultry litter (PL) at 100 kg N ha(-1) gave similar lint yield to ammonium nitrate (AN), whereas at 200 kg N ha(-1), lint yields were significantly greater. No-till, cotton-winter rye cropping, and surface application of 200 kg N ha(-1) in form of PL conserved soil moisture in the top 7 cm of the soil. This resulted in early seedling emergence, high seedling vigor, good plant growth, and high lint yield of cotton. These treatments would be appropriate for use in the southeastern USA where soil erosion is a problem and plenty of PL is available each year from the poultry industry.