Cotton (Gossypium hirsutum L.) has been the main agronomic crop in northeast Louisiana for many years. However, intensive agricultural production paired with mono-cropping has resulted in decreased productivity and declining soil quality. The implementation of best management practices has the potential to alleviate many of these problems. Information is limited on the benefit of these conservation practices on these highly degraded soils. Therefore, a field trial to evaluate the effect of poultry-litter applications on cotton production and the environment was established. Trials were conducted at the Macon Ridge Research Station in Winnsboro, LA from 2008 to 2011. Poultry litter was applied at the rate of 0, 3.3, and 6.7 mg ha-1. The effect of litter applications was evaluated over both conservation and conventional tillage systems with and without a winter cover crop. Additionally, to simulate traditional production practices, an inorganic fertilizer treatment was included. Cotton lint yields of the poultry-litter treatments were significantly (P < 0.05) higher than those that received inorganic fertilizers, yielding 231, 175, 392, and 330 kg lint ha-1 more for poultry-litter applied plots compared to inorganic fertilizers in 2009, 2010, 2011, and 2012, respectively. However, the application of 6.7 mg ha-1 did not significantly improve yields over the 3.3 mg ha-1 rate. A significant buildup of Mehlich-3 extractable, soil test P level was found when poultry litter was applied compared to inorganic fertilizers, with increased soil test P levels of 26 mg P kg-1 by the end of the trial. Overall, poultry litter can be used as a soil amendment in northeast Louisiana; nonetheless, management that enhances yield benefits while minimizing soil accumulation needs to be emphasized to minimize increased soil P buildup.
