Submitted to: Soil & Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/19/2002
Publication Date: N/A
Interpretive Summary: Much of the row-crop agriculture in the southeastern USA is still conventionally tilled and fertilized unlike other parts of the country where conservation tillage is increasingly being adopted. The principle of conservation tillage is to keep crop residue or a cover crop on the soil all year round. This residue holds the soil together and lets water soak into the ground. Conservation tillage benefits the farmer and the environment in several ways including improved soil and water conservation and reduced production costs while improving yields and profits. Cotton is a dominant crop in the southeast and only a small percentage is under conservation tillage. A big poultry industry produces huge amounts of poultry litter, a potentially good fertilizer, in the Southeast. In four years of research near Watkinsville, GA, lint yield from no-till cotton exceeded that from the conventionally-tilled cotton by 23%. Poultry litter rproduced 11% more lint than ammonium nitrate. Yield from no-till cotton fertilized with poultry litter exceeded that from conventional tillage fertilized with ammonium nitrate by 34% (729 versus 977 lb/acre). Drought in the fourth year eliminated yield differences. By adopting no-till and fertilizing with poultry litter, cotton production in the Southeast would increase and an additional outlet for the poultry litter would be created.
Technical Abstract: The southeastern USA has generally lagged behind the Great Plains states in adoption of conservation tillage. cotton (Gossipium hirsutum L.) is a dominant crop in the southeast and only about 12% of the 620,000 hectares, in Georgia, for example, is under conservation tillage. Georgia and bordering states produce about 42% of the poultry in the United States. In Georgia alone, over 1.6 million Mg of poultry litter is produced annually. Poultry litter is well-recognized as a fertilizer but its use in crop land is limited in the southeast. In research from 1996 to 1999, cotton followed by rye (Secale cereale L.) cover crop were grown under a factorial arrangement of tillage (no-till [NT] vs conventional tillage [CT]) and fertilizer (ammonium nitrate as conventional fertilizer [CF], vs poultry litter [PL]) on a Cecil sandy loam (Clayey, kaolinitic thermic Typic Kanhapludult) near Watkinsville, Georgia. Differences in average lint yield were: 34% for NTPL over CTCF (P=0.001), 20% for NTPL over CTPL (P = 0.013), and 27% for NTCF over CTCF (P = 0.005). NT produced 23% more lint than CT (P=0.001). Due to drought, there were no differences in yield in the fourth year. By adopting no-till and fertilizing with poultry litter, cotton production in the Southeast would increase and an additional outlet for the poultry litter would be created.