CHANGES IN CENTRAL ALABAMA COTTONSOIL MANAGEMENT, 1991 AND 2001

摘要

In 1991, 36 random cotton fields were surveyed in Autauga and Elmore Counties in Central Alabama. In 2001, these samefields were revisited along with 32 additional fields. The 2001 survey included soil samples at 3 depths and field andcropping conditions. In spite of a dramatic shift toward conservation tillage in the past decade (56% conservation tillage in2001 versus none in 1991), traffic pans remain a potential yield-limiting factor in cotton fields of Central Alabama.Increased use of paratilling and in-row subsoiling has not eliminated the presence of traffic pans within the surface 12 inchesof soil. This situation is aggravated by poor overall soil quality as indicated by very low soil organic matter (mean=0.6%).Cover crops are used on only 15% of the fields in 2001. In general, soil fertility does not appear to be a limiting factor incotton production. Most fields sampled had optimum soil pH and high P and K in the surface 8 inches of soil. While theextractant used for micronutrients and metals is not ideally correlated with plant availability, it does provide some indicationthat micronutrient availability and metal contamination of cotton fields is not a major concern at this time.