EFFECT OF CROP ROTATION AND TILLAGE SYSTEMS ON SOIL MICROBIAL COMMUNITY

Authors: FENG, Y - AUBURN UNIVERSITY; Reeves, Donald; JI, P - AUBURN UNIVERSITY

Submitted to: American Society of Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 9/30/2003
Publication Date: 2/11/2003
Citation: Feng, Y., Reeves, D.W., Ji, P. Effect of crop rotation and tillage systems on soil microbial community. American Society of Agronomy Abstracts. 2003. CD ROM. Denver, CO.

Interpretive Summary:

Technical Abstract: In spite of the agronomical and ecological benefits of crop rotation and conservation tillage, cotton (Gossypium hirsutum L.), the dominant crop in the southeastern USA, is generally grown in continuous monoculture due to the profitability. The specific impacts of crop rotation and tillage on soil microbial communities are still largely unknown. We established a study on a Compass sandy loam to compare an intensive cotton cropping system, maximizing the production of crop residues and legume nitrogen inputs, to a standard cotton production system under conventional and conservation tillage. The intensive system included sunn hemp and ultra-narrow row cotton in rotation with wheat (Triticum aestivum L.) and corn (Zea mays L.). The standard system included continuous cotton of standard row width (100-cm) and cereal cover crops. Soil samples were collected at 0-5, 5-10, 10-20, and 20-30 cm depth increments. Compared to the conventional tillage treatment, conservation tillage increased soil organic C and total N, microbial biomass C and N, and basal respiration at the 0-5 cm depth increment, but not the total phospholipids fatty acid (PLFA) contents. All these parameters under conservation tillage showed more pronounced decreases with soil depth than those under conventional tillage. Treatment differences among cropping systems were not consistent. Differences in soil microbial communities as indicated by PLFA profiles will be assessed.