Submitted to: Inter-American Sugar Cane Seminars Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: October 5, 2000
Publication Date: December 5, 2000
Citation: Morris, D.R., Tai, P.Y. 2000. Characteristics of sugarcane rhizosphere under flooding. Inter-American Sugar Cane Seminars Abstracts. P.5. Technical Abstract: Organic soil in the Everglades Agricultural Area have been reported to be subsiding mostly from microbial oxidation. An experiment was conducted at Canal Point, FL to investigate the rhizosphere microbial populations and chemistry as affected by sugarcane varieties under flooded conditions. Five sugarcane varieties were grown outside under three water table levels in 38 L containers consisting of a mixture of sand and organic soil. At harvest, stalks were cut at soil surface level, and soil samples were taken from upper (A) and lower depths. Microbial counts and chemistry were analyzed. Correlations between plant yield and rhizosphere parameters showed there was a negative correlation with TOC (total organic carbon) levels in the upper soil. It appears that plants that lose more soluble carbohydrates around their root systems have lower sugar yields. Microbial populations were generally low. The low number of microorganisms may have been due to the high soil pH encountered in these soils. TOC had a positive effect on bacterial populations in the rhizosphere, while actinomycetes were influenced by water table treatment. Fungi were not influenced by either water table or cultivar. Available N and P in the rhizosphere were not affected by cultivar or water. Our data indicated that TOC in the rhizosphere is an important variable related to both crop yield and bacterial populations. Future research will be required to quantify those relationships.