|Porter, D - TEXAS A&M UNIVERSITY|
Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: November 1, 2003
Publication Date: November 6, 2003
Citation: Acosta Martinez, V., Upchurch, D.R., Porter, D. 2003. Impacts of cotton and peanut cropping systems on microbial biomass, community structure, and enzyme activities of a sandy soil. American Society of Agronomy Meetings. Technical Abstract: The impacts of the first two years of cotton (Gossypium hirsutum L.) (=Ct) and peanut (Arachis hypogaea L.) (=Pt)cropping systems on a Brownfield fine sandy soil (Loamy, mixed, superactive, thermic Arenic Aridic Paleustalfs) were investigated. This research was conducted near Seminole in West Texas. The soil contains 91 percent sand, 2 percent silt and 7 percent clay. Samples (0-12cm) were taken in March, June, and September 2002, and March 2003 from PtPtPt under 75 percent evapotranspiration (ET) irrigation, and CtCtPt and PtCtCt under 50, 75 and 100 percent ET irrigation treatments. Total soil N and aggregate stability were not significantly affected by cropping systems. The soil pH was >8.0, and was lowest in PtPtPt. Soil organic C and the activities of b-glucosidase, b-glucosaminidase, acid phosphatase, alkaline phosphatase and phosphodiesterase increased in PtPtPt in comparison to CtCtPt and PtCtCt. The intracellular and total arylsulfatase activities showed the same trend, but the extracellular arylsulfatase activity was unaffected by the cropping systems. Soil microbial biomass C (Cmic) showed different seasonal variation than enzyme activities, but it was also highest in PtPtPt. PCA showed differences in fatty acids methyl ester (FAME) profiles due to time of sampling, and MANOVA showed fungi indicator fatty acids (18:2w6c and 18:1w9c) were dominant in PtPtPt.