Submitted to: Soil Science Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 11/30/2002
Publication Date: 11/30/2002
Citation: GREEN, V.S., STOTT, D.E. IMPACT OF HIGH SOIL PHOSPHORUS LEVELS ON SOIL BIOLOGICAL ACTIVITY AND PHYSICAL PROPERTIES OF OXISOLS. CD-ROM. INDIANAPOLIS, IN: SOIL SCIENCE SOCIETY OF AMERICA ANNUAL MEETING. 2002. Interpretive Summary:
Technical Abstract: For the Cerrado region of Brazil to be agriculturally productive, large amount of P fertilizer must be added to overcome the P-fixation capacity of these Oxisol soils. Additions of large amounts of fertilizer affect the chemistry of the soil and may affect the soil physical and biological properties. The effect of different amounts of fertilizer P on soil physical and biological properties on limed and unlimed Oxisol soils was examined. Our objective was to determine the effect of liming and P- additions on important physical and biological properites. We incubated limed and unlimed soils for 36 week after additions of P fertilizer (Ca(H2PO4)2). The effects of liming and P additions were most pronounced on soil enzyme activities. Liming decreased the activity of beta-glucosidase and acid phosphatase while it increased the acitivity of arylulfatase. Additions of P increased the activity of beta-glucosidase while it decreased the activity of acid phophatase and arylsulfatase. Liming and P additions decreased water dispersible clay but did not affect aggregate stability. Liming also increased C mineralzation. Lime and P-fertilizer can apparently be used without adverse impacts on the physical properties of Oxisols. However, high P additions appear to be stimulating natural C-cycling, but suppressing natural S- and P-cycling in these Oxisols. Thus, although instituting no-till management in these soils will preserves much of the C, there might be a slight decline due to the fertilizer management.