Submitted to: Soil Science Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 11/5/2001
Publication Date: 11/5/2001
Citation: Potter, R.L., Meyer, J.L., Lowrance, R.R. 2001. Landscape factors explain riparian buffer efectiveness in the lower coastal plain. Agronomy Abstracts p. 380.
Technical Abstract: Riparian buffers are effective in removing groundwater nitrate exiting agricultural fields when much of the nitrate moves in shallow groundwater through the root zone of the buffer. It would be useful for conservation planning to have relatively simple relationships that describe the potential nitrate removal function. A study of seven sites in the lower Coastal Plain of Georgia suggests landscape factors that estimate sink/source relationships explain more variation in buffer effectiveness than soil biological or physical characteristics. Buffer effectiveness was estimated as extractable nitrate in the soil profile near the stream as a surrogate of the amount of N that may reach aquatic systems. Soil biological properties included microbial biomass C and N, soil C and N, root biomass and C and N, extractable ammonia and nitrate, and denitrification.. Physical properties included bulk density, water filled pore space, and pH. Multiple regression models yielded low (less than 40%) explanatory power for denitrification or profile nitrate based on soil biological and physical properties. Landscape factors were buffer width, length of upland slope, and the ratio of these. Using only these factors yielded coefficients of determination over 80%. This suggests that sink/source relationships may be an important factor determining buffer effectiveness.