|Reddy, K. Chandra|
Submitted to: Symposium Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 5/5/2007
Publication Date: 7/15/2007
Citation: Sainju, U.M., Senwo, Z.N., Nyakatawa, E.Z., Tazisong, I.A., Reddy, K. 2007. Tillage, cover crop, and nitrogen fertilizer source effects on soil carbon and nitrogen sequestration. In: A. Chabbi (ed.) Proc. International Symposium on Organic Matter Dynamics in Agro-Ecosystems. July 16-19, 2007. Poitiers, France. p. 446-447. Interpretive Summary:
Technical Abstract: The 10-yr effect of combinations of tillage (no-till, mulch till, and conventional till), cover crop (rye vs. none), and N fertilization source and rate (0 and 100 kg N ha-1 from NH4NO3 and 100 and 200 kg N ha-1 from poultry manure) was evaluated on crop residues and soil organic C (SOC) and organic N (SON) contents at the 0-20 cm depth in northern Alabama, USA The amount of crop residue returned to the soil increased with N fertilization from NH4NO3 and poultry manure, regardless of tillage or cover crop. While SOC and SON were not influenced by treatments at 10-20 cm, they were 12 to 21% greater in rye and N fertilization with or without tillage than in no rye and N fertilization with conventional tillage at 0-10 cm. To a depth of 20 cm, SOC and SON contents were 23-25% greater with cropping than with bare fallow and 8-19% greater with poultry manure than with 0 and 100 kg N ha-1 from NH4NO3. While tillage had minimum impact, long-term N fertilization from inorganic N fertilizer or poultry manure with rye cover cropping increased C and N sequestration, indicating improved soil quality and productivity.