Submitted to: Nutrient Cycling in Agroecosystems
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/5/2007
Publication Date: 10/18/2007
Citation: Sistani, K.R., Adeli, A., Tewolde, H., Brink, G.E. 2007 Broiler chicken litter application timing effect on coastal bermudagrass in southeastern u.s.. Nutrient Cycling in Agroecosystems. 81:49-57 Interpretive Summary: In many states swine effluent application timing is regulated and limited to spring and summer months. In contrast, poultry litter application timing is not regulated; hence it is being surface land applied year-round in many states. It is expected that soon, litter application during the winter months or rainy months will be prohibited. Therefore, producers have to store litter for application during spring and summer. In this study, we attempted to identify an optimum date or dates for litter application that maximizes nutrient availability and uptake to crops and minimizes nutrient buildup in soil or losses through runoff. All the litter application dates did not influence coastal bermudagrass dry matter yield and nutrient uptake except for nitrogen. The residual buildup of carbon, which is a beneficial impact, and the phosphorus, copper, and zinc with potential negative impact were observed with all litter application timings. We were expecting that late summer and early fall litter application to bermudagrass would be less efficient than early spring and early summer application dates, but high soil fertility level at the study site and climatic factors may have impacted the costal bermudagrass growth, which confounded the real response to litter application timing.
Technical Abstract: Presently, most of boiler litter is being applied to pasture lands year-round. This practice results in nutrient losses and potentially unfavorable environmental impacts particularly during the wet winter months. A two-year field plot experiment was conducted in 2001 and 2002 on Ruston silt loam in Mize, Mississippi to identify the optimum application timing that enhances litter nutrient availability to the crop while minimizing undesirable nutrient buildup in soil. Seven treatments (litter application timings) were employed on previously established costal bermudagrass plots. For each treatment, total litter needed was calculated based on 400 kg N ha-1 for top bermudagrass yield production, and applied either as single, two-way split, or three-way split at different dates as follow: May; May/June; April/May/June; May/June/July; June/July/August; July/August/September; and August/September/October. Bermudagrass was harvested 4 to 6 times each year for dry matter (DM) and nutrient uptake determination. No significant differences in DM yield were observed among seven litter application timings. The P uptake by coastal bermudagrass averaged about 60 kg ha-1 for all litter application timings. Significant differences were observed among litter application timings with regard to soil concentration of Ca, K, Cu, Fe, and Zn elements. Except for Fe and Mn, there were significant increases in soil nutrients compared to initial soil concentration of these elements. In general, summer and early fall litter applications resulted in greater buildup of most of these elements. Based on the results of this study, there is a wide window of timing for litter application on pasture without a great impact on litter nutrient availability, uptake, or residual buildup in soil.