Submitted to: Southern Conservation Tillage Systems Conference
Publication Type: Proceedings
Publication Acceptance Date: 6/27/2006
Publication Date: 6/27/2006
Citation: Watts, D.B., Torbert III, H.A., Prior, S.A., Balkcom, K.S. 2006. Tillage affects on n mineralization and losses of winter applied manure. In: Schwartz, R. C., Baumhardt, R.L., and Bell, J.M., editors. Proceedings of the 28th Annual Southern Conservation Systems Conference. Improving Conservation Technologies to Compete for Global Resources and Markets. June 26-28, 2006, Bushland, Texas. p. 196-204. Interpretive Summary: Information is needed on how conservation practices affect nitrogen loss after winter application of manure. Thus, this study investigated nitrogen loss from manure during the winter in conventional tillage and no-tillage systems. Dairy manure was applied in the fall. The amount of nitrogen in manure used by plants was measured. More nitrogen was found under conventional tillage at the beginning, but declined over the growing season. The no-tillage system retained more manure nitrogen and had the highest plant biomass production. This information shows that winter application of manure in no-tillage systems could reduce N loss to the environment.
Technical Abstract: A better understanding is needed of how conservation practices affect the concentration of soil N resulting from winter application of manure. This study was conducted to evaluate the effects of manure applications on the mineralization and concentration of N during the winter. The experiment was established in fields that were previously under conventional and conservation tillage with and without manure application. Dairy composted manure was applied annually in the fall prior to planting of a winter cover crop. The quantification of N released from composted manure and the amount of N uptake by plant tissues of the cover crop during winter months was determined. The concentration of N was higher in the conventional tillage plots at the beginning of the study and quickly diminished throughout the growing season. The conservation tillage plots with manure retained the most N compared to the other treatments. This treatment also had the highest plant biomass compared to the other treatments, indicating much more was retained in the plant tissues. These results show use conservation tillage in conjunction with cover crops when applying manure in winter months could potentially minimize the amount of N lost.