Influence of long-term manure application on mineral composition of irrigated barley silage

Abstract

Miller, J. J., Beasley, B. W., Drury, C. F., Larney, F. and Hao, X. 2015. Influence of long-term manure application on mineral composition of irrigated barley silage. Can. J. Plant Sci. 95: 759–770. The long-term effect of land application of manure type (composted vs. stockpiled manure), bedding type (wood-chips vs. straw), and application rate on feed quality of barley silage as feed for beef cattle is unknown. We measured selected minerals [P, Ca, Ca:P ratio, Mg, K, K:(Ca+Mg) ratio, Na, Fe, Mn, Zn, Cu] of irrigated barley silage (Hordeum vulgare L.) on a clay loam soil after 4 (2002), 7 (2005) and 11 (2009) years of annual applications of composted (CM) or stockpiled (SM) feedlot manure with wood-chips (WD) or straw (ST) bedding at three application rates (13, 39, 77Mg ha−1 dry wt.). The treatments also included an unamended control and inorganic fertilizer treatment. Manure type generally had inconsistent or no significant (P≤0.05) effect on the concentrations of these minerals in barley silage. Most crop minerals were generally greater under ST than WD. The findings for P, K, Na, and K:(Ca+Mg) ratio generally supported our hypothesis of greater crop concentrations with greater application rate, but Ca and Mg decreased at higher rates. Overall, our findings suggest that bedding and application rate have more potential than manure type for managing the feed quality of barley silage.