|Karlen, Douglas - Doug|
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/12/2006
Publication Date: 1/10/2007
Citation: Gibson, L.R., Nance, C.D., Karlen, D.L. 2007. Winter triticale response to nitrogen fertilization when grown after corn or soybean. Agronomy Journal. 99:49-58. Interpretive Summary: Incorporation of an additional crop into the current two-year corn-soybean rotation could have many agronomic and environmental benefits. Previous research showed that triticale (a cross between rye and wheat) that has high lysine content would be an excellent candidate. Triticale can be incorporated into the traditional corn-soybean rotation and used as a cover crop, for grazing, for silage or hay, or grain and straw production. It could also be grown as a feedstock for bioenergy production. This research was conducted to determine the response of triticale to various nitrogen (N) fertilizer rates when grown after either corn or soybean in Iowa. We found that following either crop, triticale forage and grain yields were maximized with 33 kg/ha (30 lbs/acre) of nitrogen) fertilizer. Our results are important for farmers, conservationists, crop consultants, and policy makers interested in creating more sustainable agriclutural production enterprises throughout the Midwest.
Technical Abstract: Winter triticale (XTriticosecale Wittmack) could be more widely grown as a forage, grain, or cover crop in the U.S. Corn and Soybean Belt, but research needed to establish best management practices is limited. This study was conducted to determine the amount of nitrogen (N) fertilizer needed to optimize triticale productivity and to quantify the amount of N taken up following either corn silage (Zea mays L.) or soybean (Glycine max (L.) Merr.). The response of winter triticale grown near Ames and Lewis, Iowa, to four N fertilization rates (0, 33, 66, 99 kg N ha-1) applied in mid-March was evaluated for the 2003-2004 and 2004-2005 growing seasons. Maximum dry matter and grain yields were produced with 33 kg N ha**-1 at Ames and no N fertilization at Lewis. Maximum N concentrations of triticale dry matter were generally produced with 99 kg N ha**-1. Nitrogen uptake by winter triticale was mostly complete by early May and was 39 to 133 kg ha**-1 without N fertilization. Nitrogen uptake increased with each 33 kg ha**-1 increment of additional N fertilizer, totaling 98 to 192 kg ha**-1 for 99 kg N ha**-1. The results of this study suggest forage and grain yields of winter triticale grown after corn silage or soybean in the Midwestern U.S. can be maximized by applying 33 kg ha-1 N fertilizer. For N rates of 0 to 90 kg ha**-1, winter triticale captured 47 to 82 kg N ha**-1 beyond that supplied as fertilizer.