|Loecke, T - DEPT OF AGRON, ISU|
|Liebman, M - DEPT OF AGRON, ISU|
|Richard, T - DEPT AG&BIOSYS ENG, ISU|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 30, 2004
Publication Date: January 30, 2004
Citation: Loecke, T.D., Liebman, M., Cambardella, C.A., Richard, T.L. 2004. Growth responses of corn (Zea mays L.) to composted and fresh solid swine (Sus scrofa L.) manure. Crop Science. 44:177-184. Interpretive Summary: Swine production in deep-bedded hoop structures is a relatively new swine finishing system in the upper Midwest. One advantage of this type of system is that the manure/bedding material can be easily removed for composting prior to field application. Composted manures may provide plant growth benefits other than nutrients compared to fresh manures. This field study evaluated the impact of swine hoop manure form (composted or fresh) and timing of application (spring or fall application) on corn growth parameters for a site in central Iowa in 2000 and 2001. In both 2000 and 2001, corn in the composted manure treatment was significantly larger than corn in the fresh manure treatment, although grain yield was only greater in 2001. Compared to the fresh manure treatment, composted manure increased corn crop growth rate, leaf N concentration, and leaf area index. The results emphasize the potential impact of plant-growth stimulating and/or phytotoxic substances on corn growth responses to the animal manures used in this study. The information will be useful to scientists interested in evaluating corn growth response to animal manures in corn-soybean production systems.
Technical Abstract: Swine (Sus scrofa L.) production in deep-bedded hoop structures is a relatively new swine finishing system in which manure can be applied fresh or composted prior to field application. We conducted field-plot trials near Boone, IA, during two growing seasons to determine the effects of fresh and composted swine hoop manure on corn (Zea mays L.) growth responses. Both amendments were applied at a total N rate of 336 kg N ha-1 in the spring before planting corn, and a functional growth analysis approach using frequent plant harvests was used to assess total aerial dry matter production and leaf area development of the crop. In 2000, fresh manure had phytotoxic effects on corn seedlings in the field and on annual ryegrass (Lolium multiflorum L.) seedlings in the laboratory. In both 2000 and 2001, corn in the composted manure treatment was significantly larger than did corn in the fresh manure treatment. Corn grain yield was greater in the composted manure treatment in 2001. In 2000, size differences were evident early in the season, whereas in 2001, size differences became evident near flowering. The time of treatment separation in both years coincided with the driest soil conditions of the season. As compared to the fresh manure treatment, composted manure increased corn crop growth rate, leaf N concentration, leaf area index, and, in one of two years, net assimilation rate. Plant growth stimulating substances and/or phytotoxic substances may have been important factors affecting corn growth responses to the composted and fresh swine hoop manure and merit additional research.