DRY-MATTER PRODUCTION, ALLOCATION AND NUTRITIVE VALUE OF FORAGE CHICORY CULTIVARS AS A FUNCTION OF NITROGEN

Authors: Belesky, David; Ruckle, Joyce; Clapham, William

Submitted to: Journal of Agronomy and Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/5/2003
Publication Date: 4/3/2004
Citation: Belesky, D.P., Ruckle, J.M., Clapham, W.M. 2004. Dry-matter production, allocation and nutritive value of forage chicory cultivars as a function of nitrogen.. Journal of Agronomy and Crop Science, 190:100-110.

Interpretive Summary: Chicory is a valuable addition to the array of forage plant resources for use in pasture. Chicory also has a remarkable ability to respond to high nutrient conditions. Several cultivars of chicory are available to the forage-livestock producer but no clear understanding of how the cultivars respond to added nitrogen (N) form or amount exists, especially during the seedling and early development phase. Understanding how chicory responds to supplementary N during early phases of development will provide some insight into chicory establishment in existing pasture, and the nutrient demands required to maintain chicory in pasture. We conducted greenhouse experiments to evaluate the development and productivity of chicory to N inputs. One cultivar of chicory was highly productive without additional N other than the small amount present in the rooting medium, suggesting that it might be useful in pastures that do not receive supplemental N. Applying N increased the quantity and the duration of leafy chicory productivity in two cultivars developed for pasture use, showing that N input improves the seasonal distribution as well as total production of chicory.

Technical Abstract: Forage chicory responds to supplemental N fertilizer, with greater herbage mass and larger leaves occurring at greater amounts of N, which is important in terms of stand establishment and herbage production. We conducted experiments in a glasshouse to determine if a single application of N (0, 50 and 100 g N kg-1 soil) in either of two forms (NH4NO3 or urea) to soil with < 10 g N kg-1 soil, influenced the amount and allocation of dry matter, N and total non-structural carbohydrate (TNC) among roots and shoots in chicory cultivars with different morphology. Cultivars differed in response to N source and amount. Forage Feast produced the largest roots and greatest herbage mass without exogenous N. Leaf appearance rate in both Lacerta and Grasslands Puna increased as the amount of N applied was increased. Maximum dry matter production occurred later in the growth interval and obtained higher rates when N was applied. The instantaneous growth rates of Grasslands Puna and Lacerta in plants receiving 100 g N kg-1 soil were three times that of plants without supplemental N. Findings lead to N management practices for successful establishment and productive stands of forage chicory.