|Turner, Kenneth - Ken|
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/7/1999
Publication Date: N/A
Interpretive Summary: Forage chicory is a highly productive plant with good potential for use as a mid-summer component in pastures in the eastern US. Some experiments have shown that chicory growth increases as fertilizer nutrients like nitrogen are supplied in increasing amounts. This is important from the standpoint of herbage production, pasture longevity and forage quality for grazing livestock. We investigated chicory production and nutritive value as a function of nitrogen application. Applying high rates of nitrogen can boost chicory production but at the same time can accelerate chicory plant loss from the stand. We found that chicory did not persist at the higher rates of nitrogen application. Although less chicory was present in the stand, the loss was replaced by natural reseeding of other commonly occurring pasture plants like orchardgrass and white clover. Nutritive value data suggests that chicory alone may not contain enough energy for efficient use of the protein present in herbage by grazing livestock. We recommend that chicory be planted as part of a mixture to improve the quality of herbage available for grazing livestock. Our findings can be used by extension agents and farmers to develop planting recommendations of plant combinations to improve on-site nutrient use and nutritive value of forage available to grazing livestock.
Technical Abstract: Chicory (Cichorium intybus L.) is highly productive under mid-summer conditions in the eastern US. Defoliation and N rate affects chicory stand persistence. Active chicory growth in summer and responsiveness to N, could also lead to NO3-N accumulation. We conducted a field experiment for 3 yr on a Ramsey soil (fine-loamy, siliceous, mesic Typic Hapludult) in southern West Virginia. Dry matter (DM), botanical composition of swards, seasonal distribution of forage, in vitro organic matter disappearance (IVOMD), NO3-N and crude protein (CP) were determined as a function of annual spring N application. Each N rate was replicated three times in a randomized block design, with plots clipped at 6-wk intervals. Chicory dominated swards in the first year (1994) regardless of N rate, but by the third year (1996) ranged from about 40% (0N) to less than 5% (320N) of swards. Decline in chicory was compensated for by an increase in volunteer rgrasses and legumes and influenced DM response to N rate and overall herbage nutritive value. Dry matter production increased with N rate in 1994, but did not do so in 1996. More than 70% of total annual DM production in 1994 occurred after the first harvest, but by 1996 this was less than 50%, reflecting productivity patterns typical of cool-season swards. Nitrate concentrations in herbage were greatest (0.35 %) in 1995, a relatively dry year, and least (0.23%) in 1996 when the contribution of chicory to the sward was the least. Crude protein and IVOMD values suggest high forage quality throughout the course of the experiment. This work is part of a series of investigations concerning phenology of chicory, utility of chicory in full-season grazing regimes, and composition and in vitro digestion kinetics of chicory herbage.