Monday, November 13, 2006

Response of Forage Chicory Seedlings to Available Soil Phosphorus.

Kimberly Cassida1, Joyce Foster1, Matt Sanderson2, Javier Gonzalez3, and K. D. Ritchey4. (1) 1224 Airport Road, USDA-ARS, USDA-ARS, Appalacien Farming System Research Center, Beaver, WV 25813-9423, (2) "Bldg 3702, Curtin Rd, USDA-ARS", Pasture Research Lab, Pasture Research Lab, University Park, PA 16802-3702, United States of America, (3) USDA-ARS-AFSRC, USDA-ARS-AFSRC, 1224 Airport Road, Beaver, WV 25813, (4) USDA, ARS, Appalachian Farming Systems Research Center, 1224 Airport Rd., Beaver, WV 25813

<> <>Phosphorus fertility may be responsible for observed differences in chemical composition of forage chicory (Cichorium intybus L.) on West Virginia and Pennsylvania soils, but P effects on chicory growth on these soils are unclear.  We evaluated the effect of available soil P (ASP) on ‘Puna’, ‘Lacerta’, and ‘Forage Feast’ chicory grown in a greenhouse using silt loam soils from WV and PA.  Soil pH and K were similar in the two soils.  The amount of triple superphosphate to add to each soil was determined using an adsorption isotherm approach and mixed with soils at rates equivalent to 28, 53, 72, and 112 kg ASP ha-1.  Plants were harvested at 48 and again at 77 days after planting.  At a given ASP, shoots were always heavier, had more leaves per plant, and had greater leaf area in the PA soil than in the WV soil. Growth response per unit ASP was greater in the first than the second harvest.  Shoot mass, leaves per plant, and leaf area increased with ASP in both soils in the first harvest, but not always at similar rates.  Seedling regrowth  responded to ASP only in the WV soil, with evidence of diminishing response at higher ASP.  Few cultivar differences were detected.  Results suggest ASP is not the only factor that affects seedling productivity on these two soils.