Bermudagrass Management in the Southern Piedmont USA. II. Soil Phosphorus

ABSTRACT which can become exposed at the soil surface from a long history of erosion (Bruce et al., 1990).Plant production can be limited by low levels of available P due Poultry production in the Appalachian Piedmont is ex-to high P-fixation capacity in soils of the southeastern USA. On the tensive (U.S. Dep. of Commerce, 1992). Manure mixedother hand, there is increasing concern about excessive application with bedding material (i.e., litter) at the end of the pro-of P to soil, especially when manure application is based upon N duction cycle is cleared from confinement housing andcontent. We evaluated changes in Mehlich-I extractable soil P during 5 yr of bermudagrass [Cynodon dactylon (L.) Pers.] management applied to nearby land as a source of valuable nutrients varying in fertilization [inorganic and broiler chicken (Gallus gallus) for crop and pasture production. Depending upon man-litter] and harvest strategy (unharvested, low and high cattle (Bos agement, however, repeated application of poultry litter taurus) grazing pressure, and haying). Broiler litter supplied eight to the same land could become a source of excessive times more P than inorganic fertilization to meet the N requirement. nutrients that would threaten water quality (Sharpley At a depth of 0 to 6 cm, Mehlich-I extractable soil P increased 0.8 et al., 1993; Kingery et al., 1994). Environmental regula-1.6 mg kg1 yr1 (4 8 % of total P added) with inorganic-only fer