TY - JOUR T1 - Trends in phosphorus fertility of New York agricultural land JF - Journal of Soil and Water Conservation SP - 10 LP - 20 VL - 60 IS - 1 AU - Q.M. Ketterings AU - J.E. Kahabka AU - W.S. Reid Y1 - 2005/01/01 UR - http://www.jswconline.org/content/60/1/10.abstract N2 - Monitoring of soil test phosphorus (STP) levels over time is essential for the evaluation of fertility management practices. Our objectives were to (1) assess the current soil P fertility status of New York at state, regional, county, and farm level, (2) determine statewide and regional trends over the past 40 years, and (3) investigate the impact of soil test phosphorus trends on fertilizer needs for typical corn-alfalfa/grass rotations. A 1995 to 2001 dataset (119,326 soil samples analyzed for Morgan extractable P) from the Cornell Nutrient Analysis Laboratory was analyzed and compared with published data from 1957-58, 1977-78, 1981, and 1982, and unpublished data from 1985 to 95. Mean statewide P levels remained constant from 1957 to 1980 (26 to 29 percent high or very high in P), but steadily increased after 1980. Currently, 47 percent of the soil samples test equal to or higher than the critical agronomic soil test phosphorus for field crops (4.5 mg kg−1 or 9 lbs ac−1 Morgan extractable P). The highest soil test levels occur in vegetable production regions on Long Island and the highly productive dairy, vegetable and fruit areas in Western New York while the greatest increases over time took place in the dairy-dominated northern and northeastern regions. As these soils reach progressively higher P levels, fertilizer P needs for New York will diminish but more attentive management is needed to ensure that environmental thresholds are not exceeded. ER -