Comparison of Bone Products for Phosphorus Availability

N (%) 8.60 2.60 4.65 P (%) 4.55 11.76 11.08 Summary. Three bone products (meat and bone meal, steamed bone meal, and bone chips) were compared to a water-soluble P source (monocalcium phosphate) for P availability and enhancement of tomato shoot growth. All bone products were finely ground to pass through a 40-mesh sieve. The products were added to a phosphorusdeficient greenhouse growing medium based on their P concentration with P at 50, 100, 200, and 400 mg•kg–1. Meat and bone meal produced the least shoot growth in 1992, but all products were similar in 1993. Growth peaked with P at 111 mg•kg–1 in 1992, but in 1993, P at 50 mg•kg–1 was sufficient. Shoot P uptake was in direct proportion to P availability in the soil mix, monocalcium phosphate having the highest shoot P content. Although bone products affected N,