PAPER SLUDGE AMENDMENTS FOR TURFGRASS

The behavior of turfgrass grown on paper-sludge-amended soils was eval uated over 2 years. Two experiments were performed, one with deinked s ludge and another with primary sludge. Four paper sludge, sand, and or ganic soil substrate mixtures with proportions ranging from 0% to 50% paper sludge were incorporated into existing soils. Two fertilization levels were applied in strip plots across sludge treatments and three turfgrasses of seeded Kentucky bluegrass (Pea pratensis L. 'Georgetown '), Kentucky bluegrass sod, and an 80 Kentucky bluegrass : 20 perennia l ryegrass (Lolium perenne L. 'Prelude') seed mix were arranged within split plots. Effects of deinked and primary sludge experiments were s imilar. Supplemental N and, to a lesser degree, P and K fertilization with N at approximate to 4.5 to 5.5 t . ha(-1), P at 1.18 to 1.26 t . ha(-1), and K at 1.31 to 1.46 t . ha(-1) improved ground cover, turf c olor, and stand quality. Despite differences in visual evaluations, le af mineral nutrition was only slightly affected by fertilization treat ments. Soil in nonfertilized plots was several times lower in N-NO3 wh en compared to fertilized plots, regardless of sludge rate. Soil in fe rtilized plots had higher concentrations of inorganic N regardless of sludge amendment. The soil C:N ratio was approximate to 13:1 in noname nded plots and more than 15:1 under the highest sludge rate. Deinked a nd primary paper sludges can be used effectively as soil amendments if turfgrass receives adequate supplemental N, P, and K.