Effect of Nitrogen Fertilization on the Recovery of ‘Merion’ Kentucky Bluegrass from Scalping and Wilting1
- T. L. Watschke and
- D. V. Waddington2
This study was conducted on ‘Merion’ bluegrass (Poa pratensis L.) to determine the effect of different N sources, rates, and timing on the resistance to, and recovery from, wilting and scalping. In August 1972, sod plugs were taken from field plots fertilized at different rates and application dates with urea, Uramite (38-0-0, ureaform), Milorganite (6-1.3-0, activated sewage sludge), isobutylidene diurea (30-0-0; IBDU), Urex (29-0-0, extruded urea-paraffin matrix), and 18-6-12 (with twothirds of the N from ureaform), and a check plot. Plugs were placed in an unshaded greenhouse for several simultaneously conducted experiments.
One set of plugs was allowed to wilt. Turf fertilized at the highest N rate tended to wilt quickest, while the unfertilized check was most resistant to wilting. After watering, turf that was slowest to wilt, recovered quickest. Another set of plugs was allowed to grow 9 weeks, after which length, width, green and dry weight, and percent moisture of leaves were measured. The grass was scalped to 1.3 cm and data on regrowth were collected. Plants fertilized at the highest N rates recovered faster, had greater clipping weights, longer and wider leaves, and higher percent moisture than those lightly fertilized. Plants treated with a low rate of Uramite, however, recovered rapidly indicating release of residual N from prior seasons. Total nonstructural carbohydrates were lower for fertilized than unfertilized turf, and changes in carbohydrates with time were influenced by the N treatment. In general, as N rates increased, plants wilted quicker and recovered slower; recovery from scalping was improved; and carbohydrates decreased.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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