applie d research By Beth Guertal, Ph.D., Professor, Crop, Soil and Environmental Sciences, Auburn University
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Nitrogen Fertilization Rates and Timings
for a Bermudagrass Home Lawn A recent (spring 2014) photograph from our N rate and N timing experiment. The square of white clover in the foreground is the plot that has received no nitrogen since 2010.
ypical nitrogen (N) fertilization recommendations for hybrid bermudagrass lawns in the southeastern United States are 3 to 6 lbs. of nitrogen per 1,000 ft2 per growing season, with the N rate varying with intensity of use and length of the growing season. However, there is limited information about best management of N rates and N timing for hybrid bermudagrass lawns. The objective of this project was to examine N rates (totals of 3, 4, 5 and 6 lbs. N per 1,000 ft2 per growing season) and N timing (all season, early spring, late fall) on the growth and performance of hybrid bermudagrass managed as a home lawn. We installed our study in 2010, and the experiment will continue through 2015.
The specific experiment — what we did The turfgrass for this study was a hybrid bermudagrass (likely ‘Tifway’), which was treated as a lower-input lawn, with a mowing height of 2". The study was a randomized complete block design of 19 N rate x timing treatments, with 4 replications of each treatment. The nitrogen (all granular urea, with that N watered in after application) was applied in April, May, June, July, August and September in each year as split applications to total 3, 4, 5 or 6 lbs. N 1,000 ft2. The nitrogen was applied in the following “programs”: • Equal — April, May, June, July, August and September (at 1/2, 2/3, 5/6 or 1 lb. N per 1,000 ft2 in each month) •S pring — April, May, June and July (at 3/4, 1, 1-1/4 or 1-1/2 lbs. N per 1,000 ft2 in each month) • Spring Short — April, May and June (at 1, 1-1/3, 1-2/3 or 2 lbs. N per 1,000 ft2 in each month) • Middle Months — May, June, July and August (at 3/4, 1, 1-1/4 or 1-1/2 lbs. per N 1,000 ft2 in each month) • Slow — All in May (6 lbs. N per 1,000 ft2 only in May) • None — Nothing