Factors Affecting Foliar Nitrogen Uptake by Creeping Bentgrass

Turfgrass managers frequently apply N as a foliar spray when low application rates are desired. This practice is believed to promote foliar N uptake that benefits turf; however, very little information is available concerning the quantity of N absorbed by turfgrass foliage or the effect of various spray parameters on foliar N uptake under field conditions. This research was conducted to evaluate fertilizer N uptake efficiency of foliarly applied N-15 to creeping bentgrass [Agrostis stolonifera var. L. palustris (Huds.) Farw. 'Pennlinks'] under field conditions. The effects of spray volume, N carrier, adjuvant addition, and tank mixing with commonly applied turf care products (e.g. chlorothalonil) on foliar N uptake were conducted to evaluate foliar uptake of fertilizer N-15 by creeping bentgrass. From 6 to 34% of foliar-applied N was taken up mostly within 2 h and completely by 4 to 6 h after fertilizer application. Uptake efficiency increased significantly when spray volume was decreased but was unaffected by N carrier, adjuvant addition, or tank mixing.