Efficacy of Foliar Applied Liquid Fertilizer Affected by Tank-Mixed Organic Amendment on Creeping Bentgrass.

Foliar application of fertilizer on turfgrass via overhead fertigation or spray can increase the absorption efficiency and uniformity.  It can also be combined with other chemical applications to save labor and energy.  However, foliar application of N may result in root growth reduction, and under certain circumstances, leaf burning.  The objective of this study was to evaluate if liquid organic amendment can be tank mixed with liquid fertilizer to improve fertilization use efficacy.  This greenhouse study was conducted on creeping bentgrass grown in sand and sand/peat (90:10, v/v) root zones maintained at fairway height.  Four fertilizer packages, Contec DG^TM 33-0-0 and Minors package 0-1-1, Cytozorb-S (4-0-1), Nusion (29-2-3), and Jack’s all purpose 20-20-20 with or without Rev^TM, a liquid suspension derived from naturally mined humic materials, were included in the study along with a granular application of Milorganite.  The foliar fertilization was applied every two weeks and Milorganite every four weeks.  Tank mixing Rev^TM with fertilizer reduced the surging of above ground growth after the application, and resulted in better or same turfgrass visual quality compared to foliar fertilization only.  The benefit of tank mixing the organic amendment with fertilizer also was shown from the increased root/shoot ratio and sustaining of visual quality during drought stress, especially for grasses in sand-based root zones.