Perennial Ryegrass Wear Resistance and Soil Amendment by Ca- and Mg-Silicates

Abstract

Proactive optimization of soil chemistry is a task commonly overlooked by agronomic practitioners. Agricultural field assessments have reported depletion of extractable soil silicon (Si) from shallow depths of intensively managed systems. While not recognized as a plant-essential nutrient, Si accumulates in epidermal and vascular tissue of grass leaves, sheaths, and shoots. A field study of Ca/Mg-silicate (SiO3) pelletized soil conditioner was initiated on a perennial ryegrass (Lolium perenne L. cvs. 1:1:1 Manhattan, Brightstar SLT, Mach 1) athletic field in 2010. Plots were trafficked by a wear simulator weekly, June through Sept. in 2011 and 2012. Canopy quality measures, clipping yield, tissue composition, soil pH, and plant-available soil Si levels were regularly collected over the two-year study. Under intense wear treatment (traffic), perennial ryegrass plots treated annually by granular application of 1220 or 2440 kg Ca/Mg-silicates per hectare showed significantly improved mean canopy density relative to plots receiving equal Ca and Mg as lime. These described Ca/Mg-SiO3 annual application rates coincided with acetic acid extractable soil Si levels > 70 mg kg−1 in the 0- to 8-cm soil depth. Experimental and temporal variability preclude reporting of a critical threshold concentration of leaf Si for improved perennial ryegrass wear tolerance. Future efforts towards this end should sample tissue of plots receiving wear treatment, rather than adjacent, non-worn proxies.

Creeping Bentgrass Fairway Wear Resistance by Granular Topdressing of Ca/Mg-rich Liming Agents

“…The methods described here are highly similar to those used in a previously published study [13], but are detailed again to support comprehensive interpretation of the present experiment. A two-year field trial evaluating commercial granular liming agents commenced November 2010 on a one-year old creeping bentgrass (Agrostis stolonifera L. cv.…”

“…Soil cores were divided into 0 to 5, 5 to 10, and 10 to 15 cm depth segments, dried in a forced-air oven (70 °C) for 72 h, and ground to pass a 1-mm sieve. These depth segments were sieved prior to splitting for 1:1 soil pH measures or 0.5 M acetic acid soil extraction of plant-available Si [9,13,33]. Clipping yields were collected over a single, lengthwise pass across non-worn sub-plots in June, July, and September 2011; and June and August 2012.…”

“…Once its contents were thoroughly dry, each bag was re-weighed, then recombined with its original paper bag contents before weighing to 0.1-mg resolution. These dried clipping yields were split for Si-extraction [34] or acid digestion for plant essential nutrient concentration analysis by PSU-AASL [13].…”

“…), perennial ryegrass (Lolium perenne L.), bermudagrass (Cynodon dactylon L.), and zoysiagrass (Zoysia japonica Steud.) have resulted in statistically significant increases in Si accumulation within leaf tissue [11][12][13][14][15]; whereas, Si fertilizer applications to seashore paspalum (Paspalum vaginatum L.) resulted in significant increases of leaf Si during one of two field evaluations [16]. Similarly, spray application of liquid Si fertilizers to creeping bentgrass resulted in significant leaf concentration increase in one of the two recent field studies conducted in the Southern United States [17,18].…”

“…With a calcium carbonate equivalency ranging from 50 to 85%, calcium silicate has long served as an eligible, regionally cost-effective ingredient of cement and agricultural limestone products [19,20]. While neutralization of exchangeable acidity by traditional carbonate and hydr/oxide agents generate CO 2 and/or H 2 O [20], the same by Ca/MgSiO 3 produces silicic acid, H 4 SiO 4 [13]. This silicate form is sparingly soluble, but dependably absorbed by roots and distributed to cuticular, vascular, and epidermal tissues [3,4,21].…”