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

Derek T Pruyne,Maxim J Schlossberg,Wakar Uddin

doi:10.3390/agronomy9100578

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.

Highlights

After oxygen, silicon (Si) is the most abundant element in the Earth’s crust and a dependable constituent of the soil mineral fraction [1]
Plots treated by 2440 kg showed significantly greater canopy density worn limestone-treated year)−1 showed significantly greater canopy density thanthan the limed counterparts on plots on two of the first six observation dates
Plots treated by 2440 kg−1 Ca/Mg-silicates showed significantly greater canopy density than the limed counterparts on only one sampling date in 2012 (Figure 6)

Summary

Introduction

Silicon (Si) is the most abundant element in the Earth’s crust and a dependable constituent of the soil mineral fraction [1]. Not recognized as a plant-essential nutrient, Si naturally accumulates in tissue of many plant species [2]. This plant uptake results in intra- and extracellular silica deposition in the epidermal and vascular tissue of monocotyledonous leaves and roots [3,4]. Uptake of Si by roots of broadleaf and grass plants support recommendations for silicon fertilization [8]. Silica uptake in rice has been shown to increase with SiO3 rate [9]

Methods

Results

Conclusion