The Effects Of Reinforcement Inclusions On Wear Tolerance, Playing Quality And Physical Properties In A Silt Loam And Sand Rootzone Matrix

Reinforcement inclusions have been advocated to alleviate wear, compaction, and unstable surfaces in sports fields, but little research on the effects of these materials has been conducted in the USA. Experiments were established on a native silt loam and a sand rootzone matrix, seeded with a Kentucky bluegrass (Poa pratensis L.) blend, at the Joseph Troll Turf Research Center, University of Massachusetts, Amherst, USA to determine the effects of reinforcement inclusions on wear, surface hardness, traction, ball roll, ball bounce resilience, water infiltration rate, soil bulk density, air porosity, total porosity, and root weights. Three types of reinforcement inclusions (Sportgrass, Netlon, Turfgrids) were tested along with a non-reinforced control in a three year study. The treatments were set out in a randomized complete block design with four replications in both soils. No inclusion provided less wear or greater infiltration or air-filled porosity relative to the control. Reinforcement inclusions showed significant differences, however, in surface hardness, traction, and ball roll relative to the control, although this varied with the time of year. Infiltration rates, airfilled porosity, total pore space, bulk density, hardness, traction, ball roll, and ball rebound were greater on the sand rootzone than on the silt loam. Significant correlations were present between soil bulk density, surface hardness, traction, and ball roll. Based on our study, the use of reinforcement inclusions to provide better wear tolerance for sand or native soil athletic fields is not warranted. Certain playing surface characteristics, however, may be slightly improved with the use of reinforcement inclusions. The use of sands for sports surfaces is justified based upon the improvement in playing quality characteristics and soil physical properties important to a good playing surface.

Bentgrass response to K fertilization and K release rates from eight sand rootzone sources used in putting green construction.

There is a lack of plant response to fertilizer K in some sandy soils even though routine soil tests for soil available K are shown to be low. This lack of plant response to K fertilizer application may be explained by K release from nonexchangeable forms. Greenhouse and laboratory experiments were conducted to evaluate (a) response of bentgrass (Agrostis palustris [Agrostis stolonifera var. palustris]) cv. Pencross grown in rootzones with different sand sources to K fertilizer application and (b) K release from nonexchangeable forms from the different sand sources as an index to K availability. Experimental variables in the greenhouse were 2 K levels (0 and 250 mg K/kg soil) and 8 sand rootzone sources. Rootzone soils were sub-irrigated to ensure no K loss from leaching. Two laboratory methods (boiling 1 M HNO3 extraction and continuous leaching with 0.01 M HCl) and total K uptake by the bentgrass were employed to index K release from nonexchangeable forms for each rootzone source. K fertilizer application significantly increased bentgrass yield growing in one rootzone source and root weight in 3 rootzone sources. K uptake by bentgrass and the 2 laboratory methods showed important differences in K release from the sand rootzones. The K removed by the 2 laboratory methods was closely related to leaf tissue K and K uptake, with the 1 M HNO3 extraction method providing the closest fit. The release of K from primary minerals in some rootzones with high sand content is proceeding at rates to satisfy bentgrass requirements for K. The 1 M HNO3 extraction method may provide an alternative to the routine laboratory procedures presently being used to measure the extractable K in sand-based constructed putting greens by measuring K contributed by nonexchangeable forms.

Das Zunz'sche Buch über die "gottesdienstlichen Vorträge" und der heutige Sand der Midraschforschung

Julius Theodor

Tel-Awiw: The Soap Bubble City : Die Stadt auf Sand gebaut

Jessie Ethel Sampter

Der Sand am Ufer des Meeres : (Gedicht)

Baruch Placzek

Ein Ausflug in die Sand- und Sumpfflora von Walldorf und Waghäusel

Von A. Kneucker

Max Sand, Brustbild

Signatur des Originals: S 36/F01714

Julius Benseler als Tanzmeister, Rollenbild, in: Bedřich Smetana: Die verkaufte Braut

Signatur des Originals: S 36/F02991

Julius Benseler als Tanzmeister, Rollenbild, in: Bedřich Smetana: Die verkaufte Braut

Signatur des Originals: S 36/F02993

George Sand, Brustbild

Signatur des Originals: S 36/F06113

Maria Müller, {[N.N.], Rollenbild, Doppelbildnis, in: Bedřich Smetana: Prodaná nevešta (Die verkaufte Braut)

Signatur des Originals: S 36/F10993

Maria Müller, {[N.N.], Rollenbild, Doppelbildnis, in: Bedřich Smetana: Prodaná nevešta (Die verkaufte Braut)

Signatur des Originals: S 36/F10996

Maria Müller, {[N.N.], Rollenbild, Kniestück, Doppelbildnis, in: Bedřich Smetana: Prodaná nevešta (Die verkaufte Braut)

Signatur des Originals: S 36/F10997

Oskar Wittazscheck als Wenzel, Rollenbild, Brustbild, in: Bedřich Smetana: Prodaná nevěsta (Die verkaufte Braut)

Signatur des Originals: S 36/F11293

Maria Müller als Mařenka, Rollenbild, Kniestück, Profil, in: Bedřich Smetana: Prodaná nevešta (Die verkaufte Braut)

Signatur des Originals: S 36/F11667