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James E. Altland and Charles R. Krause

. Particle size distributions were subjected to multivariate analysis of variance (ANOVA) to determine if distributions differed as a whole and then were analyzed by univariate ANOVA within each sieve size. Means were separated within a sieve size using

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Linda L. Taylor, Alexander X. Niemiera, Robert D. Wright, and J. Roger Harris

placed in plastic freezer bags and stored in a freezer at –15 °C for future CEC, C, N, BD, and particle size distribution analysis. For the remaining storage periods, ≈4 L of each of the 11 treatments was collected for the same analyses as at Day 1 and

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Jinsheng Huang, Paul R. Fisher, and William R. Argo

reaction, the particle size distribution of a liming material directly influences the dissolution rate and its effectiveness in neutralizing soil acidity. A particle size efficiency (PSE) factor can be assigned to each particle size fraction of an

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Juha Heiskanen

Two commercially produced growth media made of light, low humified sphagnum peat, were used to determine how filling into containers affects the particle size distribution and water retention characteristics of peat. It was shown that the filling procedure used broke up the peat particles, resulting in a significant increase in the proportion of particles < 1 mm (g·g-1). Due to the increased proportion of fine particles, the water retention of the peat media increased under wet conditions (-0.1 kPa matric potential), while the air-filled porosity decreased to nearly 0. Also, at matric potentials lower than -0.1 kPa, the reduction in air-filled porosity may restrict aeration and availability of oxygen to roots, thus reducing growth of plants.

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Manuel Abad, Fernando Fornes, Carolina Carrión, Vicente Noguera, Patricia Noguera, Ángel Maquieira, and Rosa Puchades

Selected physical properties of 13 coconut coir dusts from Asia, America, and Africa were compared to physical properties of sphagnum peat. All properties studied differed significantly between and within sources, and from the peat. Coir dusts from India, Sri Lanka, and Thailand were composed mainly of pithy tissue, whereas most of those from Costa Rica, Ivory Coast, and Mexico contained abundant fiber which was reflected by a higher coarseness index (percentage by weight of particles larger than 1 mm in diameter). Coir dust was evaluated as a lightweight material, and its total porosity was above 94% (by volume). It also exhibited a high air content (from 24% to 89% by volume) but a low easily available and total water-holding capacity which ranged from <1% to 36% by volume and from 137 to 786 mL·L–1, respectively. Physical properties of coir dust were strongly dependent on particle size distribution. Both easily available and total water-holding capacity declined proportionally with increasing coarseness index, while air content was positively correlated. Relative hydraulic conductivity in the range of 0 to 10 kPa suction dropped as particle size increased. Coir dusts with a particle size distribution similar to peat showed comparatively higher aeration and lower capacity to hold total and easily available water. An air–water balance similar to that in peat became apparent in coir dust at a comparatively lower coarseness index (29% vs. 63% by weight in peat). Stepwise multiple regression analysis showed that particles with diameters in the range of 0.125 to 1 mm had a remarkable and highly significant impact on the physical properties studied, while particles <0.125 mm and >1 mm had only a slight or nonsignificant effect.

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Ruying Wang, James W. Hempfling, Bruce B. Clarke, and James A. Murphy

air-filled porosity and saturated hydraulic conductivity compared with coarse or coarse-medium sand ( Murphy et al., 2001 ). Table 1. Particle size distribution of sands used for topdressing an annual bluegrass turf mowed at 2.8 mm in North Brunswick

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Magdalena Zazirska Gabriel, James E. Altland, and James S. Owen Jr

each substrate was prepared by mixing components with a shovel on a nonporous concrete floor. Substrates were stored individually in plastic containers in a dark, cool shed until needed for analysis. Table 1. Particle size distribution and physical

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Vickie Murphy, Kimberly Moore, M. Patrick Griffith, and Chad Husby

., Newton, MA). The stem was separated from the root system and dried separately. Leaflets, petioles, stems, and roots were dried separately at 63 °C for 7 d for dry weight determination. Substrate particle size distributions of substrates were measured

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Nikolaos Ntoulas, Panayiotis A. Nektarios, Thomais-Evelina Kapsali, Maria-Pinelopi Kaltsidi, Liebao Han, and Shuxia Yin

chemical characteristics determination Measurements included particle size distribution, pH, EC, moisture potential curves from 0 to 1000 mm suction of substrate mixtures, determination of the hydraulic conductivity of the final substrate mixes, and

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James E. Altland, James S. Owen Jr., Brian E. Jackson, and Jeb S. Fields

following procedures described in Fonteno and Harden (2010) . In addition, particle size distribution of 100 g oven-dried samples were determined for three replicates of each substrate by passing the substrate through seven sieves (6.30-, 2.00-, 0.71-, 0