The physical properties of container-growing substrates, particularly air space, container capacity, and bulk density, have a significant impact on plant growth, and knowledge of these properties is essential in properly managing nursery
Eugene K. Blythe and Donald J. Merhaut
Michael R. Evans and Mary M. Gachukia
phytotoxic levels of one more mineral nutrients. Other materials evaluated as potential alternatives to perlite are either too expensive or have unacceptably high bulk densities (e.g., calcined clay aggregates, gravel), which resulted in unacceptably high
Philip J. Brown, Lambert B. McCarty, Virgil L. Quisenberry, L. Ray Hubbard Jr. and M. Brad Addy
with native soil and vice versa, pore spaces in both soil sources can become compromised. Macropores in sand can be filled by finer soil particles, reducing porosity, increasing bulk density, and reducing necessary water movement through the profile
Johann S. Buck and Michael R. Evans
million tons of fresh rice hulls were produced annually in the United States. According to Bunt (1988) and Hanan (1998) , fresh rice hulls had a bulk density of 0.10 g·cm −3 , water-holding capacity of 20% (v/v), total pore space of 89% (v/v), and an
Rachel E. Rudolph, Lisa W. DeVetter, Inga A. Zasada and Cedar Hesse
physical and chemical measurements. Soil bulk density ( D b ) measurements were collected in treatment plot alleyways in Spring and Fall of 2015 and 2016. Two D b measurements were collected in the alleyways on either side of the raised bed for a total of
D.M. Glenn, J. Kotcon and W.V. Welker
Three soil management treatments (cultivation, herbicide, and killed sod) were established in the drive middle of a 10-year-old apple orchard removed the year prior to planting peaches. The cultivation and herbicide treatments used preplant tillage, leaving a bare soil surface, whereas the killed-sod system was untilled. Peach trees (Prunus persica L. Batsch) were planted, and growth, yield, and soil bulk density were measured after 3 years. There were no differences in tree growth or yield for the three treatments These results were contrary to published reports that the killed-sod system increased early tree growth. The lack of growth response in the killed-sod system was attributed to the high soil bulk density remaining from the previous orchard. We concluded that truck and tractor traffic in the drive middle causes severe soil compaction, which may limit root development. The soil compaction can only be moderated by tillage.
Carl E. Niedziela Jr. and Paul V. Nelson
A new tube method for determining physical properties in container substrates was compared to an existing system. While both offer the advantages of undisturbed substrate and measurement of properties without altering the geometry of the substrate in the container, the tube method is easier to conduct. Both methods proved equally effective for determining air-tilled porosity, container capacity, total porosity, bulk density, and particle density.
Linda L. Taylor, Alexander X. Niemiera, Robert D. Wright and J. Roger Harris
lamps from 0600 hr to 2000 hr daily. Cation exchange capacity, carbon-to-nitrogen ratio, particle size distribution, and bulk density. Cation exchange capacity, C:N ratio, particle size distribution, and BD were determined for five treatments: non
Jordan M. Craft, Christian M. Baldwin, Wayne H. Philley, James D. McCurdy, Barry R. Stewart, Maria Tomaso-Peterson and Eugene K. Blythe
). Hollow-tine aerification is also used to reduce compaction, which is quantified by measuring bulk density and surface firmness. Increasing the number of HT aerification events has been reported to improve bulk density ( Atkinson et al., 2012 ; Murphy et
B.H. Ownley, D.M. Benson and T. E. Bilderback
One-year-old Rhododendron L. `Nova Zembla' were grown in four container media infested with Phytophthora cinnamomi Rands. The media (all v/v) were pine bark, 3 pine bark:1 sand, 3 pine bark:1 peat, and 1 peat: 1 sand: 1 soil. After 20 weeks, plants were evaluated for root rot symptoms and the total porosity, air space, moisture-holding capacity, and bulk density were determined for all media. All media provided adequate moisture-holding capacity for container production of rhododendron in noninfested media. Shoot fresh weight in noninfested media was positively correlated with bulk density and water (percent by volume) held in the 1.0- to 5.0-kPa matric tension range and negatively correlated with total porosity and air space. Root rot severity was greatest in peat: sand: soil, intermediate in pine bark: peat, and least in pine bark and pine bark: sand. Root rot severity was negatively correlated with total porosity and air space and positively correlated with bulk density and water (percent by volume) held in the 5.0- to 10.0-kPa matric tension range.