@article{bigelow_bowman_cassel_2004, title={Physical properties of three sand size classes amended with inorganic materials or sphagnum peat moss for putting green rootzones}, volume={44}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci2004.0900}, abstractNote={Modern putting green rootzones are typically constructed using sands to avoid compaction and facilitate rapid drainage. Sands are often amended with organic matter (OM) such as sphagnum peat moss (SP) to increase moisture holding capacity. However, OM decomposition into finely divided material may negatively affect long-term soil physical properties. Inorganic amendments (IAs) having high water retention may be more suitable because of their resistance to biodegradation. A laboratory study determined the physical properties [bulk density, saturated hydraulic conductivity (Ksat), water retention, and pore size distribution] of three USDA sand size classes (fine, medium, and coarse) with and without amendment. Amendments used were calcined clay, vitrified clay, extruded diatomaceous earth, a processed zeolite, and SP. Amendments were tested at two incorporation rates (10 and 20% v/v), and in situ in 30-cm-deep rootzones at two incorporation depths (15 and 30 cm). Bulk density decreased, total porosity increased, and Ksat declined with amendment rate, but varied considerably depending on amendment, sand size, and incorporation depth. The Ksat was high for all mixtures, averaging 250 cm h−1, probably because of the very uniform sands. On the basis of standard pressure plate methods, IAs increased total water holding capacity (WHC) of all three sands but did not increase available water. However, a unique bioassay for available water indicated that porous IAs may contain appreciably more available water than measured by the pressure plate technique. Although the IAs significantly altered the physical properties of the three sands, they were not as effective as SP at improving water retention in coarse-textured, drought-prone sands.}, number={3}, journal={CROP SCIENCE}, author={Bigelow, CA and Bowman, DC and Cassel, DK}, year={2004}, pages={900–907} }
 @article{bigelow_bowman_wollum_2002, title={Characterization of soil microbial population dynamics in newly constructed sand-based rootzones}, volume={42}, DOI={10.2135/cropsci2002.1611}, abstractNote={Modern sand-based golf course putting greens are constructed for optimum soil physical properties. However, since they are sand based and synthetically prepared, it is often perceived that they support a less numerous and diverse microbial population than comparable native soils. This field study was conducted to monitor the microbial properties of five newly constructed sand-based rootzone mixtures planted to creeping bentgrass (Agrostis stolonifera var. palustris Huds. Farw.) during the first 2 yr of turfgrass establishment. Bacteria, fungi, actinomycetes, and aerobic spore forming (Bacillus spp.) populations were determined on selective media. Nitrifiers and denitrifiers were estimated by a most probable number (MPN) technique. Within the first 6 mo after seeding, bacteria exceeded 10 8 cfu g -1 dry soil, similar to levels recorded in a mature sand-based putting green. Bacteria were most numerous followed by actinomycetes, fungi, and Bacillus spp., respectively. Temporal changes in microbial populations were observed only in year one. The nitrogen transforming populations were numerically smaller (<10 4 cfu g -1 dry soil) than total bacteria but followed a similar temporal trend. Rootzone amendments had minimal effects on microbial properties but environmental factors and an actively growing turfgrass root system may have a greater influence on microbial activity.}, number={5}, journal={Crop Science}, author={Bigelow, C. A. and Bowman, D. C. and Wollum, A. G.}, year={2002}, pages={1611–1614} }
 @article{bigelow_bowman_cassel_rufty_2001, title={Creeping bentgrass response to inorganic soil amendments and mechanically induced subsurface drainage and aeration}, volume={41}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci2001.413797x}, abstractNote={Creeping bentgrass (Agrostis stolonifera var. palustris Huds. Farw.) golf greens often decline under the hot, humid summer conditions of the southeastern USA. Factors associated with this decline may be poor soil aeration, excessive soil wetness, high temperatures, and turfgrass diseases. A field study evaluated a mechanical forced air system for its ability to modify the soil water content and oxygen (O2) status of newly constructed sand‐based rootzones, and its effects on turfgrass quality (TQ) and seasonal bentgrass rooting. Three drainage situations were studied: gravity drainage (control treatment) and gravity drainage supplemented by two mechanically induced drainage treatments, water evacuation (WE) or WE followed by air‐injection (AI). In addition, the effects of peat moss and several inorganic soil amendments on bentgrass establishment and growth were studied. Compared with gravity drainage, WE significantly decreased water contents (0.01–0.05 m3 m−3) averaged across the 0‐ to 27‐cm depth, with the greatest change occurring near the bottom of the rooting media. Seasonal fluctuations in soil O2 and CO2 concentrations were observed, but O2 remained high, 0.19 m3 m−3, and CO2 was low, <0.01 m3 m−3, regardless of drainage treatment. Drainage treatments had no effect on TQ or root mass density (RMD). However, both TQ and RMD increased from 1998 to 1999, possibly becaue of greater turfgrass density. Amendments had significant effects on establishment and TQ in the following order: peat moss > Ecolite = Profile > Greenschoice ≥ unamended sand. This response was probably due to improved water and nutrient retention of the amended rootzones. Although the forced air–vacuum technology provided little benefit in these newly constructed greens, it may be useful on mature putting greens that suffer from poor soil aeration or drainage.}, number={3}, journal={CROP SCIENCE}, author={Bigelow, CA and Bowman, DC and Cassel, DK and Rufty, TW}, year={2001}, pages={797–805} }
 @article{bigelow_bowman_cassel_2001, title={Nitrogen leaching in sand-based rootzones amended with inorganic soil amendments and sphagnum peat}, volume={126}, number={1}, journal={Journal of the American Society for Horticultural Science}, author={Bigelow, C. A. and Bowman, D. C. and Cassel, D. K.}, year={2001}, pages={151–156} }
 @article{bruneau_bigelow_cooper_bowman_2001, title={Performance of creeping bentgrass cultivars maintained at two mowing heights and under two fungicide regimes in North Carolina}, volume={9}, journal={International Turfgrass Society Research Journal}, author={Bruneau, A. H. and Bigelow, C. A. and Cooper, R. J. and Bowman, D. C.}, year={2001}, pages={835} }
 @article{bigelow_bowman_cassel_2001, title={Water retention of sand-based putting green mixtures as affected by the presence of gravel sub-layers}, volume={9}, journal={International Turfgrass Society Research Journal}, author={Bigelow, C. A. and Bowman, D. C. and Cassel, D. K.}, year={2001}, pages={479} }
 @article{bigelow_cassel_bowman_1999, title={Soil amendments: reduce nitrate leaching}, volume={8}, number={9}, journal={Turf Grass Trends}, author={Bigelow, C. A. and Cassel, D. K. and Bowman, D. C.}, year={1999}, pages={11} }