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Oxidation Status and Gas Composition of Wet Turfgrass Thatch and Soil 1
Author(s) -
Thompson D. C.,
Smiley R. W.,
Fowler M. Craven
Publication year - 1983
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1983.00021962007500040008x
Subject(s) - loam , chemistry , soil water , agronomy , environmental chemistry , arsenate , environmental science , arsenic , soil science , biology , organic chemistry
Excess thatch in turfgrasses is often associated with decreased plant vigor and increased disease susceptibility. Thatch is the primary rooting medium for many grasses, and is a substrate that possesses many prerequisites for anaerobiosis. The oxidation status and the gas composition in unsaturated thatch of mature Kentucky bluegrass ( Poa pratensis L.) were measured to determine if anaerobiosis occurs under field and greenhouse conditions. Soils under the sods included a Hudson silty clay loam (fine, illitic, mesic Glossaquic Hapludolf), a Riverhead sandy loam (coarse−loamy, mixed, mesic Typic Dystrochrept), and an Arkport fine sandy loam (coarse−loamy, mixed, mesic Psammentic Hapludalf). Measurements of redox potentials (E h ) and concentrations of oxygen (O 2 ), carbon dioxide (CO 2 ) and ethylene (C 2 H 4 ) were made. Conditions of poor oxidation, including low E h and O 2 and CO 2 concentrations, and accumulations of C 2 H 4 , were measured in thatch on poorly drained soils in the field and in the greenhouse. Applications of lime and calcium arsenate amplified the extent of poor oxidation in thatch, whereas calcium nitrate improved the oxidation status. Thatch depth and a coring procedure did not influence thatch oxidation. The E h varied diurnally and was lowest in wet thatches during warm, sunny days when thatch became warmer (by up to 7°C) than the air. Poorly oxidized conditions for periods over 7 h were measured in moist but unsaturated thatch in the field. The temperature of thatch appeared to be important in governing the oxidation status. Measurements of E h were considered to provide rapid and useful insights into the gaseous composition of wet thatches. Our results imply that phytotoxic products of poorly oxidized environments may accumulate in wet thatch on warm sunny days. Such conditions may also be common in field−grown cores of mature turfgrass which are moved to the greenhouse for study. The relevance of these results to the occurrence of diseases such as Fusarium blight are discussed.