Cotton root response to free-air CO[sub 2] enrichment

Miscellaneous · Fri Jan 01 00:00:00 EST 1993

OSTI ID:5437896

Prior, S A

Field studies were undertaken for two years to investigate the effect of CO[sub 2] concentration (360 and 550 [mu]mol mol[sup [minus]1]) and soil water regime [wet, 100% of evapotranspiration (ET) replaced and dry, 75% (1990) and 76% (1991) of ET replaced] on cotton root growth at two growth stages (vegetative and reproductive). A new exposure method called free-air CO[sub 2] enrichment (FACE) was used to create large-scale test atmospheres in the field with minimal disturbance of plant microclimate. Soil root cores to a depth of 90 cm were collected within the crop row and interrow to evaluate vertical and horizontal rooting distribution. Root systems were excavated to describe morphological patterns. Laterals were divided into four classes based on diameter size . The effect of water stress of its interaction with CO[sub 2] were generally nonexistent with respect to root density. At the second sampling (reproductive), root weight per unit length was usually greater under water stress. At the initial sampling (vegetative), whole profile root density and root weight per unit length were usually increased under high CO[sub 2]. The positive effects of CO[sub 2] were limited to the 0.5 m position. At the first sampling, root dry weight density by depth increment were usually higher under FACE throughout the profile and at all horizontal positions, whereas increase in root length density were restricted to interrow positions. For most positions at the second sampling, enhancements in root weight per unit length and root length density occurred in the upper parts of the soil profile. At this period, FACE increased root dry weight density throughout the profile, especially at the interrow positions. Water stress had no effect on the taproot system at the initial period, but water stress at the second period resulted in reduced length, volume, and dry weight in the second year. At both samplings, most of the taproot measurements were increased due to extra CO[sub 2].

• Research Organization: Auburn Univ., AL (United States)
• OSTI ID: 5437896
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
CARBON DIOXIDE
BIOLOGICAL EFFECTS
ECOLOGICAL CONCENTRATION
COTTON PLANTS
ROOTS
PLANT GROWTH
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
GROWTH
MAGNOLIOPHYTA
MAGNOLIOPSIDA
OXIDES
OXYGEN COMPOUNDS
PLANTS
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