Sterilization of Soil by Irradiation and Some Further Observations on Soil Enzyme Activity

Journal Article · Sun Jul 01 04:00:00 EDT 1962 · Soil Sci. Soc. Am. Proc.

DOI:https://doi.org/10.2136/sssaj1962.03615995002600040019x· OSTI ID:4712509

McLaren, A D; Luse, R A; Skujins, J J

In a study of radiosterilized soil as a medium for microbial and plant growth, survival curves for microorganisms were obtained with 5- and 9-Mev electrons, and hard x and gamma radiation. For a given soil, bacterial survival curves with these radiations were almost superimposable, but they differed among soils. Bacterial numbers in soils approached zero at 2-Mrep doses, but 4-Mrep doses were necessary to insure complete sterility for larger soil volumes. The number of surviving fungi approached zero with doses of about 0.5 Mrep with either of the irradiation treatments and in either Dublin or Yolo soil. The course of reinvasion of sterilized soil by chance contamination was followed after sterilization with a dose of 4 Mrep. Soil was exposed to air in the open and watered with a nutrient solution and then tap water. Bacterial numbers in the soil increased about 15-fold over the normal numbers in nonirradiated control soil after 21 days. There was no significant difference in growth of tomato or barley between irradiated and nonirradiated soil. Although phosphorus-deficient plants had stunted growth, well-fertilized plants had excellent growth; none showed any signs of toxicity. Macroscopic examination of plants grown in irradiated and nonirradiated soil showed no differences in root appearance. Soil sterilized by radiation still manifests enzyme activity (phosphatase, urease) in the presence of suitable substrates.

• Research Organization: Univ. of California, Berkeley
• Sponsoring Organization: USDOE
• NSA Number: NSA-17-023196
• OSTI ID: 4712509
• Journal Information: Soil Sci. Soc. Am. Proc., Journal Name: Soil Sci. Soc. Am. Proc. Vol. Vol: 26
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

AIR
BACTERIA
BARLEY
BIOLOGY AND MEDICINE
CEREALS
CONTAMINATION
ELECTRONS
ENZYMES
FUNGI
GAMMA RADIATION
MICROORGANISMS
PHOSPHATASES
PHOSPHATES
PHOSPHORUS
PLANTS
QUANTITY RATIO
RADIATION DOSES
RADIATION EFFECTS
ROOTS
SOILS
STERILIZATION
SURVIVAL TIME
TOMATOES
TOXICITY
UREA
UREASE
VARIATIONS
VEGETABLES
WATER
X RADIATION