Journal or Publishing Institution: Weed Research
Study: http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3180.1977.tb00454.x/abstract
Author(s): Nomura, N.S. and Hilton, H.W.
Article Type: Peer Reviewed Study
Record ID: 1790
Abstract: The rate of aerobic evolution of 14CO2 from 14C‐glyphosate labelled in the methylphosphonyl carbon, varied 100‐fold within a group of five Hawaiian sugarcane soils. The rate depended inversely on the degree of soil binding, probably associated with the phosphonic acid moiety, and to a less certain extent on soil pH and soil organic matter. After an initial rapid degradation, the rate of 14CO2 evolution in three soils reached a constant at 16–21 days which continued to the 60‐day termination. The other two soils showed a continually decreasing rate throughout. Two soils released over 50% of the labelled carbon in 60 days, a third released 35%, while the remaining soils released 1.2 and 0.8% respectively.
Labelled carbon in the soils after 60 days consisted of glyphosate and one metabolite, aminomethyl‐phosphonic acid, with glyphosate predominating in high fixing soils. The14C could be extracted almost completely with NaOH solution, and remained mainly in solution after acidification.
Citation: Nomura, N.S. and Hilton, H.W., 1977. The adsorption and degradation of glyphosate in five Hawaiian sugarcane soils. Weed Research, 17(2), pp.113-121.
