Nitrogen starvation promotes biodegradation of N-heterocyclic compounds in soil

• Published in: Soil biology & biochemistry 2006-08, Vol.38 (8), p.2478-2480
• Main Author: Sims, G.K.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Ammonium; Atrazine; Biochemistry and biology; Biodegradation; Biological and medical sciences; Chemical, physicochemical, biochemical and biological properties; Cloransulam-methyl; corn; Fundamental and applied biological sciences. Psychology; Heterocyclic compounds; mineralization; Morrow plots; Nitrogen; nitrogen content; Physics, chemistry, biochemistry and biology of agricultural and forest soils; soil nutrients; Soil science; Zea mays
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/j.soilbio.2006.01.006

Mineralization studies were performed to examine the impact of N deprivation on microbial utilization of the N-heterocyclic herbicides, atrazine and cloransulam-methyl (C-M). Soil depleted by 130 years of cropping to Zea mays without fertilization was contrasted to soil from the same site regularly receiving fertilizers. Long-term N deprivation promoted rapid degradation of atrazine and the C-M pyrimidine ring, whereas no significant effect was observed on degradation of the C-M phenyl ring. When a sandy soil naturally low in N was used, addition of 5 or more μg NH 4–N/g soil suppressed mineralization of the C-M pyrimidine ring. These findings provide insight into organic N availability and suggest broad implications for the effect of exogenous N in degradation of heterocyclic herbicides.