description of the general effect of pH on formation of nitrate in soils

• Published in: Journal of plant nutrition and soil science 1999, Vol.162, p.549-556
• Main Author: Olness, A
• Format: Article
• Language: English
• Subjects: agricultural soils; chemical concentration; fertilizer application; hydrogen; hydroxides; ions; mathematical models; mineralization; nitrate nitrogen; nitrates; nitrogen; silt loam soils; soil chemistry; soil pH; Zea mays
• ISSN: 1522-2624; 1522-2624
• DOI: 10.1002/(sici)1522-2624(199910)162:5<549::aid-jpln549>3.0.co;2-k

Soil [H+] and [OH-] have a major effect on the rate of microbial mineralization of organic matter and the subsequent expression of nitrate-N (NO-3-N). The objective of this work is a mathematical description of the effect of [H+] and [OH-] on expression of NO-3-N from soil organic matter. Data obtained from the Cooperative States Research Service North Central Regional Committee-201 study were analyzed for effects of [H+] and [OH-] on expression of NO-3-N. Soil samples were collected in the 12-state Cornbelt Region (USA) during a 4-year period following a uniform protocol. Samples were taken immediately before or during planting and again at the V-5 growth stage of maize and analyzed for NO-3-N. The change in [NO-3-N] in the surface 0- to 30-cm of soil during pre-plant to V-5 growth stage of corn was estimated. Data were used only from sites receiving 8.5. Application of a general energy model for limited systems showed greater sensitivity of NO-3-N production to [OH-] than to [H+]. Field observations show that gains of > 300 kg or losses of > 80 kg of NO-3-N ha-1 can occur in periods of about 60 days.