The Effect of Ammonia and Ammonia-sulfur Solutions on Nitrification Rates and Chemical Properties of a Calcareous Soil1
- R. G. Stevens and
- J. O. Reuss2
Nitrification rates and changes in chemical properties of a calcareous soil were investigated after injection of liquid anhydrous NH3 and anhydrous NH3-S solutions.
Nitrification rates (on a whole pot basis) of 15.7, 25.3, and 32.2 mg of N per pot per day were found with the application of 200, 400, and 600 mg of N/pot, respectively. These nitrification rates were recorded during the initial 14 days of the study when total NO3- accumulation appeared to be linear.
Ammonium depletion from zones 1 cm in thickness measured outward from the injection point appear to obey a first-order rate law. Half life values ranged from 12.4 to 1.4 days. They were longest at the injection point with the highest NH3 rate and decreased with decreasing rate of application and with increasing distance from the injection point. There were no differences in the nitrification rates of the two sources as measured by either nitrate accumulation on a whole pot basis or ammonium depletion of individual zones.
Less than 10% of the applied sulfur was recovered as SO42- during the incubation period. Little difference was found in the effect of the two sources on pH, DTPA extractable Zn or Fe, or NaHCO3 extractable P. DTPA-extractable Mn was higher near the injection point in the NH3-S treatments.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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