The Formation of Nitrate from Ammonium Nitrogen in Soils: IV. Use of the Delay and Maximum Rate Phases for Making Quantitative Predictions

Estimation of the amount of nitrate accumulation occurring in soil requires an understanding of the delay period and maximum rate of nitrate accumulation under defined environmental conditions. The actual maximum rates and delay periods of nitrate accumulation varied greatly between soils at several constant temperatures, whereas the relative maximum rates and delay periods were more nearly constant at any one temperature. An equation for estimating nitrate accumulation, which includes maximum rate and delay indexes, is suggested. Temperature‐rate and temperature‐delay indexes are presented for several soils. Values for different temperatures were predicted from actual values determined at only one temperature. The concept of delay periods and maximum rates should help evaluate the influence of other factors on nitrate accumulation.