Consequences of banding nitrogen fertilizers in soil

Abstract

SUMMARYAn account is given of the iilteractions which occur when urea or ammonium sulphate is banded in a clay soil. The spatial distribiltions of ammonium, nitrate, and nitrite around the band are given as functions of time and are discussed in relation to results from a series of Jncubations of homogeneous mixtures of various nitrogen compounds and soll. The ditIusion of the banded fertilizers and their products throilgh the soil presents the nitrifying organisms with a wide range of environments. The patterns of nitrification are therefore complicated. Nevertheless, they are explicable in terms of the main results of the incubations which were that (a) nitrification was completely inhibited if the osmotic suction of the soil solution was hJgher than t0 bars, if the ammonium-N conceiltration in the soil solution was above 3000 ppm, or if the pH was greater than 8, (b) nitrite accumulated if the pH was between 7 and 8, (c) nitrate accumulated if the pH was less than 7, and (d) above a minimum concentration of Iertilizer the rate of nitrate formation was independent of the concentration unless the latter was so high that either pH, osmotic suction or ammonium concentration became inhibitory.An agronomic implication of the work is that if a given amount of fertilizer is applied to a given area of soll, the rate of nitrate formation per unit area may be controlled by banding the fertilizer and varying the band spacing.

Effect of fertilizer nitrogen management on N2O emissions in commercial corn fields

“…The reason for this effect is not clear. Fertilizer banding is known to inhibit nitrification (Wetselaar et al 1972). Despite this inhibition, soil nitrate concentrations were higher for the S150 treatment than for the S75 treatment, and there was limited evidence that N 2 O emissions were nitrate limited; therefore, the reduced N 2 O emissions for the S150 treatment cannot be attributed to a reduced nitrate supply as a result of inhibition of nitrification.…”

“…This primarily reflects the delay in fertilizer N application for the S150 treatment, but also likely reflects the difference in application method (broadcast vs. band). Banding of fertilizer N inhibits the nitrification process (Wetselaar et al 1972), and elevated soil NH 4 -N concentrations have been reported to persist after fertilizer banding (Zebarth et al 1999). Sidedress application of fertilizer N at the six-leaf stage is, therefore, an effective means of reducing nitrate intensity in corn production, even if the same rate of fertilizer N is applied.…”

Urease activity in soils : a review

“…137 Bezdicek et al13= compared the behaviour of urea, diammonium phosphate and ammonium sulfate in an alkaline soil. They found that the highest accumulation of nitrite (260ppm) occurred in the soil to which urea had been added.…”

Nutrient losses to soil from field storage of solid poultry manure

“…4). Wetselaar et al (1972) found that nitrification was inhibited when soil ammonium-N concentrations exceeded 3000 mg N kg -1 soil under near neutral soil pH values. Assuming a soil pH of 7, and similar conditions as in Fig.…”