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Laboratory Apparatus to Apply and Sample Anhydrous Ammonia in Bands
Author(s) -
Izaurralde R. C.,
Kissel D. E.,
Swallow C. W.
Publication year - 1986
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1986.03615995005000040021x
Subject(s) - anhydrous , sampling (signal processing) , ammonia , soil water , analytical chemistry (journal) , volumetric flow rate , chemistry , soil test , environmental science , soil science , mineralogy , chromatography , mechanics , optics , physics , organic chemistry , detector
To describe how soil properties affect anhydrous ammonia (NH 3 ) retention, more accurate laboratory methods are needed to apply anhydrous NH 3 in a line source (band) and sample the resulting NH 3 retention zone. We developed and tested a line‐source NH 3 applicator and a method for sampling the resulting NH 3 retention zone. The applicator has a system of flow control valves and a flow meter to regulate the rate of NH 3 flow to an injection needle. The needle is held stationary while NH 3 is injected into a box of soil. The box of soil moves on a platform whose speed can be varied to change the NH 3 application rate. The soil sampling method was to sequentially remove concentric cylindrical cores of increasing radii centered around the line of NH 3 injection. Ammonia was applied to two soils with different NH 3 retention capacities and the resulting NH 3 retention zones were sampled. Accurate NH 3 deliveries were possible with the system described. The coefficient of variation of the platform speed was <1%. The sampling method gave N recoveries that ranged between 95 to 99%. By using the concentric ring sampling method, ammoniacal‐N concentrations of duplicate retention zones at different distances from the injection line were not significantly different. Thus, the applicator and soil sampling method proved to be both accurate and precise for studying NH 3 retention zones in soil.