Premium
The Fate of Nitrogen from Injected Liquid Manure in a Silt Loam Soil
Author(s) -
Comfort S. D.,
Kelling K. A.,
Keeney D. R.,
Converse J. C.
Publication year - 1988
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1988.00472425001700020027x
Subject(s) - loam , manure , nitrification , leaching (pedology) , chemistry , zoology , nitrogen , liquid manure , soil water , environmental chemistry , environmental science , agronomy , soil science , biology , organic chemistry
A field experiment was conducted on a Piano silt loam (Typic Argiudoll) in southcentral Wisconsin to monitor N transformations following liquid manure injections. Liquid manure with and without a nitrification inhibitor [nitrapyrin, 2‐chloro‐6‐(trichloromethyl)pyridine, 13 mg a.i. L −1 liquid manure] was injected into an uncropped area in June 1985. Soil samples were taken using a grid placed over the vertical cross‐section of the injected bands permitting spatial sampling in the vertical plane. Sampling was done 5, 12, 26, 39, 67, 99, and 350 d after manure application by progressive exposure of the band. Soil water content, pH, NH 4 ‐N, (NO 2 + NO 3 )‐N, Cl, and water‐soluble C were determined. The synagraphic computer program, SYMAP, was used to evaluate spatial changes in inorganic N concentrations in the manure injection zone. Nitrapyrin was not effective in inhibiting nitrification at the rate used. Nitrification occurred at the outer fringes of the band within 5 d; maximum concentrations of 300 to 800 mg NO 3 ‐N kg −1 occurred throughout the injection zone at 26 d. High respiratory activity in the injection zone was indicated by an almost threefold decrease in water‐soluble C between day 5 (750 mg C kg −1 ) and day 12 (270 mg C kg −1 ). Water content remained higher than the surrounding soil in the injection zone for 99 d. Once NO 3 leaching occurred, NO 3 ‐N/Cl ratios decreased with depth under the injection zone. The abundant supply of NO 3 and readily oxidizable C, combined with the high moisture environment, led to the conclusion that liquid manure injections created an environment conducive for denitrification.