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Nitrification Inhibitor Evaluation on Cotton. II. Inhibitor Incorporation Depth and N Placement 1
Author(s) -
York A. C.,
Tucker M. R.
Publication year - 1985
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1985.00021962007700030013x
Subject(s) - lint , trifluralin , nitrification , sowing , agronomy , malvaceae , chemistry , fiber crop , yield (engineering) , nitrogen , horticulture , biology , pesticide , materials science , metallurgy , organic chemistry
The use of nitrification inhibitors (NIs) in the Southeast has given inconsistent results. Because application techniques may affect the efficacy of NIs, a 3‐year experiment with cotton ( Gossypium hirsutum L.) was conducted on a sandy, low organic matter soil (Arenic Paleudults) to evaluate the efficacy of etridiazol [5‐ethoxy‐3‐(trichloromethyl)‐1,2,4‐thiadiazole] and nitrapyrin [2‐chloro‐6‐(trichlorometlyl) pyridine] when N was broadcast and deeply incorporated or applied as a 36‐cm band over the row surface. The NIs, tankmixed with trifluralin (α,α,α‐trifluor0‐2,6‐dinitro‐ N , N ‐dipropyl‐ p ‐to‐luidine) herbicide, were deeply incorporated with a disk prior to bed formation or shallowly incorporated with a rolling cultivar after bed formation. Regardless of N placement method or NI incorporation depth, neither inhibitor affected cotton yield, percent lint, fiber quality, or leaf N, P, K, Ca, Mg, Fe, Mn, Zn, Cu, or B contents. Split N applications, with one‐third at planting and the remainder sidedressed at the early square stage, increased N‐use efficiency in 2 of 3 years. Nitrogen placement did not affect cotton yield, fiber quality, or leaf nutrient content. Surface‐banding the N reduced stands by 9 to 20%. As compared to shallow incorporation, deep incorporation of trifluralin reduced cotton yield 6 to 17% and leaf K content at the peak flowering stage 7 to 24%, but did not affect fiber quality. Deep incorporation of trifluralin, combined with either surface‐banded N or application of all N at planting, reduced cotton stands in 2 of 3 years.