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Urea‐Formaldehyde as a Slowly Available Form of Nitrogen for Kentucky Bluegrass 1
Author(s) -
Kilian K. C.,
Attoe O. J.,
Engelbert L. E.
Publication year - 1966
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/agronj1966.00021962005800020026x
Subject(s) - formaldehyde , urea , urea formaldehyde , nitrogen , ammonium nitrate , ammonium , yield (engineering) , chemistry , nitrate , fertilizer , zoology , ammonia , agronomy , organic chemistry , materials science , biology , adhesive , layer (electronics) , metallurgy
A study was made of the effects of different ratios of N as urea‐formaldehyde to that as ammonium nitrate on the rate of growth, yield, and N recovery by Kentucky bluegrass. The largest total yield for the 3‐year experimental period from annual applications to the same plots was obtained for mixtures containing 53% or less of the N as urea‐formaldehyde. For N applications made only in the beginning, but with P and K added each year, total yields were significantly lower for mixtures containing 88 or 100% of their N in this form. These mixtures, however, gave the most uniform growth rate during each of the 3 years. The results indicate that as much as 50% of the N can be in the urea‐formaldehyde form without causing a reduction in yield. Recovery of added N was inversely related to the proportion of urea‐formaldehyde in the mixture, with values the first year ranging from 17% for urea‐formaldehyde to 50% for ammonium nitrate. Total N recovery for fertilizer applied annually to the same plot ranged from 23% for ureaformaldehyde to 51% for amonium nitrate, with the various mixtures giving intermediate values. The results suggest that urea‐formaldehyde can be topdressed on grass at rather heavy rates with the expectation that it will continue to release nitrogen over a period of several years.