Effect of urease inhibitors and cationic materials on growth response and ammonia volatilization following fertilization of Kentucky bluegrass (Poa pratensis L.) with urea

1987 ◽  
Author(s):  
Young Kyoo Joo
HortScience ◽  
1991 ◽  
Vol 26 (5) ◽  
pp. 537-539 ◽  
Author(s):  
Young K. Joo ◽  
Nick E. Christians ◽  
John M. Bremner

We evaluated the response of Kentucky bluegrass (Pea pratensis L.) turf to urea amended with the urease inhibitors PPD, NBPT, and ATS and with the cations K+ (KCl) and Mg+2 (MgCl2). Treatments for the 2-year field experiment included liquid urea applied monthly in June to Sept. 1985 and 1986 at 49 kg N/ha with PPD (1%, 2%, 3% by weight of applied N), NBPT (0.5%, 1%, 2%), ATS (5%, 15%, 25%), K+ (5%, 15%, 25%), and Mg+2 (5%, 15%, 25%). The NBPT was included only in the 1986 field study. The Mg+2 and K+ reduced foliar burn and increased turf quality during mid- and late Summer 1985 at the 5% rate, but clipping yield was not affected by any treatment. In 1986, under milder climatic conditions, PPD and NBPT increased clipping yield by 13.2% and 15.2%, respectively. At the 15% rate, ATS increased clipping yield by 15.1%, but, on average, PPD and NBPT were much more effective. Chemical names used: phenylphosphorodiamidate (PPD), N-(n -butyl) thiophosphoric triamide (NBPT), and ammonium thiosulfate (ATS).


2018 ◽  
Vol 36 (3) ◽  
pp. 85-91
Author(s):  
Maxim J. Schlossberg ◽  
Benjamin A. McGraw ◽  
Kyle R. Hivner

Abstract Easy handling and low unit N cost make prilled urea (46-0-0) a popular fertilizer. While incomplete recovery of granular urea applications by turfgrass is documented, practical guidance for small-plot field assessment of ammonia (NH3) volatilization remains limited. Our objectives were to (i) develop a method for field-implementation of closed flux/dynamic chambers to measure ammonia emission over a 3-day period following granular urea application to turfgrass, and (ii) infer the significance of said measures to levels arising from simultaneous static-chamber measures. A Kentucky bluegrass (Poa pratensis L. ‘Midnight’) lawn was treated with granular urea-N at a rate of 0 or 43 kg.ha−1 (38 lb/A) twice in both 2014 and 2015. Flux chamber measures of mean ammonia volatilization from urea-N fertilizer applied 3 days previous exceeded simultaneous static chamber measures by a factor of 17. Relative to static, the closed dynamic/flux chamber system described affords a more precise and efficient method for measuring ammonia volatilization from small field plots. Furthermore, over a 3-day period of dry conditions and ambient temperatures fluctuating between 10 and 31 C (50 and 88 F), as much as 23.1% of a granular urea application broadcast over a Kentucky bluegrass lawn can be volatilized as ammonia. Index words: flux, gaseous emissions, methods, nitrogen, static, turfgrass. Species used in this study: ‘Midnight' Kentucky bluegrass (Poa pratensis L.).


1979 ◽  
Vol 25 (10) ◽  
pp. 1197-1200 ◽  
Author(s):  
R. C. Shearman ◽  
W. L. Pedersen ◽  
R. V. Klucas ◽  
E. J. Kinbacher

Associative nitrogen fixation in Kentucky bluegrass (Poa pratensis L.) turfs inoculated with five nitrogen-fixing bacterial isolates was evaluated using the acetylene reduction assay and nitrogen accumulation as indicators of fixation. 'Park' and 'Nugget' Kentucky bluegrass turfs were grown in controlled environment chambers and inoculated with Klebsiella pneumoniae (W-2, W-6, and W-14), Erwinia herbicola (W-8), and Enterobacter cloacae (W-11). 'Park' inoculated with K. pneumoniae (W-6) had significant acetylene reduction activity using undisturbed turfs. Other treatments including turfs treated with heat-killed cells had no significant difference in acetylene reduction. In a second study, 'Park' and 'South Dakota Certified' turfs were grown in a greenhouse and inoculated with K. pneumoniae (W-6) and E. herbicola (W-8). 'Park' inoculated with K. pneumoniae (W-6) had increased acetylene reduction activity rates and also a greater nitrogen accumulation in aerial tissues when compared to controls. Acetylene reduction activity was correlated (r = 0.92) to nitrogen accumulation. Other treatments did not effectively increase acetylene reduction activity or nitrogen accumulation.


1981 ◽  
Vol 27 (1) ◽  
pp. 52-56 ◽  
Author(s):  
L. V. Wood ◽  
R. V. Klucas ◽  
R. C. Shearman

Turfs of 'Park' Kentucky bluegrass reestablished in the greenhouse and inoculated with Klebsiella pneumoniae (W6) showed significantly increased nitrogen fixation (acetylene reduction) compared with control turfs. Mean ethylene production rates per pot were 368 nmol h−1 for K. pneumoniae treated turfs, 55 nmol h−1 for heat-killed K. pneumoniae treated turfs, and 44 nmol h−1 for untreated turfs. Calculated lag periods before activity was observed were generally very short (less than 1 h).When 'Park' Kentucky bluegrass was grown from seed on soil-less medium of Turface, a fired aggregate clay, inoculation with K. pneumoniae (W6) resulted in 9 of 11 turfs showing nitrogenase activity (mean ethylene producion rate per pot was 195 nmol h−1). Only 3 of 11 turfs treated with heat-killed K. pneumoniae showed any activity and their mean rate of ethylene production (40 nmol h−1 per pot) was significantly lower than that for turfs treated with K. pneumoniae.Using the 'Park'–Turface soil-less model system it was shown that acetylene reducing activity was (i) root associated, (ii) generally highest at a depth of 1–4 cm below the surface, (iii) enhanced by washing excised roots, and (iv) inhibited by surface sterilization of excised roots. Klebsiella pneumoniae was recovered from Turface and roots showing acetylene reducing activity.


1979 ◽  
Vol 59 (2) ◽  
pp. 469-473 ◽  
Author(s):  
R. G. INGRATTA ◽  
G. R. STEPHENSON ◽  
C. M. SWITZER

Optimum top growth of annual bluegrass (Pao annua L.) and Kentucky bluegrass (Poa pratensis L.) was obtained at 24/12 °C day/night temperature regime in controlled environment studies. The tolerance of seedling Kentucky bluegrass to linuron [3-(3,4-dichlorophenyl)-1)methylurea] appeared to be greatest at this temperature regime when photoperiods were 16 h in length. A granular formulation of linuron gave excellent control of annual bluegrass in Kentucky bluegrass turf at 6.7 kg/ha when applied postemergence. At this rate, all culitivars of Kentucky bluegrass tested, with the exception of Fylking, were tolerant to linuron as a granular formulation. After application of linuron at 3.4–6.7 kg/ha, phytotoxic residues remained in the soil at sufficient levels to injure seedling Kentucky bluegrass for up to 3 mo.


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