Following the surface application of urea to soil, there is the potential for nitrogen (N) loss from ammonia (NH3) volatilization until sufficient rain or irrigation has moved it into the soil. Many studies measuring NH3 loss have used laboratory and microplot field studies. The limitation of these techniques is that...
Following the surface application of urea to soil, there is the potential for nitrogen (N) loss from ammonia (NH3) volatilization until sufficient rain or irrigation has moved it into the soil. Many studies measuring NH3 loss have used laboratory and microplot field studies. The limitation of these techniques is that...
A growth chamber experiment was conducted to determine the
rate of S-urea mineralization and effect of S-urea on the yield of
ryegrass (Lolium multiflorum) grown in Steiwer soil as influenced
by soil temperature (60, 75, and 90° F) and soil moisture stress
(0. 10, 0.35, and 2.50 bars). Plant yield,...
Sulfur-coated urea (SCU), a slow release nitrogen fertilizer,
may be economically competitive with conventional fertilizers, but
little is known of the mechanism of urea release from SCU and the
environmental factors which affect the urea release rate. Objectives
of this thesis were: (1) to determine factors which affect the rate...
The effect of canopy orientation on fruiting performance of 'Beurre
d'Anjou' pears (Pyrus communis L.) and postharvest urea spray on ovule
longevity and fruit set of 'Doyenne du Comice' pears were studied.
Hedgerows of 'Beurre d'Anjou' pear trees planted in 1969 in two
orientations north-south (N-S) and east-west (E-W) were...
Three rates of urea, urea-DCD, and NH₄N0₃ were soil applied in April and August 1986 to strawberry selection OR-US 4930 and cultivar 'Sumas' to determine effects of the nitrification inhibitor dicyandiamide (DCD) and nitrogen source and rate on soil NH₄ and N0₃ levels, fruit yield and quality, and mineral composition...
Preliminary fertilization trials with western hemlock have yielded responses which vary significantly from stand to stand, especially in areas near the Pacific Coast. Growth responses have varied from positive to negative in an erratic manner. Previous data did not permit validation of such hypotheses as, "the application of fertilizer
to...