Ammonia (NH₃) volatilization and loss from nitrogen (N) fertilizer in agriculture negatively impacts crops, farm profitability, human health and surrounding ecosystems where it is deposited. A significant source of NH₃ volatilization occurs from surface application of urea on sandy soils with low pH buffering capacity such as those in the...
Ammonia (NH₃) volatilization can result in a substantial amount of surface applied nitrogen (N) being lost into the atmosphere, making it an environmental pollutant as well as reducing plant-available N. However, N can also be easily lost from the soil through leaching,
and nitrous oxide (NO₂). Enhanced efficiency N fertilizers...
Grass seed production in Oregon's Willamette Valley traditionally relied on open field burning for straw residue disposal and nutrient recycling. Changes in residue management from open field burning to methods that remove straw coincided with rapidly declining K soil test values. A survey of grass seed fields showed that many...
Nitrogen can be lost when the quantity of available nitrogen exceeds crop demand or nitrogen availability is not in synchrony with crop demand. Either situation results in accumulation of available nitrogen, primarily in the nitrate form, at the end of the growing season. Over-winter nitrogen loss occurs primarily as nitrate-...
The purpose of this report is to document changes
resulting from long-term application of biosolids to
grazed dryland pasture. The report contains two chapters:
• Chapter 1: Biosolids Increase Grass Yield and Quality
in Dryland Pasture
• Chapter 2: Biosolids Increase Soil Fertility in Dryland
Pasture
Data summarized here was...
Credits for available N from past manure applications are often used in nutrient management planning. However, it is difficult to verify the accuracy of these credits. The major objective of this study was to estimate long-term effects of manure application on soil N mineralization. Specific objectives were to: 1) estimate...
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...
Previous studies indicated that fertigating with nitrogen (N) was more effective than using granular N fertilizers in production of northern highbush blueberry (Vaccinium corymbosum L.). To build on these findings, four studies were conducted in western Oregon to determine whether fertigation was also an effective method for applying other nutrients,...
Interest in measuring soil quality continues to increase worldwide in view of demands on land productivity and the necessity to preserve soil resources, yet identification of suitable indicators for soil quality assessment is still evolving. This study adapted 10 biological, physical, and chemical indicators of soil quality identified by the...
Five boron rates and seven water levels were applied
to bush green beans (Phaseolus vulqaris cv Oregon 91G) and
to cauliflower (Brassica olereacea var. botrytis, cultivar
"Snowball Y") in 1989 and 1990 to evaluate their effects on
total yield of both crops and on outer quality, head
hollowness and internal...