Search Constraints

Start Over
Filtering by: Creator Hauck, M. Remove constraint Creator: Hauck, M. Degree Field Soil Science Remove constraint Degree Field: Soil Science Resource Type Dissertation Remove constraint Resource Type: Dissertation

Search Results

  • Nitrogen release from granules of sulfur-coated urea

    Creator:
    Jarrell, Wesley M.
    Abstract:
    Sulfur-coated urea (SCU) is a slow release nitrogen fertilizer manufactured by the Tennessee Valley Authority. Urea granules are sprayed with molten sulfur, then holes in the sulfur coating are sealed with a layer of wax sealant. The sulfur coatings are mixtures of amorphous and crystalline allotropes of sulfur. Coating thickness...
    Resource Type:
    Dissertation
    Full Text:
    granules of SCU-31. The general form of the equation is mr = 1.0 B M exp(-k 3T). 4. Benzene treatments for

  • Role of a grass riparian zone in controlling the fate of nitrogen in a poorly drained agricultural landscape

    Creator:
    Davis, Jennifer H.
    Abstract:
    Riparian ecosystems, through their unique positions in the agricultural landscape, have the potential to mitigate nutrient loading to streams. This study was conducted to gain a better understanding of N cycling in a poorly drained Grass Riparian Zone (GRZ) and adjacent Perennial Ryegrass seed Field (PRF) in the Willamette Valley,...
    Resource Type:
    Dissertation
    Full Text:
    that was not processed in the PRF entered the GRZ, it was consumed within 6 m in shallow soil water

  • Nitrogen available to winter wheat as influenced by previous crop in a moist xeric environment

    Creator:
    Qureshi, Maqsood Hassan
    Abstract:
    Rotating wheat with other crops is a common practice in the Willamette Valley of western Oregon. Depending upon previous crop and soil type, current N fertilizer recommendations for wheat in the Willamette Valley vary widely. Excessive fertilizer poses environmental risk, whereas lower N inputs than required by the crop represent...
    Resource Type:
    Dissertation
    Full Text:
    . Fresenius' J. Anal. Chem. 338: 394- 398. Hauck, R. D., and J. M. Bremner. 1976. Use of tracers for soil and

  • Cover crops and biochemical functional diversity in relation to nitrogen availability in soil

    Creator:
    Burket, John Zimmerman
    Abstract:
    Nitrogen availability in agricultural soils from fertilizer, plant residue inputs, and soil organic matter has important implications beyond crop yield. Legume winter cover crops and one fourth the recommended N rate on sweet corn resulted in yields equivalent to those at the recommended rate in the Willamette Valley of western...
    Resource Type:
    Dissertation
    Full Text:
    fertilization. Soil Sci. Soc. Am. J. 57: 1034-1040. Campbell, C. A., K. E. Bowren, M. Schnitzer, R. P. Zentner

  • Urea release from sulfur-coated urea and nitrogen utilization by tall fescue

    Creator:
    Pettygrove, G. Stuart
    Abstract:
    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...
    Resource Type:
    Dissertation
    Full Text:
    first major profes- sor, Dr. M. D. Dawson is also greatly appreciated. Dr. L. Boersma is to be thanked

  • The Impact of Freeze-Thaw Cycles to the Physical and Biogeochemical Properties of Alaskan Permafrost Soils

    Creator:
    Rooney, Erin C.
    Abstract:
    Arctic warming is exposing thawing permafrost to repeated freeze-thaw, a disruptive process that can alter soil biogeochemistry and physical structure. To investigate the impact of permafrost exposure to freeze-thaw, soil response was tested across three scales: 2.5 cm³ aggregates, a forested hillslope, and two sites at contrasting latitudes. XCT imaging...
    Resource Type:
    Dissertation
    Full Text:
    Colombo, Francesca Poratelli, Christian Hauck, and Christin Hilbich for their expertise and mentorship