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Physical Sciences and Mathematics Commons

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Full-Text Articles in Physical Sciences and Mathematics

Monitoring Subsurface Drainage Flow At Remote Locations, Stephen R. Workman, Stephen F. Higgins, Scott A. Shearer Nov 2001

Monitoring Subsurface Drainage Flow At Remote Locations, Stephen R. Workman, Stephen F. Higgins, Scott A. Shearer

Biosystems and Agricultural Engineering Faculty Publications

Laboratory evaluations and field results are presented for a slotted weir used to measure discharge from subsurface drains. The head–discharge curve for the vertical slot is a simple power function with an exponent of 1.5. There was excellent agreement (r2 > 0.99 and 1:1 slope) between predicted and observed discharge in laboratory testing of 12 test weirs representing five slot widths. The primary advantages of the vertical slot weir are its simplicity, ease of maintenance, and ability to measure small flow rates. Disadvantages include a tendency for the slot to close a small amount over time as a result of …


Management Of Soil Organic Matter And Gypsum For Sustainable Production In The Carnarvon Horticultural District Of Western Australia, R.S.B. Greene, A.J. Lin, D. C. Parr Mar 2001

Management Of Soil Organic Matter And Gypsum For Sustainable Production In The Carnarvon Horticultural District Of Western Australia, R.S.B. Greene, A.J. Lin, D. C. Parr

Agriculture reports

Soil quality is critically important for the long-term production of high quality and high yielding fruit and vegetable crops in the Carnarvon horticultural district of Western Australia. A stable soil structure is essential for good soil quality.


Composting Of Feedlot And Dairy Manure: Compost Characteristics And Impact On Crop Yields, Galen E. Erickson, Terry J. Klopfenstein, Walker Luedtke, Mark Schroeder, Charles A. Francis, Gary Lesoing Jan 2001

Composting Of Feedlot And Dairy Manure: Compost Characteristics And Impact On Crop Yields, Galen E. Erickson, Terry J. Klopfenstein, Walker Luedtke, Mark Schroeder, Charles A. Francis, Gary Lesoing

Nebraska Beef Cattle Reports

Since 1993, approximately 17,600 tons of beef feedlot and dairy compost have been spread on 1,100 acres. Crop yields were measured to determine the impact of a one-time compost application by using no-compost check strips in large-scale production fields. Adding compost to irrigated corn, irrigated soybeans, and dryland corn acres significantly increased yields, with four-year average increases of 2.3, 1.5, and 2.7%, respectively. For all crops measured, the response to compost was greatest the first year following application and declined linearly in subsequent years. The increased yield from compost application offsets spreading costs using average prices for crops.