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Full-Text Articles in Life Sciences
A Field Test Of The Wind Erosion Prediction System, Simon Van Donk, Edward L. Skidmore
A Field Test Of The Wind Erosion Prediction System, Simon Van Donk, Edward L. Skidmore
West Central Research and Extension Center, North Platte
Field data need to be collected to test wind erosion models under a broad range of climate, soil, and management conditions. The objective of this study was to test the USDA- ARS Wind Erosion Prediction System (WEPS) for a field with winter wheat plants in a modest amount of flat residue. A 600 m by 415 m field was selected near Burlington, CO, USA. Big Spring Number Eight (BSNE) samplers were used to measure wind blown sediment flux and automated devices (Sensits) for continuous detection of saltation. A weather station recorded relevant meteorological data. Detailed measurements of the field surface …
Development Of Hot/Cold Plate Apparatus For Determining Heat Transport Mechanisms In Mulch Materials, Simon Van Donk, Ernest W. Tollner, Stephen P. Mcdonald
Development Of Hot/Cold Plate Apparatus For Determining Heat Transport Mechanisms In Mulch Materials, Simon Van Donk, Ernest W. Tollner, Stephen P. Mcdonald
West Central Research and Extension Center, North Platte
To study the effects of mulches and crop residues on soil temperature, researchers have frequently used simulation models. In such models, quantification of heat transport within the mulch material is often weak and heat transport mechanisms are poorly understood. In this paper we describe an apparatus to quantify heat transport through dry mulch materials. In addition, heat transport mechanisms (conduction, thermal radiation, free and forced convection) can be identified and quantified using this apparatus. The apparatus consists of precisely controlled and monitored 0.9 m by 0.9 m hot and cold plates. The hot plate actually consists of three component plates: …
Review: Factors Affecting Decisions On When To Calve Beef Females, L. R. Sprott, Pas G.E. Selk, D. C. Adams
Review: Factors Affecting Decisions On When To Calve Beef Females, L. R. Sprott, Pas G.E. Selk, D. C. Adams
West Central Research and Extension Center, North Platte
The decision of when to calve beef females is critical to production efficiency and profitability in a cow and calf enterprise. Calf production and associated costs are affected by calving season because environmental conditions, stage of production, and season of the year interact to affect nutritional status and reproductive performance. Cow and calf producers typically choose to commence calving and breeding at times of the year when weather is least stressful and forage conditions are optimal. Choosing to do so can reduce the amount of supplemental feed needed to ensure acceptable pregnancy rates, resulting in reduced annual feed costs. However, …