Spatial Relation of Apparent Soil Electrical Conductivity with Crop Yields and Soil Properties at Different Topographic Positions in a Small Agricultural Watershed

Use of electromagnetic induction (EMI) sensors along with geospatial modeling provide a better opportunity for understanding spatial distribution of soil properties and crop yields on a landscape level and to map site-specific management zones. The first objective of this research was to evaluate the relationship of crop yields, soil properties and apparent electrical conductivity (ECa) at different topographic positions (shoulder, backslope, and deposition slope). The second objective was to examine whether the correlation of ECa with soil properties and crop yields on a watershed scale can be improved by considering topography in modeling ECa and soil properties compared to a whole field scale with no topographic separation. This study was conducted in two headwater agricultural watersheds in southern Illinois, USA. The experimental design consisted of three basins per watershed and each basin was divided into three topographic positions (shoulder, backslope and deposition) using the Slope Position Classification model in ESRI ArcMap. A combine harvester equipped with a GPS-based recording system was used for yield monitoring and mapping from 2012 to 2015. Soil samples were taken at depths from 0–15 cm and 15–30 cm from 54 locations in the two watersheds in fall 2015 and analyzed for physical and chemical properties. The ECa was measured using EMI device, EM38-MK2, which provides four dipole readings ECa-H-0.5, ECa-H-1, ECa-V-0.5, and ECa-V-1. Soybean and corn yields at depositional position were 38% and 62% lower than the shoulder position in 2014 and 2015, respectively. Soil pH, total carbon (TC), total nitrogen (TN), Mehlich-3 Phosphorus (P), Bray-1 P and ECa at depositional positions were significantly higher compared to shoulder positions. Corn and soybeans yields were weakly to moderately

Comparison of Terrain Indices and Landform Classification Procedures in Low-Relief Agricultural Fields

Landforms control the spatial distribution of numerous factors associated with agronomy and water quality. Although curvature and slope are the fundamental surface derivatives used in landform classification procedures, methodologies for landform classifications have been performed with other terrain indices including the topographic position index (TPI) and the convergence index (CI). The objectives of this study are to compare plan curvature, the convergence index, profile curvature, and the topographic position index at various scales to determine which better identifies the spatial variability of soil phosphorus (P) within three low relief agricultural fields in central Illinois and to compare how two methods of landform classification, e.g. Pennock et al. (1987) and a modified approach to the TPI method (Weiss 2001, Jenness 2006), capture the variability of spatial soil P within an agricultural field. Soil sampling was performed on a 0.4 ha grid within three agricultural fields located near Decatur, IL and samples were analyzed for Mehlich-3 phosphorus. A 10-m DEM of the three fields was also generated from a survey performed with a real time kinematic global positioning system. The DEM was used to generate rasters of profile curvature, plan curvature, topographic position index, and convergence index in each of the three fields at scales ranging from 10 m to 150 m radii. In two of the three study sites, the TPI (r ≥ -0.42) was better correlated to soil P than profile curvature (r ≤ 0.41), while the CI (r ≥ -0.52) was better correlated to soil P than plan curvature (r ≥ -0.45) in all three sites. Although the Pennock method of landform classification failed to identify footslopes and shoulders, which are clearly part of these fields’ topographic framework, the Pennock method (R² = 0.29) and TPI method (R² = 0.30) classified landforms that captured similar amounts of soil P spatial variability in two of the three study sites. The TPI and CI should be further explored when performing terrain analysis at the agricultural field scale to create solutions for precision management objectives

Transport of heat and mass in a two-phase mixture. From a continuous to a discontinuous description

We present a theory which describes the transport properties of the interfacial region with respect to heat and mass transfer. Postulating the local Gibbs relation for a continuous description inside the interfacial region, we derive the description of the Gibbs surface in terms of excess densities and fluxes along the surface. We introduce overall interfacial resistances and conductances as the coefficients in the force-flux relations for the Gibbs surface. We derive relations between the local resistivities for the continuous description inside the interfacial region and the overall resistances of the surface for transport between the two phases for a mixture. It is shown that interfacial resistances depend among other things on the enthalpy profile across the interface. Since this variation is substantial the coupling between heat and mass flow across the surface are also substantial. In particular, the surface puts up much more resistance to the heat and mass transfer then the homogeneous phases over a distance comparable to the thickness of the surface. This is the case not only for the pure heat conduction and diffusion but also for the cross effects like thermal diffusion. For the excess fluxes along the surface and the corresponding thermodynamic forces we derive expressions for excess conductances as integrals over the local conductivities along the surface. We also show that the curvature of the surface affects only the overall resistances for transport across the surface and not the excess conductivities along the surface.Comment: 25 pages, 2 figure

Letter from H. Williard to John Muir, 1905 Jnn 28.

PUBLISHINGDEPARTMENTA.C.M CLURG &. CO. 215-221 WABASH AVENUE. CHICAGO. June 28, 1905Mr. John Muir, Martinez, Calif. Dear Mr. Muir:- Since I returned from the Coast I have been very busily engaged in routine work, and until now have had no opportunity to make up for your daughter, Miss Helen, the print which I promised to send her. I have pleasure in forwarding it to her in your care, and hope it will arrive duly, and trust she may enjoy it. I have put in with the print one I just lately made of a hickory tree, which, being a photograph (and a rather good one at that) of a tree, I have thought you might enjoy having. I find also I have a good, print taken from near Rainbow Spring, on Mount Lowe, looking down the mountain, which it occurred to me you might enjoy having, inasmuch as it. is a quite typical illustration of the mountains of Southern California. This I have put in the package, and two copies of one of the negatives I made of yourself in your library. I confess these portraits are not very good, but perhaps they will interest you, as they are, I believe, unlike anything you have so far. Should you care for them, I would gladly send you some more prints of this portrait. Would you also greatly oblige me by giving Mrs. Muir the little landscape with mountains and river included in the package, together with my kind wishes. I have the most vivid recollection of the profitable and pleasant Sunday which I spent at your home in April, and also of the joyful little luncheon party participated in by yourself, Keith, Willis Polk and myself on the Monday following. I trust you will accept my kind regards, and I remainVery cordially yoursH. WillardDict. S.L.W.[in margin: Misc - Johnson Osborn Sargent [illegible]]0358

Soil Chemical Response to Experimental Acidification Treatments

One of the conclusions reached during the Congressionally mandated National Acid Precipitation Program (NAPAP) was that, compared to ozone and other stress factors, the direct effects of acidic deposition on forest health and productivity were likely to be relatively minor. However, the report also concluded “the possibility of long-term (several decades) adverse effects on some soils appears realistic” (Barnard et al. 1990). Possible mechanisms for these long-term effects include: (1) accelerated leaching of base cations from soils and foliage, (2) increased mobilization of aluminum (Al) and other metals such as manganese (Mn), (3) inhibition of soil biological processes, including organic matter decomposition, and (4) increased bioavailability of nitrogen (N)

The Revelation of God in the Revelation to St John

The question to which this present paper addresses itself is that concerning the nature of revelation as this is reflected in the Revelation to John. It asks whether God\u27s revelation in that writing is of Himself or of facts concerning Himself; what the source of the revelation is and in what manner it takes place; and whether revelation is an event of the past, the present, or the future. The Apocalypse is examined first to determine if its message can be clearly enough understood today to provide evidence for this investigation. The investigation then turns to the language describing revelation and the activity of revealing in the writing. Conclusions are drawn in the final chapter

Can We Innovate Our Way out of the Opioid Epidemic?

https://digitalcommons.misericordia.edu/research_posters2020/1016/thumbnail.jp

OHSU employee engagement with School of Dentistry services

OHSU Employee Engagement with School of Dentistry Services This project addresses low employee utilization of OHSU's School of Dentistry as a dental home, specifically the Faculty Dental Practice. This summary focuses on three critical areas for improvement: (1) an awareness campaign to increase knowledge and interest in the practice, (2) website optimization, and (3) reduced wait Co-authors: Das, Sanjoy Doherty, Moya Nicholson, Amy Tarley, Janett