Cristine Morgan

Visible and near-infrared (VNIR, 400–2500 nm) diffuse reflectance spectroscopy (DRS) is a rapid, proximal-sensing method that has proven useful in quantifying constituents of dried and ground soil samples. Very little is known, however, about how DRS performs in a field ...

Soil bulk density affects water storage, water and nutrient movement, and plant root activity in the soil profile. Its measurement is difficult in field conditions. Vibration-induced conductivity fluctuation was investigated to quantify soil bulk density with possible field applications in the future. The AC electrical conductivity of soil was measured using a pair of blade-like electrodes while exposing the soil

Direct determination of soil hydraulic properties is often costly and laborious hence the use of indirect methods such as pedotransfer functions (PTFs). Despite progress made in PTF development in general, little evaluation of PTFs has been done for the sandy soils of Niger. We tested the ability of three PTFs, (Campbell, van Genuchten, and Vauclin) to determine soil water retention

... Lowering fertilization rates in these areas that are over fertilized could reduce leaching and still achieve similar yields (Vanotti and Bundy, 1994). ... Site Description. A 30.4-ha privately owned field located in Dane County near Waunakee, WI, was used in this study. ...

Visible and near-infrared (VNIR, 400–2500 nm) diffuse reflectance spectroscopy (DRS) is a rapid, proximal-sensing method that has proven useful in quantifying constituents of dried and ground soil samples. Very little is known, however, about how DRS performs in a field ...

... Erath County contained 117-dairy confined animal feeding opera-tions in October 2005, with ... spatial variability of P across dairy landscapes vital for developing effective best managementpractices. ... The next question follows: Do the current sampling intensity and soil test P (STP ...

... In some cases where the soil was high in clay, the piano wire did smear the soil face, but smearing was minimal compared to the purposefully smeared samples. Both halves of each core, smeared and unsmeared, were scanned at field-moist water content. ...

... a Department of Natural Resources and Environmental Management, Ball State University,Muncie, IN 47306, USA. b Soil & Crop Sciences Department, Texas A&M University, 370 Olsen Boulevard, College Station, TX 77843-2474, USA. ...

ABSTRACT Visible and near-infrared spectral data were used to predict the higher heating value (HHV) and dry, ash-free HHV (HHVdaf) of solid manure samples collected from cattle fed diets containing wet distillers grains plus solubles (WDGS) in 0%, 15%, 30%, 45%, and 60% dry matter concentrations. The HHV was determined by isoperibol bomb calorimetry and the HHVdaf was calculated from an equation based on the HHV and proximate analysis. Spectral models were developed in “The Unscrambler” software. The spectral models based on all treatments with random samples withheld for validation predicted the HHV with excellent reliability within 1.7%; RMSD = 60.19 cal g−1 (108 Btu lb−1), RPD = 2.29 (excellent), and bias = −15.29 cal g−1 (28 Btu lb−1), using five PLS factors and identifying 129 important wavebands. Accounting for estimated N and S content reduced the predictive accuracy of the spectral models by 0.1% with an RPD = 2.28 (excellent). Spectral models based on all treatments with random samples withheld for validation predicted the HHVdaf with acceptable reliability within 2.0% with an RMSD = 96.17 cal g−1 (173 Btu lb−1), RPD = 1.17 (acceptable), and bias = −19.83 cal g−1 (−37 Btu lb−1), using five PLS (partial least squares) factors and identifying 29 important wavebands. Spectral models reliably predicted the HHV of feedlot manure with accuracy well under the 5% error margin tolerated in practical applications such as feedlot manure gasification.

Biogeographers emphasize the presence of scale-dependence in vegetation–environment relationships. This research addresses the issue of scale-dependence, focusing on spatial correspondence of floristic and edaphic gradients across salt marsh creeks at Skallingen, Denmark. We employed a hierarchical approach, which compared vegetation and soil gradients at both fine and coarse scales. At the fine scale, we used ordination techniques to identify the

Both recent models and historical events such as the Dust Bowl and volcanic eruptions have illustrated aerosols can play a significant role in climate change through direct and indirect optical effects. Soil dust aerosols generated by Aeolian processes represent a significant fraction of the total mass burden of atmospheric particles. Central to a better understanding of the climate effects of