Wrap up and Validation of the Yield Forecast Project for 2015

During the 2015 growing season, a group of scientists from the Department of Agronomy ran a pilot project with the objective of forecasting end-of-season yields and in-season water and nitrogen dynamics (crop demand and soil supply). In-season updates were put in past ICM News articles (June 17th, July 31st, and August 14th). Briefly, this project combined the use of a cropping systems model (APSIM), a climate model (WRF), and high-resolution, in-season measurements to create the forecasts. The project focused on eight cropping systems in 2015: two sites (Ames and Sutherland), two crops (corn and soybean), and two planting dates of each crop. More details can be found in a previous ICM News article with plot management details from June 17, 2015. In this article we’ll present validation results of our last forecast on September 12

Above- and Below-ground Biomass Production in Corn and Prairie Bioenergy Cropping Systems

The Comparison of Biofuel Systems (COBS) project is a long-term, 20-acre field experiment designed to provide quantitative, side-by-side comparisons of corn- and prairie-based biofuel feedstock production systems with respect to biomass yields, liquid fuel potential, and multiple environmental impacts. Here, we report on above- and below-ground biomass production from selected treatments

Integration of a microprobe into a CMM

Various microprobes have been developed in the last decade to address the needs of micrometrology. However, most microprobes are only employed in specialized measuring machines located in a few research institutes and are not widespread in the industry. This work aims to extend the capabilities of conventional coordinate measuring machines (CMMs) towards measuring microgeometries through the low-cost integration of a tactile microprobe. In order to demonstrate this, a gear measuring instrument (GMI), which is a commercial CMM not specialized for measurements at the microscale, has been equipped with a recently developed silicon-membrane-based microprobe. In the first part of this work, the working principle of the microprobe, its assembly and its integration into the GMI are described. Two different mounting setups of the microprobe onto the GMI were evaluated and tested. Measurements on the GMI were performed solely with the microprobe or by combining the microprobe and the measurement system already present on the GMI. This combination makes it possible to use the microprobe advantageously and to exchange it in a comfortable semi-automatic way. To test these two mounting setups, a new involute scanning artifact (SAFT) with superimposed waviness was measured

Age-related collagen turnover of the interstitial matrix and basement membrane: Implications of age- and sex-dependent remodeling of the extracellular matrix

The extracellular matrix (ECM) plays a vital role in maintaining normal tissue function. Collagens are major components of the ECM and there is a tight equilibrium between degradation and formation of these proteins ensuring tissue health and homeostasis. As a consequence of tissue turnover, small collagen fragments are released into the circulation, which act as important biomarkers in the study of certain tissue-related remodeling factors in health and disease. The aim of this study was to establish an age-related collagen turnover profile of the main collagens of the interstitial matrix (type I and III collagen) and basement membrane (type IV collagen) in healthy men and women. By using well-characterized competitive ELISA-assays, we assessed specific fragments of degraded (C1M, C3M, C4M) and formed (PINP, Pro-C3, P4NP7S) type I, III and IV collagen in serum from 617 healthy men and women ranging in ages from 22 to 86. Subjects were divided into 5-year age groups according to their sex and age. Groups were compared using Kruskal-Wallis adjusted for Dunn's multiple comparisons test and Mann-Whitney t-test. Age-specific changes in collagen turnover was most profound for type I collagen. PINP levels decreased in men with advancing age, whereas in women, the level decreased in early adulthood followed by an increase around the age of menopause (age 40-60). Sex-specific changes in type I, III and IV collagen turnover was present at the age around menopause (age 40-60) with women having an increased turnover. In summary, collagen turnover is affected by age and sex with the interstitial matrix and the basement membrane being differently regulated. The observed changes needs to be accounted for when measuring ECM related biomarkers in clinical studies

Plant Litter Quality Affects the Accumulation Rate, Composition, and Stability of Mineral-associated Soil Organic Matter

Mineral-associated organic matter (MAOM) is a relatively large and stable fraction of soil organic matter (SOM). Plant litters with high rates of mineralization (high quality litters) are hypothesized to promote the accumulation of MAOM with greater efficiency than plant litters with low rates of mineralization (low-quality litters) because litters with high rates of mineralization maximize the synthesis of microbial products and most MAOM is microbial-derived. However, the effect of litter quality on MAOM is inconsistent. We conducted four repeated short-term incubations (46-d each) of four plant litters (alfalfa, oats, maize and soybean) in two low-carbon subsoils (sandy loam and silty loam) with and without nutrient addition. Our short-term incubations focused on the initial stage of litter decomposition during the time when litter quality has a measureable effect on mineralization rates. Plant litter quality had a much greater effect on litter-C mineralization rate and MAOM-C accumulation than did soil type or nutrient addition. Soils amended with high-quality oat and alfalfa litters had greater MAOM-C accumulation than soils amended with low-quality maize and soybean litters. However, soils amended with high-quality litters also had greater litter-C mineralization than soils amended with low-quality litters. As a result, the accumulation of MAOM-C per unit of litter-C mineralization was lower in soils amended with high-vs. low-quality litters (0.65 vs. 1.39 g MAOM-C accumulated g−1 C mineralized). Cellulose and hemicelluose indices of accumulated MAOM were greater for maize and soybean than oats and alfalfa, however, most carbohydrates in MAOM were plant-derived regardless of litter quality. At the end of the incubations, more of the accumulated MAOM-N was potentially mineralizable in soils amended with high quality litters. Nevertheless, most of the litter-C remained as residual litter; just 12% was mineralized to CO2 and 13% was transferred to MAOM. Our results demonstrate several unexpected effects of litter quality on MAOM stabilization including the direct stabilization of plant-derived carbohydrates

Laser modulated optical reflectance of thin semiconductor films on glass

Semiconductor films, deposited by reactive magnetron sputtering on glass substrates have been analyzed with the help of laser-modulated optical reflectance. The results are discussed with respect to the thermal and charge carrier transport properties. Semiconductor properties have been identified both for micro-crystalline and amorphous film