Model and Sensor-Based Recommendation Approaches for In-Season Nitrogen Management in Corn

Nitrogen management for corn (Zea mays L.) may be improved by applying a portion of N in-season. This investigation was conducted to evaluate crop modeling (Maize-N) and active crop canopy sensing approaches for recommending in-season N fertilizer rates. These approaches were evaluated during 2012–2013 on 11 field sites, in Missouri, Nebraska, and North Dakota. Nitrogen management also included a no-N treatment (check) and a non-limiting N reference (all at planting). Nitrogen management treatments were assessed for two hybrids and at low and high seeding rates, arranged in a randomized complete block design. In 9 of 11 site-years, the sensor-based approach recommended lower in-season N rates than the model (collectively 59% less N), resulting in trends of higher partial factor productivity of nitrogen (PFPN) and higher agronomic efficiency (AE) than the model. However, yield was better protected by the model-based approach. In some situations, canopy sensing excelled at optimizing the N rate for localized conditions. With abnormally warm and moist soil conditions for the 2012 Nebraska sites and presumed high levels of inorganic N from mineralization, N application was appropriately reduced, resulting in no yield decrease and N savings compared to the non-limiting N reference. Depending on the site, both recommendation approaches were successful; a combination of model and sensor information may optimize in-season decision support for N recommendation

Model and Sensor-Based Recommendation Approaches for In-Season Nitrogen Management in Corn

Nitrogen management for corn (Zea mays L.) may be improved by applying a portion of N in-season. This investigation was conducted to evaluate crop modeling (Maize-N) and active crop canopy sensing approaches for recommending in-season N fertilizer rates. These approaches were evaluated during 2012–2013 on 11 field sites, in Missouri, Nebraska, and North Dakota. Nitrogen management also included a no-N treatment (check) and a non-limiting N reference (all at planting). Nitrogen management treatments were assessed for two hybrids and at low and high seeding rates, arranged in a randomized complete block design. In 9 of 11 site-years, the sensor-based approach recommended lower in-season N rates than the model (collectively 59% less N), resulting in trends of higher partial factor productivity of nitrogen (PFPN) and higher agronomic efficiency (AE) than the model. However, yield was better protected by the model-based approach. In some situations, canopy sensing excelled at optimizing the N rate for localized conditions. With abnormally warm and moist soil conditions for the 2012 Nebraska sites and presumed high levels of inorganic N from mineralization, N application was appropriately reduced, resulting in no yield decrease and N savings compared to the non-limiting N reference. Depending on the site, both recommendation approaches were successful; a combination of model and sensor information may optimize in-season decision support for N recommendation

Development and Validation of the Vending Evaluation for Nutrient-Density (VEND)ing Audit

Background: This paper describes the development and validation of the Vending Evaluation for Nutrient-Density (VEND)ing audit to comprehensively evaluate vended products based upon healthfulness, price and promotion, and machine accessibility. Methods: A novel vending nutrient-density score was created to determine the healthfulness of vended snack/beverage products. Field tested in United States colleges, VENDing audit (∑nutrient-density + 10 × % healthy products) and Support sub-scores (price + promotion + accessibility) were calculated for snack/beverage machines. Higher scores indicate more healthful vending options and supports for choosing healthfully. Nutrition Environment Measures Survey-Vending (NEMS-V) was used to validate the nutrient-density score for a sub-sample of machines. Sensitivity and specificity were computed by comparing the number of healthy snacks/beverages determined by NEMS-V and the VENDing nutrient-density scores. Results: Researchers conducted the VENDing audit on 228 snack/beverage vending machines at 9 universities within the United States and used both VENDing and NEMS-V on 33 snack and 52 beverage vending machines. Mean VENDing audit scores were 4.5 ± 2.0 (2.6, 3.4) and 2.6 ± 2.0 (0, 12) for snack/beverage machines, respectively. The number of products considered healthy assessed with both the VENDing nutrient-density scores and the NEMS-V were positively correlated for beverages (r = 0.687, p\u3c 0.001) and snacks (r = 0.366, p \u3c 0.05). The sensitivity was excellent for beverages (0.83) and moderate for snacks (0.69); while the specificity was moderate for both beverages (0.66) and snacks (0.50). Conclusions: The VENDing audit uses unique, valid, and reliable nutrient-density scoring to evaluate snacks/beverages along a continuum of healthful criteria and comprehensively evaluates the full vending environment

The Mineral Assemblage of Caves Within Şălitrari Mountain (Cerna Valley, SW Romania): Depositional Environment and Speleogenetic Implications

Eighteen minerals belonging to eight chemical groups were identified from three caves within Şălitrari Mountain, in the upper Cerna River basin (Romania) by means of scanning electron microscopy, electron microprobe analysis, and X-ray powder diffraction. One passage in the Great Cave from Şălitrari Mountain, the largest cave investigated, exhibits abnormal relative humidity and temperature ranges, allowing for a particular depositional environment. The cave floor is covered by alluvial sediments (ranging from cobble, sand, and clay to silt-sized material), bear bones, bat guano, and rubble. These materials reacted with percolating meteoric water and hydrogen sulfide-rich hypogene hot solutions, precipitating a variety of secondary minerals. Most of these minerals are common in caves (e.g. calcite, gypsum, brushite), however, some of them (alunite, aluminite, and darapskite) require very particular environments in order to form and persist. Cave passage morphologies suggest a complex speleogenetic history that includes changes from phreatic to vadose conditions. The latter was punctuated by a sulfuric acid dissolution/precipitation phase, partly overprinted by present-day vadose processes. The cave morphology and the secondary minerals associated with the alluvial sediments in these caves are used to unravel the region’s speleogenetic history