Harvest frequency (HF) and fertilizer effects on biomass production, nutrient removal, and ethanol yield must be understood to help guide management decisions in switchgrass ( Panicum virgatum L.) production. This 4‐yr study quantified yield and chemical composition responses of Alamo switchgrass to factorial combinations (4 × 2) of four HFs (harvesting one, two, three, or six times annually) and two N application rates (80 and 160 kg N ha −1 ) in a randomized complete block design experiment with three replications. In all years, yields decreased linearly with HF. In the one‐cut HF, yield increased from 8.8 in Year 1 to 14.7 Mg ha −1 in Year 3 and plateaued thereafter. For the two‐cut HF, yield was similar across years, averaging 10 Mg ha −1 , but for the three‐ and six‐cut HFs, yield increased from Year 1 to Year 2 and declined by Year 4. Nutrient concentration increased with HF, while nutrient removal responses fluctuated among elements. Acid detergent fiber, neutral detergent fiber, hemicellulose, cellulose, and lignin concentrations decreased with increasing HF, but there was no effect of N rate. In Years 1 and 2, theoretical ethanol production (TEP) was similar between the one‐ (3.7 kL ha −1 ) and two‐cut HFs (4.2 kL ha −1 ) but decreased as the HF increased to three (2.6–3.4 kL ha −1 ) and six cuts (1.4– 2.5 kL ha −1 ). In Years 3 and 4, TEP decreased linearly with increasing HF. Greater HF resulted in reduced feedstock yield, quality, ethanol yield, and production, but N application rate did not have any effect.
Sustainable nutrient management in high tunnel production is critical for optimizing crop yield and quality and improving soil health. In this study, we investigated the influence of different pre-plant composts (composted broiler litter, vemicompost, and cotton gin compost) in combination with different rates of organic or conventional fertilizer on zinnia plant growth, marketable yield of cut flower stems (>30 cm), and soil nutrients in a high tunnel over two years. Results showed that in general, pre-plant compost influenced plant growth, and plants that received composted broiler litter had the highest plant growth index. However, pre-plant compost did not affect the number of marketable cut stems. Fertigation during the growing season influenced the number of marketable cut stems. Comparable rates of nitrogen, from either organic or conventional fertilizer, produced similar numbers of marketable stems, suggesting that the organic fertilizer used in this study can be used as a fertilizer source for the production of zinnia cut flowers. After two years of production under the high tunnel, soil-extractable phosphorus, sodium, zinc, and pH significantly increased, suggesting that salt accumulation should be closely monitored in response to different compost or fertilizer sources with long-term production under high tunnels.
Since the first courses were offered in programming, plagiarism has been a perplexing problem. Detection techniques, administrative procedures, and penalties vary greatly. Instructors face an increasingly legalistic system when prosecuting plagiarism cases. Panel members will discuss the prevention, detection, and prosecution aspects of program plagiarism and will present legal and administrative views of the problem.
Abstract The Bayesian processor of forecast (BPF) is developed for a continuous predictand. Its purpose is to process a deterministic forecast (a point estimate of the predictand) into a probabilistic forecast (a distribution function, a density function, and a quantile function). The quantification of uncertainty is accomplished via Bayes theorem by extracting and fusing two kinds of information from two different sources: (i) a long sample of the predictand from the National Climatic Data Center, and (ii) a short sample of the official National Weather Service forecast from the National Digital Forecast Database. The official forecast is deterministic and hence deficient: it contains no information about uncertainty. The BPF remedies this deficiency by outputting the complete and well-calibrated characterization of uncertainty needed by decision makers and information providers. The BPF comes furnished with (i) the meta-Gaussian model, which fits meteorological data well as it allows all forms of marginal distribution functions, and nonlinear and heteroscedastic dependence structures, and (ii) the statistical procedures for estimation of parameters from asymmetric samples and for coping with nonstationarities in the predictand and the forecast due to the annual cycle and the lead time. A comprehensive illustration of the BPF is reported for forecasts of the daily maximum temperature issued with lead times of 1, 4, and 7 days for three stations in two seasons (cool and warm).
This paper illustrates a statistical model-based approach to the problem of target detection in a cluttered scene from long-wave infrared images, accommodating both unknown range to the target, unknown target location in the image, and unknown gain control settings on the imaging device. The philosophical perspective adopted emphasizes an iterative process of model creation and refinement and subsequent evaluation. The overarching theme is on the clear statement of all assumptions regarding the relationships between ground truth and corresponding imagery, the assurance that each admits quantifiable refutation, and the opportunity costs associated with their adoption for a particular problem.
Six potato cultivars (Atlantic, Sebago, Onaway, Russet Burbank, Lemhi Russet,and Norland) were evaluated for phosphorus uptake efficiency in solution culture. Individual rooted cuttings of each cultivar were transferred from a standard 1/5 Hoagland's solution into solutions containing one of six P concentrations (0.05,0.1,0.22,0.5,1.1 and 2.3mg/l). After a 24h adjustment period P uptake was followed over a 6h period by collecting solution aliquots every two hours. All cultivars depleted the two lowest initial P concentrations to similar stable P concentration. The P uptake rate per unit length of root showed a sigmoidal relationship to the initial P solution concentration. The general nature of the P uptake relation to solution P concentration was similar among the cultivars, although the actual values varied. In general, P uptake rate increased from 5.0 × 10 -4 at the lowest concentration to 7.0 × 10 -2 μg·cm -1 ·h -1 at the highest P solution concentration.
Abstract Pulp and paper mills often burn wood waste to fuel their boilers. The ash from a Mississippi pulp mill boiler was evaluated for potential use as an amendment to peat moss-based greenhouse substrates for production of young tomato plants. Between 0 and 50% ash was added to a custom-blended peat moss-based substrate, and these were compared to a commercially available substrate without ash. Addition of ash increased substrate pH, conductivity (EC), bulk density and water holding capacity, while reducing airspace and average particle size. In general, tomato plants grown in 0–40% ash had similar growth indexes as plants grown in commercial substrate. Increasing amounts of ash decreased tomato shoot nitrogen (N), potassium (K), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) concentration, and increased concentrations of phosphorus (P), calcium (Ca), sulfur (S), and boron (B). These results indicate that pulp mill ash has the potential to be used as a substrate component for greenhouse container production of tomato. Keywords: mediapeatmossgrowth indexpHlimewaste utilizationwood ash
