Individual tree and stand-level carbon and nutrient contents across one rotation of loblolly pine plantations on a reclaimed surface mine

While reclaimed loblolly pine (Pinus taeda L.) plantations in east Texas, USA have demonstrated similar aboveground productivity levels relative to unmined forests, there is interest in assessing carbon (C) and nutrients in aboveground components of reclaimed trees. Numerous studies have previously documented aboveground biomass, C, and nutrient contents in loblolly pine plantations; however, similar data have not been collected on mined lands. We investigated C, N, P, K, Ca, and Mg aboveground contents for first-rotation loblolly pine growing on reclaimed mined lands in the Gulf Coastal Plain over a 32-year chronosequence and correlated elemental rates to stand age, stem growth, and similar data for unmined lands. At the individual tree level, we evaluated elemental contents in aboveground biomass components using tree size, age, and site index as predictor variables. At the stand-level, we then scaled individual tree C and nutrients and fit a model to determine the sensitivity of aboveground elemental contents to stand age and site index. Our data suggest that aboveground C and nutrients in loblolly pine on mined lands exceed or follow similar trends to data for unmined pine plantations derived from the literature. Diameter and height were the best predictors of individual tree stem C and nutrient contents (R ≥ 0.9473 and 0.9280, respectively) followed by stand age (R ≥ 0.8660). Foliage produced weaker relationships across all predictor variables compared to stem, though still significant (P ≤ 0.05). The model for estimating stand-level C and nutrients using stand age provided a good fit, indicating that contents aggrade over time predictably. Results of this study show successful modelling of reclaimed loblolly pine aboveground C and nutrients, and suggest elemental cycling is comparable to unmined lands, thus providing applicability of our model to related systems

Processing of wild sunflower with different moisture contents into solid bio fuel

Wild Sunflower stems were gathered and shredded using locally fabricated biomass shredder available at the Research Office of Benguet State University,and were processed into the desired size and moisture contents. Right after the briquetting operation, the physical properties of the briquette were measured and then stored in a zip bag for 24 hours. After the storage, same measurement was conducted.Results show that the influence of moisture contents on the average mass, dimension,shattering resistance,volume anddensity was statistically insignificant.The wild sunflower with moisture content of 16%had the highest shattering resistance of 88.85%.Furthermore, the influence of moisture content on the thermal properties like ignition time, burning time and ash content are statistically insignificant. Among the moisture contents, the fastest ignition time of 43.75 sec with longest burning time was recorded under 12%. Ash content was also lowest at 12%Vytauto Didžiojo universitetasŽemės ūkio akademij

Concept design of a portable carrot seeder

A concept design of a carrot seeder, filed for patent application, was successfully developed in this study. Farmers were visited and interviewed and the data regarding their existing practices in planting carrots, corresponding tools and equipment and planting requirements such as hill spacing, row spacing and plant bed size were gathered. These data were used as input in the preparation and simulation of the seeder design with the aid of Solidworks software. The seeder consisted of seed metering assembly, frame, ground wheels, skid, handle, power transmission, furrow opener and seed covering mechanism. It has 5 metering discs and the spacing between rows is adjustable. The metering disc is provided with grooves on its periphery of size that can accommodate 2 to 5 carrot seeds. Draft force to push the device in usage is 10 kgforce. The designed overall weight is 12 kgVytauto Didžiojo universitetasŽemės ūkio akademij

Combustion of Biomass

28 page(s